From owner-synth-diy Mon Oct 2 20:09:08 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA143769; Mon, 2 Oct 1995 20:09:08 GMT Received: from fibermux.fibermux.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA145812; Mon, 2 Oct 1995 21:09:03 +0100 Received: from ccrelay.fibermux.com by fibermux.fibermux.com (4.1/SMI-4.1) id AA16300; Mon, 2 Oct 95 13:11:43 PDT Received: from cc:Mail by ccrelay.fibermux.com id AA812664557; Mon, 02 Oct 95 13:06:24 PDT Date: Mon, 02 Oct 95 13:06:24 PDT From: gstopp@fibermux.com Encoding: 12 Text Message-Id: <9509028126.AA812664557@ccrelay.fibermux.com> To: synth-diy@horus.sara.nl Subject: CEM Data Sheets Sender: owner-synth-diy@horus.sara.nl Precedence: bulk Hi, Anybody out there got data sheets for the CEM3360 Dual VCA? I have all data sheets for 3310/3320/3330/3340, but not for the 3360. I would like to get a copy via fax, if possible. Thanks, Gene p.s. actually any other data sheets than those I just mentioned too..... From owner-synth-diy Tue Oct 3 13:21:58 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA104634; Tue, 3 Oct 1995 13:21:58 GMT Received: from localhost.sara.nl by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AB40371; Tue, 3 Oct 1995 14:21:55 +0100 Message-Id: <9510031321.AB40371@horus.sara.nl> To: Synthesizer DIY list Subject: Mail problems at SARA Date: Tue, 03 Oct 1995 14:21:55 +0100 From: Rick Jansen Sender: owner-synth-diy@horus.sara.nl Precedence: bulk The past 5 days the mail system at SARA has experienced major problems. These have been fixed, but it will be a few days till all queues have been processed. No mail is lost. Rick Jansen __ rick@sara.nl http://www.sara.nl/Rick.Jansen _____________________________________________ S&H's a module and s&h's looking good From owner-synth-diy Tue Oct 3 14:17:28 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA142903; Tue, 3 Oct 1995 14:17:28 GMT Received: from ix6.ix.netcom.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA85541; Tue, 3 Oct 1995 15:17:25 +0100 Received: from by ix6.ix.netcom.com (8.6.12/SMI-4.1/Netcom) id HAA11428; Tue, 3 Oct 1995 07:17:15 -0700 Date: Tue, 3 Oct 1995 07:17:15 -0700 Message-Id: <199510031417.HAA11428@ix6.ix.netcom.com> From: chordman@ix.netcom.com (Scott Gravenhorst, Synthaholic) Subject: Hello, is there anyone here? To: synth-diy@horus.sara.nl Sender: owner-synth-diy@horus.sara.nl Precedence: bulk I haven't gotten mail from this list in over a week. I also don't see bounce messages when I post. I don't get carbons either. Will someone on this list please email me so I know it's alive? -- -- Scott G., Synthaholic There is no 12 step program for synthaholics. Thank your Superior Being. From owner-synth-diy Tue Oct 3 15:58:47 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA152783; Tue, 3 Oct 1995 15:58:47 GMT Received: from wdus06.wdc.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA153033; Tue, 3 Oct 1995 16:58:43 +0100 Message-Id: <9510031558.AA153033@horus.sara.nl> Received: with SMTP-MR; Tue, 3 Oct 1995 08:53 PST Date: Tue, 3 Oct 1995 16:51 PST From: Barry Klein 714-932-7493 Subject: Ok, posting something now...... To: SYNTH-DIY@horus.sara.nl Content-Type: TEXT Posting-Date: Tue, 3 Oct 1995 16:52 PST Importance: normal Priority: non-urgent X-Hop-Count: 1 A1-Type: MAIL Sender: owner-synth-diy@horus.sara.nl Precedence: bulk Ok, I'll post something............. For those who have a copy of my book, either old or new, I found a few more errors in a circuit that you might want to correct. Figure 5-28 a state variable filter with the CEM3320: 1. R3 ties to -15V. 2. R1 goes to pin 2 of the LM13600 (diode bias). 3. R50/51 junction goes to pin 12 not pin 7 of the CEM3320. Barry klein_b@a1.wdc.com From owner-synth-diy Tue Oct 3 21:10:16 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA28741; Tue, 3 Oct 1995 21:10:16 GMT Received: from ix8.ix.netcom.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA144958; Tue, 3 Oct 1995 22:10:08 +0100 Received: from by ix8.ix.netcom.com (8.6.12/SMI-4.1/Netcom) id OAA13711; Tue, 3 Oct 1995 14:10:02 -0700 Date: Tue, 3 Oct 1995 14:10:02 -0700 Message-Id: <199510032110.OAA13711@ix8.ix.netcom.com> From: chordman@ix.netcom.com (Scott Gravenhorst, Synthaholic) Subject: TEST Please ignore To: synth-diy@horus.sara.nl Sender: owner-synth-diy@horus.sara.nl Precedence: bulk But if you do read this, I got an "already s*bscribed" message from majordummy. At least that's different than the last time which was resounding nothingness. -- -- Scott G., Synthaholic There is no 12 step program for synthaholics. Thank your Superior Being. From owner-synth-diy Wed Oct 4 00:41:36 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA114330; Wed, 4 Oct 1995 00:41:36 GMT Received: from ix2.ix.netcom.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA24968; Wed, 4 Oct 1995 01:41:33 +0100 Received: from by ix2.ix.netcom.com (8.6.12/SMI-4.1/Netcom) id RAA16785; Tue, 3 Oct 1995 17:41:58 -0700 Date: Tue, 3 Oct 1995 17:41:58 -0700 Message-Id: <199510040041.RAA16785@ix2.ix.netcom.com> From: chordman@ix.netcom.com (Scott Gravenhorst, Synthaholic) Subject: TEST: IGNORE. Last one from me (I hope) To: synth-diy@horus.sara.nl Sender: owner-synth-diy@horus.sara.nl Precedence: bulk test test -- -- Scott G., Synthaholic There is no 12 step program for synthaholics. Thank your Superior Being. From owner-synth-diy Thu Oct 5 03:17:53 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA137072; Thu, 5 Oct 1995 03:17:53 GMT Received: from ix5.ix.netcom.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA100458; Thu, 5 Oct 1995 04:17:49 +0100 Received: from by ix5.ix.netcom.com (8.6.12/SMI-4.1/Netcom) id UAA12095; Wed, 4 Oct 1995 20:16:37 -0700 Date: Wed, 4 Oct 1995 20:16:37 -0700 Message-Id: <199510050316.UAA12095@ix5.ix.netcom.com> From: chordman@ix.netcom.com (Scott Gravenhorst, Synthaholic) Subject: FatMan and PLL To: analogue@hyperreal.com Cc: synth-diy@horus.sara.nl Sender: owner-synth-diy@horus.sara.nl Precedence: bulk After reading John Simonton's post about the LED mod to allow the VCOs to run much closer in frequency without locking, I tried it and it worked very well. You can get a real slow phase effect. However, if you have built or will build the PLL addition to the FatMan, the PLL causes interference in the form of the VCOs locking to the PLL signal, apparently via power supply coupling. I solved the problem by building a separate -12V power supply for the CMOS logic. Simply copy the -12V supply circuit in the FatMan schematic. I used a separated transformer as well. I plug both wall warts into a switched outlet bar and control power from the outlet bar. All interference is eliminated in this manner. Sorry for any inconvenience. -- -- Scott G., Synthaholic There is no 12 step program for synthaholics. Thank your Superior Being. From owner-synth-diy Fri Oct 6 02:49:12 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA117909; Fri, 6 Oct 1995 02:49:12 GMT Received: from ix.ix.netcom.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA128655; Fri, 6 Oct 1995 03:49:09 +0100 Received: from by ix.ix.netcom.com (8.6.12/SMI-4.1/Netcom) id TAA00246; Thu, 5 Oct 1995 19:48:29 -0700 Date: Thu, 5 Oct 1995 19:48:29 -0700 Message-Id: <199510060248.TAA00246@ix.ix.netcom.com> From: chordman@ix.netcom.com (Scott Gravenhorst, Synthaholic) Subject: Anyone know what this IC is? To: analogue@hyperreal.com Cc: synth-diy@horus.sara.nl Sender: owner-synth-diy@horus.sara.nl Precedence: bulk I have 4 of these MM5056 ICs The logo is familiar, but I don't know what it is either. -------+ | | | +-- | | sort of like that. Anyway, I think they have audio applications, but I'm not sure. I would appreciate any info. I looked thru my files and I don't find a spec sheet, which I usually get and always keep. -- -- Scott G., Synthaholic There is no 12 step program for synthaholics. Thank your Superior Being. From owner-synth-diy Fri Oct 6 16:09:04 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA73414; Fri, 6 Oct 1995 16:09:04 GMT Received: from fibermux.fibermux.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA32182; Fri, 6 Oct 1995 17:08:46 +0100 Received: from ccrelay.fibermux.com by fibermux.fibermux.com (4.1/SMI-4.1) id AA21296; Fri, 6 Oct 95 09:00:12 PDT Received: from cc:Mail by ccrelay.fibermux.com id AA812995128; Fri, 06 Oct 95 08:56:23 PDT Date: Fri, 06 Oct 95 08:56:23 PDT From: gstopp@fibermux.com Encoding: 39 Text Message-Id: <9509068129.AA812995128@ccrelay.fibermux.com> To: analogue@hyperreal.com Cc: synth-diy@horus.sara.nl Subject: Re: Anyone know what this IC is? Sender: owner-synth-diy@horus.sara.nl Precedence: bulk The logo looks like it might be AMD, but ASCII graphics is a little imprecise.... According to IC Master the MSM5056 is an LCD Driver/ALU (!) made by OKI Semiconductors. No other 5056's are listed. I suspect that they are older chips (IC Master tends to not list out-of-production chips). Also AMD is big on memory and CPU's etc. - not audio! I'm all confused. How many pins on the chip? ______________________________ Reply Separator _________________________________ Subject: Anyone know what this IC is? Author: ,chordman@ix.netcom.com (Scott Gravenhorst, Synthaholic) at ccrelayout Date: 10/5/95 7:53 PM I have 4 of these MM5056 ICs The logo is familiar, but I don't know what it is either. -------+ | | | +-- | | sort of like that. Anyway, I think they have audio applications, but I'm not sure. I would appreciate any info. I looked thru my files and I don't find a spec sheet, which I usually get and always keep. -- -- Scott G., Synthaholic There is no 12 step program for synthaholics. Thank your Superior Being. From owner-synth-diy Mon Oct 9 12:10:25 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA104431; Mon, 9 Oct 1995 12:10:25 GMT Received: from ns.scn.de by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA57311; Mon, 9 Oct 1995 13:10:19 +0100 Received: (from uucp@localhost) by proxy.scn.de (8.6.11/8.6.11) id NAA14997; Mon, 9 Oct 1995 13:06:54 +0100 Received: from marina.scn.de(192.129.41.2) by proxy.scn.de via smap (V1.3) id sma014970; Mon Oct 9 13:06:40 1995 Received: (from uucp@localhost) by marina.scn.de (8.6.11/8.6.11) id NAA18869; Mon, 9 Oct 1995 13:09:41 +0100 Received: from r316.m30x.nbg.scn.de(142.120.5.16) by marina.scn.de via smap (V1.3) id sma018800; Mon Oct 9 13:09:20 1995 Received: from msmgate.m30x.nbg.scn.de by r316.m30x.nbg.scn.de id aa11631; 9 Oct 95 13:08 MEZ Received: by MSMGATE.M30X.NBG.SCN.DE with Microsoft Mail id <30798173@MSMGATE.M30X.NBG.SCN.DE>; Mon, 09 Oct 95 13:09:23 PDT From: Haible_Juergen#Tel2743 To: analogue , bode , DIY Subject: AN829 VCA chip ? Date: Mon, 09 Oct 95 13:09:00 PDT Message-Id: <30798173@MSMGATE.M30X.NBG.SCN.DE> Encoding: 11 TEXT X-Mailer: Microsoft Mail V3.0 Sender: owner-synth-diy@horus.sara.nl Precedence: bulk Hi! I found this one in my new Lambda. Must be some crude dual VCA chip. I'd like to know more about its specs, but alas our oldest IC Master is from 1988. Could anybody please look it up for me in an older issue? Thanks, JH. From owner-synth-diy Mon Oct 9 18:30:19 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA23832; Wed, 27 Sep 1995 18:37:34 GMT Received: from mail-e1a.megaweb.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA127762; Wed, 27 Sep 1995 19:37:31 +0100 Received: from www-14-152.gnn.com. (www-14-152.gnn.com [205.188.14.152]) by mail-e1a.megaweb.com (8.6.11/8.6.9) with SMTP id OAA19716; Wed, 27 Sep 1995 14:34:45 -0400 Message-Id: <199509271834.OAA19716@mail-e1a.megaweb.com> X-Mailer: GNNmessenger 1.1 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Wed, 27 Sep 1995 11:35:26 From: RevLazlo@megaweb.com (lazlo) To: analogue@hyperreal.com Subject: LIBERATION CORD=6 pin connector Cc: synth-diy@horus.sara.nl Sender: owner-synth-diy@horus.sara.nl Precedence: bulk i'm after the elusive 6 pin bullet (xlr) connector that switch craft use to make. i need it for a MOOG LIBERATION keyboard/module connector. if you have any of these (or know anyone that does) please contact me. i'm kind of desperate to get these (setting himself up for price jacking, knowingly !!!). thanks -tony ______________________________________________________________________ THEE NAME: tony patrick blake THEE FORMS OF CONTACT: THEE E-MAIL MAIN: RevLazlo@megaweb.com THEE E-MAIL ALTERNATE: tpb2@lehigh.edu THEE V-MAIL: 610-231-9320 THEE V-PERSON: Unknown @ this time THEE PERTINENT EQUIPMENT: Ensoiq ASR-10, Roland JUNO-106, Roland SH-101, Roland MKS-50 (w/PG300), Oberheim DMX, Alesis SR-16, Technics SL1200mkII *2, Gemini PDM3008, Custom Stratocastor (almost finished) ______________________________________________________________________ From owner-synth-diy Mon Oct 9 18:45:12 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA143769; Mon, 2 Oct 1995 20:09:08 GMT Received: from fibermux.fibermux.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA145812; Mon, 2 Oct 1995 21:09:03 +0100 Received: from ccrelay.fibermux.com by fibermux.fibermux.com (4.1/SMI-4.1) id AA16300; Mon, 2 Oct 95 13:11:43 PDT Received: from cc:Mail by ccrelay.fibermux.com id AA812664557; Mon, 02 Oct 95 13:06:24 PDT Date: Mon, 02 Oct 95 13:06:24 PDT From: gstopp@fibermux.com Encoding: 12 Text Message-Id: <9509028126.AA812664557@ccrelay.fibermux.com> To: synth-diy@horus.sara.nl Subject: CEM Data Sheets Sender: owner-synth-diy@horus.sara.nl Precedence: bulk Hi, Anybody out there got data sheets for the CEM3360 Dual VCA? I have all data sheets for 3310/3320/3330/3340, but not for the 3360. I would like to get a copy via fax, if possible. Thanks, Gene p.s. actually any other data sheets than those I just mentioned too..... From owner-synth-diy Mon Oct 9 21:45:05 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA144524; Mon, 9 Oct 1995 21:45:05 GMT Received: from wdus03.wdc.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA12908; Mon, 9 Oct 1995 22:45:01 +0100 Message-Id: <9510092145.AA12908@horus.sara.nl> Received: with SMTP-MR; Mon, 9 Oct 1995 14:41 PST Date: Mon, 9 Oct 1995 22:38 PST From: Barry Klein 714-932-7493 Subject: CEM datasheets To: SYNTH-DIY@horus.sara.nl Content-Type: TEXT Posting-Date: Mon, 9 Oct 1995 22:39 PST Importance: normal Priority: non-urgent X-Hop-Count: 1 A1-Type: MAIL Sender: owner-synth-diy@horus.sara.nl Precedence: bulk All CEM/SSM data sheets are available in my Electronic Music IC Databook, along with the Curtis Synthesource app. notes. I think the CEM 3360 is in there - I don't have a copy here to check. Write me if you want more info. Also please post your address with your messages for private replies (such as this could have been). I'd like to ask you some questions regarding your moog ladder filter. Barry klein_b@a1.wdc.com From owner-synth-diy Mon Oct 9 22:32:49 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA124194; Mon, 9 Oct 1995 22:32:49 GMT Received: from ix7.ix.netcom.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA150301; Mon, 9 Oct 1995 23:32:46 +0100 Received: from by ix7.ix.netcom.com (8.6.12/SMI-4.1/Netcom) id OAA23240; Mon, 9 Oct 1995 14:54:24 -0700 Date: Mon, 9 Oct 1995 14:54:24 -0700 Message-Id: <199510092154.OAA23240@ix7.ix.netcom.com> From: chordman@ix.netcom.com (Scott Gravenhorst, Synthaholic) Subject: Thank you, it seems to be working To: synth-diy@horus.sara.nl Sender: owner-synth-diy@horus.sara.nl Precedence: bulk Thanks to all who sent me email re: What's up with DIY. Several others had the same problem. All of my old posts have now appeared in 'carbon'. What ever furball was stuck in there seems to have been recently coughed up. No further replies are necessary. Thanks again. Sorry about non-DIY content. Actually, I am almost ready to post a schematic for a FatMan pitch LFO that is better than my last one. It is a modified version of the LFO on Ric Miller's Web Page. (Thanks Ric) I have a few things to iron out yet. I think I can post by the end of the week. -- -- Scott G., Synthaholic There is no 12 step program for synthaholics. Thank your Superior Being. From owner-synth-diy Tue Oct 10 07:46:53 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA50501; Tue, 10 Oct 1995 07:46:53 GMT Received: from mail-e1a.megaweb.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA50749; Tue, 10 Oct 1995 08:46:50 +0100 Received: from www-0-124.gnn.com. (www-0-124.gnn.com [205.188.0.124]) by mail-e1a.megaweb.com (8.6.11/8.6.9) with SMTP id DAA14703; Tue, 10 Oct 1995 03:44:12 -0400 Message-Id: <199510100744.DAA14703@mail-e1a.megaweb.com> X-Mailer: GNNmessenger 1.1 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Tue, 10 Oct 1995 00:44:10 From: RevLazlo@megaweb.com (lazlo) To: analogue@hyperreal.com Subject: juno voice chips Cc: synth-diy@horus.sara.nl Sender: owner-synth-diy@horus.sara.nl Precedence: bulk i went shop hopping today, and struck up a coversation with a service tech. we ended up in his little repair cubical, and he started showing me some of the stuff he had laying around. he pulled out what he said was a 106 voice chip. he said they are still available from roland for $15. evidently he has used them to build his own stuff. he claims they're pretty powerful outside the domain of the 106. there are two chips that work together, with a minimum of external components(ever looked inside a 106, i don't recal seeing to many discrete pieces) so what do you think. could we build some interesting modules with these things. anybody have any ideas. unfortunately i'm not anywhere close to being as technical as most of you, but to me it sounds like it has potential. -tony From owner-synth-diy Tue Oct 10 08:56:33 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA72733; Tue, 10 Oct 1995 08:56:33 GMT Received: from ns.scn.de by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA77590; Tue, 10 Oct 1995 09:56:28 +0100 Received: (from uucp@localhost) by proxy.scn.de (8.6.11/8.6.11) id JAA19736 for ; Tue, 10 Oct 1995 09:53:13 +0100 Received: from marina.scn.de(192.129.41.2) by proxy.scn.de via smap (V1.3) id sma019698; Tue Oct 10 09:52:43 1995 Received: (from uucp@localhost) by marina.scn.de (8.6.11/8.6.11) id JAA09262 for ; Tue, 10 Oct 1995 09:55:45 +0100 Received: from r316.m30x.nbg.scn.de(142.120.5.16) by marina.scn.de via smap (V1.3) id sma009184; Tue Oct 10 09:55:32 1995 Received: from msmgate.m30x.nbg.scn.de by r316.m30x.nbg.scn.de id aa15512; 10 Oct 95 9:54 MEZ Received: by MSMGATE.M30X.NBG.SCN.DE with Microsoft Mail id <12CFA22F@MSMGATE.M30X.NBG.SCN.DE>; Tue, 01 Jan 80 09:55:59 PST From: Haible_Juergen#Tel2743 To: DIY Subject: RE: Quick resistor question... Date: Tue, 10 Oct 95 09:54:00 PST Message-Id: <12CFA22F@MSMGATE.M30X.NBG.SCN.DE> Encoding: 18 TEXT X-Mailer: Microsoft Mail V3.0 Sender: owner-synth-diy@horus.sara.nl Precedence: bulk > Are metal film resitiors ALWAYS better than carbon? - They're more > expensive > and have better tolerance, but are they also more > tempurature-sensative? The opposite is true. MF resistors have far better tempco's than carbon types. But if You are asking about "always", then there are exceptions. Many years ago there were MF resistors from a large German shop that were more noisy than carbon types. But this should be the exception. BTW, most people underestimate the effect of resistor *value* on noise. Building filters for my vocoder with 470k resistors, the resistors produce more noise than a 741 opamp. (I used TL074, for other reasons, however). JH. From owner-synth-diy Tue Oct 10 14:26:50 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA55431; Tue, 10 Oct 1995 14:26:50 GMT Received: from xgw1.pal.xgw.fi by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA99455; Tue, 10 Oct 1995 15:26:42 +0100 Received: from netcontrol.netcontrol.fi (netcontrol.netcontrol.fi [193.210.7.1]) by mail.xgw.fi (8.6.11/8.6.4) with ESMTP id RAA00768 for ; Tue, 10 Oct 1995 17:36:21 +0200 Received: (from jocke@localhost) by netcontrol.netcontrol.fi (8.6.11/8.6.9) id QAA25399; Tue, 10 Oct 1995 16:26:13 +0200 Date: Tue, 10 Oct 1995 16:26:13 +0200 (EET) From: Joachim Verghese To: Synth DIY Subject: Re: LM13600 VCOs in Spec Sheet In-Reply-To: <199509291924.MAA26587@ix9.ix.netcom.com> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-synth-diy@horus.sara.nl Precedence: bulk On Fri, 29 Sep 1995 chordman@ix.netcom.com wrote: > I have the spec pages for the LM13600 and there are several VCOs. They > look linear from the math, which is what I need. > > Have any of you played with these circuits? I have played with them, but that was almost 15 years ago. The only thing I remember was that the VCO drifted a lot. As can be seen from the design equations, the transconductance is heavily dependent on temperature, even without an exponential converter. For serious VCOs I'd recommend the Electronotes designs, or discrete types such as those in the Odyssey, SEM or Prodigy. -joachim From owner-synth-diy Tue Oct 10 15:01:07 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA66476; Tue, 10 Oct 1995 15:01:07 GMT Received: from ns.scn.de by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA61078; Tue, 10 Oct 1995 16:01:02 +0100 Received: (from uucp@localhost) by proxy.scn.de (8.6.11/8.6.11) id PAA21528 for ; Tue, 10 Oct 1995 15:57:45 +0100 Received: from marina.scn.de(192.129.41.2) by proxy.scn.de via smap (V1.3) id sma021512; Tue Oct 10 15:57:08 1995 Received: (from uucp@localhost) by marina.scn.de (8.6.11/8.6.11) id QAA07820 for ; Tue, 10 Oct 1995 16:00:12 +0100 Received: from r316.m30x.nbg.scn.de(142.120.5.16) by marina.scn.de via smap (V1.3) id sma007731; Tue Oct 10 15:59:37 1995 Received: from msmgate.m30x.nbg.scn.de by r316.m30x.nbg.scn.de id aa17098; 10 Oct 95 15:58 MEZ Received: by MSMGATE.M30X.NBG.SCN.DE with Microsoft Mail id <12CFF783@MSMGATE.M30X.NBG.SCN.DE>; Tue, 01 Jan 80 16:00:03 PST From: Haible_Juergen#Tel2743 To: DIY Subject: Re: LM13600 VCOs in Spec Sheet Date: Tue, 10 Oct 95 15:59:00 PST Message-Id: <12CFF783@MSMGATE.M30X.NBG.SCN.DE> Encoding: 23 TEXT X-Mailer: Microsoft Mail V3.0 Sender: owner-synth-diy@horus.sara.nl Precedence: bulk >I have played with them, but that was almost 15 years ago. The only >thing I remember was that the VCO drifted a lot. As can be seen from >the design equations, the transconductance is heavily dependent on >temperature, even without an exponential converter. > >For serious VCOs I'd recommend the Electronotes designs, or discrete >types such as those in the Odyssey, SEM or Prodigy. Without having either circuit in front of me maybe I can just add something general: To avoid dependence of gm, the input of the OTA simply has to be quite overloaded, i.e. the long tailed pair inside just acting as as *switch* for the current that is forced into the emitters. Then the OTA's output just switches between the positive and negative value of the control current. I guess that's how the EN circuits work. But are the app note circuits really that different, concerning this ? JH. PS.: always take care that the differential input voltage is limeted to +/-5V while Your overdriving the input! From owner-synth-diy Tue Oct 10 15:29:02 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA101518; Tue, 10 Oct 1995 15:29:02 GMT Received: from desiree.teleport.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA84080; Tue, 10 Oct 1995 16:28:29 +0100 Received: from [204.245.212.159] (ip-pdx05-27.teleport.com [204.119.62.27]) by desiree.teleport.com (8.6.12/8.6.9) with SMTP id IAA02395; Tue, 10 Oct 1995 08:06:37 -0700 X-Sender: mr808@mail.teleport.com Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Sat, 9 Oct 1999 08:12:20 -0700 To: analogue@hyperreal.com From: Tidal Bass Generator Subject: Re: juno voice chips Cc: synth-diy@horus.sara.nl Sender: owner-synth-diy@horus.sara.nl Precedence: bulk At 5:44 PM 10/9/95, lazlo wrote: >so what do you think. could we build some interesting modules >with these things. anybody have any ideas. unfortunately i'm >not anywhere close to being as technical as most of you, but >to me it sounds like it has potential. My thoughts: I believe the Juno VCO chip requires a digitally controlled counter to sync to, which explains why the 106 sounds so lame in Unison mode. That makes it a very poor choice for experimenters. Also, there's no way of knowing how many of these Roland has in stock. It'd be better to leave them for fixing broken Junos. The ElectroNotes VCO Gene Stopp built, and the Chroma VCO both have low parts counts and are not that more difficult to build than an IC-based VCO. As for using a CEM part, why would you want your synth to have the same VCO sound as the numerous CEM based synths that were made? CEM stuff has a sameness about it that can dominate your sound, which is why I sold my Prophet 5 & 600. 808 From owner-synth-diy Wed Oct 11 14:16:58 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA96160; Wed, 11 Oct 1995 14:16:58 GMT Received: from ns.scn.de by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA105369; Wed, 11 Oct 1995 15:16:53 +0100 Received: (from uucp@localhost) by proxy.scn.de (8.6.11/8.6.11) id PAA14584; Wed, 11 Oct 1995 15:12:53 +0100 Received: from marina.scn.de(192.129.41.2) by proxy.scn.de via smap (V1.3) id sma014521; Wed Oct 11 15:12:12 1995 Received: (from uucp@localhost) by marina.scn.de (8.6.11/8.6.11) id PAA18072; Wed, 11 Oct 1995 15:15:17 +0100 Received: from r316.m30x.nbg.scn.de(142.120.5.16) by marina.scn.de via smap (V1.3) id sma017260; Wed Oct 11 15:14:14 1995 Received: from msmgate.m30x.nbg.scn.de by r316.m30x.nbg.scn.de id aa21267; 11 Oct 95 15:13 MEZ Received: by MSMGATE.M30X.NBG.SCN.DE with Microsoft Mail id <307C41CB@MSMGATE.M30X.NBG.SCN.DE>; Wed, 11 Oct 95 15:14:35 PDT From: Haible_Juergen#Tel2743 To: DIY , till Subject: OTA question Date: Wed, 11 Oct 95 15:14:00 PDT Message-Id: <307C41CB@MSMGATE.M30X.NBG.SCN.DE> Encoding: 24 TEXT X-Mailer: Microsoft Mail V3.0 Sender: owner-synth-diy@horus.sara.nl Precedence: bulk Hi! I got a question about OTA configurations. Using a CA3080 plus a buffer opamp, there are basically two possibillities to build VCA's or VC-integrators: (1) the OTA feeding a resistor/capacitor to gnd, plus an opamp as unity gain buffer (2) the ota feeding an inverter/inverting integrator built of an opamp and a resistor/capacitor in it's feedback loop. I wonder which approach is the "better" one. As we can use both inputs of the OTA, signal inversion should not be a point. As far as I can guess, (2) would be easier for the OTA's output stages (constant Vce), but there might be advantages of (1) as well. Any ideas? Any pointer to good literature about this ? Thanks, JH. From owner-synth-diy Wed Oct 11 17:30:49 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA86351; Wed, 11 Oct 1995 17:30:49 GMT Received: from netcom16.netcom.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA75077; Wed, 11 Oct 1995 18:30:45 +0100 Received: by netcom16.netcom.com (8.6.12/Netcom) id JAA03642; Wed, 11 Oct 1995 09:57:00 -0700 Date: Wed, 11 Oct 1995 09:57:00 -0700 Message-Id: <199510111657.JAA03642@netcom16.netcom.com> To: HJ2743@denbgm3xm.scnn1.msmgate.m30x.nbg.scn.de Cc: synth-diy@horus.sara.nl In-Reply-To: <307C41CB@MSMGATE.M30X.NBG.SCN.DE> (message from Haible_Juergen#Tel2743 on Wed, 11 Oct 95 15:14:00 PDT) Subject: Re: OTA question Reply-To: don@till.com From: Don Tillman Organization: Don's house, Palo Alto, California Sender: owner-synth-diy@horus.sara.nl Precedence: bulk From: Haible_Juergen Date: Wed, 11 Oct 95 15:14:00 PDT Using a CA3080 plus a buffer opamp, there are basically two possibillities to build VCA's or VC-integrators: (1) the OTA feeding a resistor/capacitor to gnd, plus an opamp as unity gain buffer (2) the ota feeding an inverter/inverting integrator built of an opamp and a resistor/capacitor in it's feedback loop. If it were my design, I would do a variation of (1) with the OTA feeding a capacitor/resistor to ground and buffer it with an FET source follower. This will keep the circuit free of nasty opamp-style feedback. Also I'd use a 13600 or 3280 instead of the 3080 for the obvious noise reasons. And if you use the 3280, you get to decide whether you want to control the gain, the attenuation, or some combination of the two, which should provide for some variations in the character of the circuit. -- Don From owner-synth-diy Wed Oct 11 19:02:44 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA92728; Wed, 11 Oct 1995 19:02:44 GMT Received: from fibermux.fibermux.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA93999; Wed, 11 Oct 1995 20:02:38 +0100 Received: from ccrelay.fibermux.com by fibermux.fibermux.com (4.1/SMI-4.1) id AA27541; Wed, 11 Oct 95 12:05:19 PDT Received: from cc:Mail by ccrelay.fibermux.com id AA813438314; Wed, 11 Oct 95 11:59:20 PDT Date: Wed, 11 Oct 95 11:59:20 PDT From: gstopp@fibermux.com Encoding: 35 Text Message-Id: <9509118134.AA813438314@ccrelay.fibermux.com> To: synth-diy@horus.sara.nl Subject: Unusual panel parts Sender: owner-synth-diy@horus.sara.nl Precedence: bulk Hi all, Just got finished designing and testing a state variable filter that runs off of a 9 volt battery and is manually tuned (not voltage controlled). It's real simple and sounds great but it requires a dual pot for the tuning of the frequency. This brought up a question - where do you get dual pots these days? I have many junk drawers so no problem for me, but what advice would I give to other builders? Here are the possible sources: 1. Buy it new and pay through the nose. One of my local stores will put together any pot you want using their TRW pot component selection. This costs between $5-$10 per unit. 2. Find them surplus. You gotta take what you can find this way. 3. Go to garage sales and buy old stereos. The garage sale option is a great source not only for dual pots, but for concentric-shaft dual pots and center-tapped pots as well. Not only that but there are even some cool switches, meters, and other panel thingeys to be had. Usually you can use these parts and find your own knobs, but for the dual concentric pots you may have to use the knobs they come with. The center-tapped pots are useful for two-source attenuators like the modulation pots on the Oberheim SEM. Dual concentric pots can be used to save space on fine/course tuning controls for VCO's. Meters can be useful for mic pre-amps. As I sit here and type this I'm looking at a bag of dual concentric center-tapped pots with cool knobs stolen from some junk stereo, wondering what kind of noisemaker I can create with them. (Sick, huh?) Anyway just a builder's thought for the day..... - Gene From owner-synth-diy Thu Oct 12 08:46:13 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA62675; Thu, 12 Oct 1995 08:46:13 GMT Received: from xgw1.pal.xgw.fi by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA85190; Thu, 12 Oct 1995 09:46:07 +0100 Received: from netcontrol.netcontrol.fi (netcontrol.netcontrol.fi [193.210.7.1]) by mail.xgw.fi (8.6.11/8.6.4) with ESMTP id LAA31030 for ; Thu, 12 Oct 1995 11:56:20 +0200 Received: (from jocke@localhost) by netcontrol.netcontrol.fi (8.6.11/8.6.9) id KAA29772; Thu, 12 Oct 1995 10:45:47 +0200 Date: Thu, 12 Oct 1995 10:45:46 +0200 (EET) From: Joachim Verghese To: Synth DIY Subject: Re: OTA question In-Reply-To: <199510111657.JAA03642@netcom16.netcom.com> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-synth-diy@horus.sara.nl Precedence: bulk On Wed, 11 Oct 1995, Don Tillman wrote: > If it were my design, I would do a variation of (1) with the OTA > feeding a capacitor/resistor to ground and buffer it with an FET > source follower. This will keep the circuit free of nasty opamp-style > feedback. Nasty feedback? Interesting. Can you elaborate a little? thanks, -joachim From owner-synth-diy Thu Oct 12 09:42:23 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA91690; Thu, 12 Oct 1995 09:42:23 GMT Received: from ns.scn.de by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA64035; Thu, 12 Oct 1995 10:42:19 +0100 Received: (from uucp@localhost) by proxy.scn.de (8.6.11/8.6.11) id KAA15258; Thu, 12 Oct 1995 10:38:39 +0100 Received: from marina.scn.de(192.129.41.2) by proxy.scn.de via smap (V1.3) id sma015218; Thu Oct 12 10:38:30 1995 Received: (from uucp@localhost) by marina.scn.de (8.6.11/8.6.11) id KAA00532; Thu, 12 Oct 1995 10:41:36 +0100 Received: from r316.m30x.nbg.scn.de(142.120.5.16) by marina.scn.de via smap (V1.3) id sma000464; Thu Oct 12 10:41:15 1995 Received: from msmgate.m30x.nbg.scn.de by r316.m30x.nbg.scn.de id aa24490; 12 Oct 95 10:40 MEZ Received: by MSMGATE.M30X.NBG.SCN.DE with Microsoft Mail id <307D5353@MSMGATE.M30X.NBG.SCN.DE>; Thu, 12 Oct 95 10:41:39 PDT From: Haible_Juergen#Tel2743 To: DIY , till Subject: Re: OTA question Date: Thu, 12 Oct 95 10:40:00 PDT Message-Id: <307D5353@MSMGATE.M30X.NBG.SCN.DE> Encoding: 24 TEXT X-Mailer: Microsoft Mail V3.0 Sender: owner-synth-diy@horus.sara.nl Precedence: bulk > >If it were my design, I would do a variation of (1) with the OTA >feeding a capacitor/resistor to ground and buffer it with an FET >source follower. This will keep the circuit free of nasty opamp-style >feedback. > >Also I'd use a 13600 or 3280 instead of the 3080 for the obvious noise >reasons. Thanks for the answer. I use the 13600/13700 almost every time, and I have used all three methods (discrete, follower, inverter) in different projects myself - but what I was really looking for was some theory about the two alternatives I named (in *some* applications the level shift of a discrete buffer is not that good). I was really asking about pro's and cons of the two named alternatives, and to make it easy I named a 3080. I might add that opamps I use to use the TL07x series. So given these to components (for what reason ever) - what would the pro's and con's for either configuration? Thanks, JH. From owner-synth-diy Thu Oct 12 12:37:17 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA105673; Thu, 12 Oct 1995 12:37:17 GMT Received: from ns.scn.de by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA101309; Thu, 12 Oct 1995 13:37:12 +0100 Received: (from uucp@localhost) by proxy.scn.de (8.6.11/8.6.11) id NAA02016 for ; Thu, 12 Oct 1995 13:33:47 +0100 Received: from marina.scn.de(192.129.41.2) by proxy.scn.de via smap (V1.3) id sma001967; Thu Oct 12 13:33:10 1995 Received: (from uucp@localhost) by marina.scn.de (8.6.11/8.6.11) id NAA04033 for ; Thu, 12 Oct 1995 13:36:14 +0100 Received: from r316.m30x.nbg.scn.de(142.120.5.16) by marina.scn.de via smap (V1.3) id sma003865; Thu Oct 12 13:35:44 1995 Received: from msmgate.m30x.nbg.scn.de by r316.m30x.nbg.scn.de id aa25174; 12 Oct 95 13:34 MEZ Received: by MSMGATE.M30X.NBG.SCN.DE with Microsoft Mail id <307D7C33@MSMGATE.M30X.NBG.SCN.DE>; Thu, 12 Oct 95 13:36:03 PDT From: Haible_Juergen#Tel2743 To: DIY Subject: Re: OTA question Date: Thu, 12 Oct 95 13:35:00 PDT Message-Id: <307D7C33@MSMGATE.M30X.NBG.SCN.DE> Encoding: 30 TEXT X-Mailer: Microsoft Mail V3.0 Sender: owner-synth-diy@horus.sara.nl Precedence: bulk >> feeding a capacitor/resistor to ground and buffer it with an FET >> source follower. This will keep the circuit free of nasty opamp-style >> feedback. > > Nasty feedback? Interesting. Can you elaborate a little? Don has posted about this before, and he has some good points about it, IMO. Pumping signals thru dozens of nonlinear transistors, all in one heavy feedback loop, has its disadvantages. (Especially when the forward path is rather slow, due to the artificially reduced bandwidth, which is necessary for stable unity gain applications.) I tend to go for discrete circuits (and *local* feedback) more and more. For audio paths, that is. But sometimes I want my modules to be usable for both, audio signals and VC's. I built the mixers for my JH-3 Modular with discrete BJT's: The inputs are buffered by NPN emitter followers, then there is the pot for mixing between two sources, then the pot is buffered by a PNP to compensate for the voltage drop of the input buffer. Well, it doesn't compensate to 100%, so there is an offset trimmer as well, but at least the temperature drift is 1st-order compensated. This is quite usable for DC-coupled mixing applications, though there is a slight variation in offset voltage dependent on the pot's position. Guess using FETs instead of BJT would have been better for this - but then again the GS-voltage of FETs has a mouch wider spread than the BE of BJT's, so *selection* would have to be done ... ... it is *not* that easy to avoid this nasty overall feedback ! JH. From owner-synth-diy Thu Oct 12 12:59:09 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA116233; Thu, 12 Oct 1995 12:59:09 GMT Received: from localhost.sara.nl by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA24323; Thu, 12 Oct 1995 13:59:07 +0100 Message-Id: <9510121259.AA24323@horus.sara.nl> To: Synthesizer DIY list Subject: *NEW* Archived messages on WWW Date: Thu, 12 Oct 1995 13:59:06 +0100 From: Rick Jansen Sender: owner-synth-diy@horus.sara.nl Precedence: bulk The synth-diy mailing list WWW archive has been updated. All messages from the beginning till now are there: http://www.sara.nl/Rick.Jansen/Emusic/Synth-diy/Archive/Archive.html Rick Jansen __ rick@sara.nl http://www.sara.nl/Rick.Jansen _____________________________________________ S&H's a module and s&h's looking good From owner-synth-diy Thu Oct 12 16:02:30 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA91598; Thu, 12 Oct 1995 16:02:30 GMT Received: from netcom14.netcom.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA46274; Thu, 12 Oct 1995 17:02:27 +0100 Received: by netcom14.netcom.com (8.6.12/Netcom) id JAA02727; Thu, 12 Oct 1995 09:01:19 -0700 Date: Thu, 12 Oct 1995 09:01:19 -0700 Message-Id: <199510121601.JAA02727@netcom14.netcom.com> To: HJ2743@denbgm3xm.scnn1.msmgate.m30x.nbg.scn.de Cc: synth-diy@horus.sara.nl In-Reply-To: <307D5353@MSMGATE.M30X.NBG.SCN.DE> (message from Haible_Juergen#Tel2743 on Thu, 12 Oct 95 10:40:00 PDT) Subject: Re: OTA question Reply-To: don@till.com From: Don Tillman Organization: Don's house, Palo Alto, California Sender: owner-synth-diy@horus.sara.nl Precedence: bulk From: JH-3-Man Date: Thu, 12 Oct 95 10:40:00 PDT Thanks for the answer. I use the 13600/13700 almost every time, and I have used all three methods (discrete, follower, inverter) in different projects myself - but what I was really looking for was some theory about the two alternatives I named (in *some* applications the level shift of a discrete buffer is not that good). I was really asking about pro's and cons of the two named alternatives, and to make it easy I named a 3080. I might add that opamps I use to use the TL07x series. So given these to components (for what reason ever) - what would the pro's and con's for either configuration? (You certainly did ask about the pros and cons. I was just being lazy.) Okay, the OTA is performing the same function in both, except that, as you noted, in (1) the OTA output pin is seeing the output voltage and in (2) the OTA output pin is held at ground and the OTA is effectively cascoded. Obviously (2) is better in that the OTA output transistors get to deal with fewer nonlinearities, but I don't think that's an issue because those transistors are part of current mirrors, which are mighty linear. I can't say for sure without a complete chip schematic (or a microscope) but it's quite likely that the current mirrors are the more complex variety and are already cascoded. We're all pretty familiar with the vehavior of the opamp part of the circuit. So, I'm thinking it doesn't make much difference. -- Don From owner-synth-diy Thu Oct 12 18:25:50 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA83486; Thu, 12 Oct 1995 18:25:50 GMT Received: from netcom21.netcom.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA114200; Thu, 12 Oct 1995 19:25:47 +0100 Received: by netcom21.netcom.com (8.6.12/Netcom) id LAA26232; Thu, 12 Oct 1995 11:14:50 -0700 Date: Thu, 12 Oct 1995 11:14:50 -0700 Message-Id: <199510121814.LAA26232@netcom21.netcom.com> To: synth-diy@horus.sara.nl In-Reply-To: <307D7C33@MSMGATE.M30X.NBG.SCN.DE> (message from Haible_Juergen#Tel2743 on Thu, 12 Oct 1995 13:35:00 -0700 (PDT)) Subject: Re: OTA question Reply-To: don@till.com From: Don Tillman Organization: Don's house, Palo Alto, California Sender: owner-synth-diy@horus.sara.nl Precedence: bulk Date: Thu, 12 Oct 1995 13:35:00 -0700 (PDT) From: JH-3-Man > Nasty feedback? Interesting. Can you elaborate a little? Don has posted about this before, and he has some good points about it, IMO. Pumping signals thru dozens of nonlinear transistors, all in one heavy feedback loop, has its disadvantages. (Especially when the forward path is rather slow, due to the artificially reduced bandwidth, which is necessary for stable unity gain applications.) Exactly. Every circuit topology one can come up with has a different set of characteristic distortions, and it's a matter of personal aesthetics which annoy you or please you. Some distortions can be truly unbearable in the smallest quantities, and some others can be a lot of fun in comparatively larger quantities. It turns out that many of the pieces of electronic equipment that musicians drool over have only a small number of simple stages with little or no feedback. For example, many guitar amps (like the classic Vox and Fender models) have the signal going through roughly four simple tube stages. Same with tube hifi amps. The Moog Modular has very few opamps in the signal chain. The ARP Odyssey has none (except possibly the filter in the sealed box). Hammond organ, Mellotron, Clavinet, Wurlitzer piano... I'm talking the really warm juicey stuff here. On the other end of the scale, take something like those old Peavey mixers filled with 741s; they sound like crap. Or those Japanese hifi receivers from the 70's during the THD specmanship pissing contest. Or the Fender Utra Chorus guitar amp; this thing sounds horrible (personal opinion, of course) and look at the schematic and you'll see the signal going through 7 opamps, each with about 7 transistors in the signal path, plus a few discretes, so the signal goes through something like 54 transistors between the input and the output. Compare that to the Tweed Fender Bassman where the signal goes through four tube stages in series and you'll see what I mean. -- Don From owner-synth-diy Fri Oct 13 08:14:29 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA123988; Fri, 13 Oct 1995 08:14:29 GMT Received: from xgw1.pal.xgw.fi by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA25934; Fri, 13 Oct 1995 09:14:25 +0100 Received: from netcontrol.netcontrol.fi (netcontrol.netcontrol.fi [193.210.7.1]) by mail.xgw.fi (8.6.11/8.6.4) with ESMTP id LAA14508 for ; Fri, 13 Oct 1995 11:24:53 +0200 Received: (from jocke@localhost) by netcontrol.netcontrol.fi (8.6.11/8.6.9) id KAA31533; Fri, 13 Oct 1995 10:14:05 +0200 Date: Fri, 13 Oct 1995 10:14:04 +0200 (EET) From: Joachim Verghese To: Synth DIY Subject: Re: OTA question In-Reply-To: <199510121814.LAA26232@netcom21.netcom.com> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-synth-diy@horus.sara.nl Precedence: bulk Thanks, Don and Juergen, this is great information. I'll order a bunch of 3086s and JFETs very soon. :) -joachim PS Later ARP filters were based on the LM3900 quad norton amp and discrete gain stages. If I remember correctly, the LM3900 only has 4 or 5 transistors per amp, so I guess you could call it semi-discrete. From owner-synth-diy Fri Oct 13 08:42:17 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA55167; Fri, 13 Oct 1995 08:42:17 GMT Received: from ns.scn.de by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA96111; Fri, 13 Oct 1995 09:42:08 +0100 Received: (from uucp@localhost) by proxy.scn.de (8.6.11/8.6.11) id JAA27446 for ; Fri, 13 Oct 1995 09:38:51 +0100 Received: from marina.scn.de(192.129.41.2) by proxy.scn.de via smap (V1.3) id sma027400; Fri Oct 13 09:38:22 1995 Received: (from uucp@localhost) by marina.scn.de (8.6.11/8.6.11) id JAA05960 for ; Fri, 13 Oct 1995 09:41:27 +0100 Received: from r316.m30x.nbg.scn.de(142.120.5.16) by marina.scn.de via smap (V1.3) id sma005820; Fri Oct 13 09:40:43 1995 Received: from msmgate.m30x.nbg.scn.de by r316.m30x.nbg.scn.de id aa29183; 13 Oct 95 9:39 MEZ Received: by MSMGATE.M30X.NBG.SCN.DE with Microsoft Mail id <307E96A1@MSMGATE.M30X.NBG.SCN.DE>; Fri, 13 Oct 95 09:41:05 PDT From: Haible_Juergen#Tel2743 To: DIY Subject: Re: OTA question Date: Fri, 13 Oct 95 09:40:00 PDT Message-Id: <307E96A1@MSMGATE.M30X.NBG.SCN.DE> Encoding: 8 TEXT X-Mailer: Microsoft Mail V3.0 Sender: owner-synth-diy@horus.sara.nl Precedence: bulk > has very few opamps in the signal chain. The ARP Odyssey has none > (except possibly the filter in the sealed box). Hammond organ, Norton Amps, I think (current in, voltage out). JH. From owner-synth-diy Fri Oct 13 17:53:27 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA112035; Fri, 13 Oct 1995 17:53:27 GMT Received: from netcom21.netcom.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA106398; Fri, 13 Oct 1995 18:53:24 +0100 Received: by netcom21.netcom.com (8.6.12/Netcom) id KAA10518; Fri, 13 Oct 1995 10:32:53 -0700 Date: Fri, 13 Oct 1995 10:32:53 -0700 Message-Id: <199510131732.KAA10518@netcom21.netcom.com> To: synth-diy@horus.sara.nl In-Reply-To: (message from Joachim Verghese on Fri, 13 Oct 1995 10:14:04 +0200 (EET)) Subject: Re: OTA question Reply-To: don@till.com From: Don Tillman Organization: Don's house, Palo Alto, California Sender: owner-synth-diy@horus.sara.nl Precedence: bulk Date: Fri, 13 Oct 1995 10:14:04 +0200 (EET) From: Joachim Verghese Later ARP filters were based on the LM3900 quad norton amp and discrete gain stages. If I remember correctly, the LM3900 only has 4 or 5 transistors per amp, so I guess you could call it semi-discrete. I have no idea what's inside the Odyssey module, so now I'm incredibly curious; what's the circuit like? How on earth do they use an LM3900 in a VCF circuit? How did you get a schematic? -- Don From owner-synth-diy Sat Oct 14 07:18:54 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA124558; Sat, 14 Oct 1995 07:18:54 GMT Received: from beacon.synthcom.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA113800; Sat, 14 Oct 1995 08:18:49 +0100 Received: from synthcom.com (synthcom.com [198.145.98.1]) by synthcom.com (8.6.9/8.6.9) with SMTP id AAA20049 for ; Sat, 14 Oct 1995 00:15:36 -0700 Date: Sat, 14 Oct 1995 00:15:36 -0700 (PDT) From: "Jeffrey D.McEachin" To: synth-diy@horus.sara.nl Subject: Re: OTA question In-Reply-To: Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-synth-diy@horus.sara.nl Precedence: bulk On Fri, 13 Oct 1995, Don Tillman wrote: > I have no idea what's inside the Odyssey module, so now I'm incredibly > curious; what's the circuit like? How on earth do they use an LM3900 > in a VCF circuit? How did you get a schematic? You don't need a schematic to know about the LM3900's, as later modules were unpotted. I've got two broken ones sitting on my bench, awaiting the return of my Odyssey schematics so I can figure out the I/O. Module schematics for Arp stuff are hard to locate - Timothy Smith promised me a set when he got ahold of some, but I don't know if he ever got them. Phil Cirrocco (sp?) may have them as well. I'll let you know if I figure out the topology. JDM Synthcom Systems From owner-synth-diy Mon Oct 16 07:44:51 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA48372; Mon, 16 Oct 1995 07:44:51 GMT Received: from xgw1.pal.xgw.fi by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA91119; Mon, 16 Oct 1995 08:44:49 +0100 Received: from netcontrol.netcontrol.fi (netcontrol.netcontrol.fi [193.210.7.1]) by mail.xgw.fi (8.6.11/8.6.4) with ESMTP id JAA25397 for ; Mon, 16 Oct 1995 09:45:15 +0200 Received: (from jocke@localhost) by netcontrol.netcontrol.fi (8.6.11/8.6.9) id JAA02010; Mon, 16 Oct 1995 09:44:24 +0200 Date: Mon, 16 Oct 1995 09:44:24 +0200 (EET) From: Joachim Verghese To: Synth DIY Subject: ARP modules (was: OTA question) In-Reply-To: <199510131732.KAA10518@netcom21.netcom.com> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-synth-diy@horus.sara.nl Precedence: bulk On Fri, 13 Oct 1995, Don Tillman wrote: > I have no idea what's inside the Odyssey module, so now I'm incredibly > curious; what's the circuit like? How on earth do they use an LM3900 > in a VCF circuit? Basically, there are four similar stages, each consisiting of a dual PNP (apparently matched 3906s) gain stage which feeds a 3900 amp connected as a (Miller) integrator. > How did you get a schematic? Reverse engineering. In fact, I've got schematics of some other modules as well (incl. the 4034/4035 4-pole ladder filter), and I've been planning to put them in my WWW pages when I have time. -joachim From owner-synth-diy Mon Oct 16 09:25:51 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA126792; Mon, 16 Oct 1995 09:25:51 GMT Received: from ns.scn.de by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA96831; Mon, 16 Oct 1995 10:25:47 +0100 Received: (from uucp@localhost) by proxy.scn.de (8.6.11/8.6.11) id KAA04515 for ; Mon, 16 Oct 1995 10:22:26 +0100 Received: from marina.scn.de(192.129.41.2) by proxy.scn.de via smap (V1.3) id sma004455; Mon Oct 16 10:21:33 1995 Received: (from uucp@localhost) by marina.scn.de (8.6.11/8.6.11) id KAA11798 for ; Mon, 16 Oct 1995 10:24:43 +0100 Received: from r316.m30x.nbg.scn.de(142.120.5.16) by marina.scn.de via smap (V1.3) id sma011525; Mon Oct 16 10:24:03 1995 Received: from msmgate.m30x.nbg.scn.de by r316.m30x.nbg.scn.de id aa09669; 16 Oct 95 10:23 MEZ Received: by MSMGATE.M30X.NBG.SCN.DE with Microsoft Mail id <30829548@MSMGATE.M30X.NBG.SCN.DE>; Mon, 16 Oct 95 10:24:24 PDT From: Haible_Juergen#Tel2743 To: DIY Subject: Re: OTA question Date: Mon, 16 Oct 95 10:23:00 PDT Message-Id: <30829548@MSMGATE.M30X.NBG.SCN.DE> Encoding: 15 TEXT X-Mailer: Microsoft Mail V3.0 Sender: owner-synth-diy@horus.sara.nl Precedence: bulk > I have no idea what's inside the Odyssey module, so now I'm incredibly > curious; what's the circuit like? How on earth do they use an LM3900 > in a VCF circuit? How did you get a schematic? The ARP filters are very interesting designs. Not the first ones: just a Moog ladder built of arrays. But the later ones use discrete PNP pairs as variable gm stages, and the Norton Opamps act as differential current-to-voltage converters. Basically, it's a similar thing as those OTA-circuits, only that the OTA has the diff pair inside the chip, and not the buffer, and here it's just the opposite. And a PNP input stage ... and some additional reference voltage/current paths are required externally. JH. From owner-synth-diy Mon Oct 16 09:33:56 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA72500; Mon, 16 Oct 1995 09:33:56 GMT Received: from ns.scn.de by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA51236; Mon, 16 Oct 1995 10:33:46 +0100 Received: (from uucp@localhost) by proxy.scn.de (8.6.11/8.6.11) id KAA05347; Mon, 16 Oct 1995 10:30:22 +0100 Received: from marina.scn.de(192.129.41.2) by proxy.scn.de via smap (V1.3) id sma005326; Mon Oct 16 10:30:12 1995 Received: (from uucp@localhost) by marina.scn.de (8.6.11/8.6.11) id KAA13749; Mon, 16 Oct 1995 10:33:21 +0100 Received: from r316.m30x.nbg.scn.de(142.120.5.16) by marina.scn.de via smap (V1.3) id sma013609; Mon Oct 16 10:32:47 1995 Received: from msmgate.m30x.nbg.scn.de by r316.m30x.nbg.scn.de id aa09699; 16 Oct 95 10:31 MEZ Received: by MSMGATE.M30X.NBG.SCN.DE with Microsoft Mail id <3082974E@MSMGATE.M30X.NBG.SCN.DE>; Mon, 16 Oct 95 10:33:02 PDT From: Haible_Juergen#Tel2743 To: DIY , till Subject: FW: OTA question Date: Mon, 16 Oct 95 10:32:00 PDT Message-Id: <3082974E@MSMGATE.M30X.NBG.SCN.DE> Encoding: 10 TEXT X-Mailer: Microsoft Mail V3.0 Sender: owner-synth-diy@horus.sara.nl Precedence: bulk > > and here it's just the opposite. And a PNP input stage ... and some > additional reference voltage/current paths are required externally. Sorry to follow up my own posting, but I'm not absolutely sure about the gm pairs being PNP; might also be NPN plus an offset current, so don't sue me (;->) - have to look again at home! JH. From owner-synth-diy Mon Oct 16 09:59:47 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA99577; Mon, 16 Oct 1995 09:59:47 GMT Received: from ns.scn.de by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA97005; Mon, 16 Oct 1995 10:59:44 +0100 Received: (from uucp@localhost) by proxy.scn.de (8.6.11/8.6.11) id KAA07685 for ; Mon, 16 Oct 1995 10:56:25 +0100 Received: from marina.scn.de(192.129.41.2) by proxy.scn.de via smap (V1.3) id sma007649; Mon Oct 16 10:55:58 1995 Received: (from uucp@localhost) by marina.scn.de (8.6.11/8.6.11) id KAA18937 for ; Mon, 16 Oct 1995 10:59:07 +0100 Received: from r316.m30x.nbg.scn.de(142.120.5.16) by marina.scn.de via smap (V1.3) id sma018729; Mon Oct 16 10:58:13 1995 Received: from msmgate.m30x.nbg.scn.de by r316.m30x.nbg.scn.de id aa09816; 16 Oct 95 10:57 MEZ Received: by MSMGATE.M30X.NBG.SCN.DE with Microsoft Mail id <30829D4D@MSMGATE.M30X.NBG.SCN.DE>; Mon, 16 Oct 95 10:58:37 PDT From: Haible_Juergen#Tel2743 To: DIY Subject: new module Date: Mon, 16 Oct 95 10:58:00 PDT Message-Id: <30829D4D@MSMGATE.M30X.NBG.SCN.DE> Encoding: 31 TEXT X-Mailer: Microsoft Mail V3.0 Sender: owner-synth-diy@horus.sara.nl Precedence: bulk Hi, last night I finished the PCB design of my next module. It contains the Analogue Shift Register (I posted about this before). As the ASR just has 5 jacks on the front panel, but it needs more than half of a 10cm*16cm pcb, I decided to add some other functions to that module. I decided to include two voltage controllable 2-stage-envelopes. The first one is an AD-type, which can be switched from AD to LFO and REPEAT. LFO means that it runs free; REPEAT means that it cycles as long as there is a gate (I.e. gated lfo). I used a SSM2056 with R and S inputs at GND, and Gate at VCC. It is just controlled by the trigger input. A comparator measures when the output goes to zero (the 2056's asymptode is some mV below zero!), to enable the cycle features. There is a knob for Attack and Decay, plus a jack and a 3-way switch to choose modulation of attack and/or decay time. The second one is an AR-type, which can be switched from AR to SLEW. The whole thing really is a VC slew limiter, built around a LM13700. If You switch it to AR, the input is routed thru a schmitt trigger to form a 0V/+5V gate out of any input signal. There is a knob for Attack and Release, plus a jack and a 3-way switch to choose modulation of attack and/or release time. As the pcb was very highly populated now (my most dense pcb so far), I filled the rest of the front panel with Multiples (2x4 jacks). JH. From owner-synth-diy Mon Oct 16 17:13:40 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA112588; Mon, 16 Oct 1995 17:13:40 GMT Received: from safety.worldcom.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA62661; Mon, 16 Oct 1995 18:13:36 +0100 Received: (from smtp@localhost) by safety.worldcom.com (8.7.1/8.6.9) id LAA13932 for ; Mon, 16 Oct 1995 11:43:37 -0500 (CDT) Received: from worldcom-45.worldcom.com(198.64.193.76) by safety.worldcom.com via smap (V1.3) id sma013863; Mon Oct 16 11:43:00 1995 Received: by worldcom-45.worldcom.com (IBM OS/2 SENDMAIL VERSION 1.3.14/3.3) id AA7621; Mon, 16 Oct 95 11:37:22 -0400 Message-Id: <9510161537.AA7621@worldcom-45.worldcom.com> Received: from worldcom with "Lotus Notes Mail Gateway for SMTP" id 5CE4509BD0239A6786256257005983DA; Mon, 16 Oct 95 11:37:21 To: DIY From: Christopher List Date: 16 Oct 95 10:32:34 Subject: Where can I get a little pot... Mime-Version: 1.0 Content-Type: Text/Plain Sender: owner-synth-diy@horus.sara.nl Precedence: bulk Potentiometer that is... (sorry, but I couldn't <> -ug) I'm looking for mini-size pots (like the 1/2" diameter ones) with knurled posts. I've got all these catalogs (Newark, Mouser, Digi-Key) and none of them have these - yet I find them in all kinds of equiptment. I need linear and audio taper (Mouser has linear taper ones - though the posts are a little long). Anybody know of a good source for these? Do places like Newark stock a lot of stuff that's not in the catalog? Is there any reason why I shouldn't use the mini-pots? - I need the front-panel real estate. I know this is kind of a lame question, but I'm starting to get frustrated. -Thanks, Chris From owner-synth-diy Sun Oct 22 16:14:53 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA41296; Sun, 22 Oct 1995 16:14:53 GMT Received: from ix2.ix.netcom.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA128329; Sun, 22 Oct 1995 17:14:50 +0100 Received: from by ix2.ix.netcom.com (8.7.1/SMI-4.1/Netcom) id JAA01678; Sun, 22 Oct 1995 09:15:37 -0700 (PDT) Date: Sun, 22 Oct 1995 09:15:37 -0700 (PDT) Message-Id: <199510221615.JAA01678@ix2.ix.netcom.com> From: chordman@ix.netcom.com (Scott Gravenhorst, Synthaholic) Subject: test - ignore To: synth-diy@horus.sara.nl Sender: owner-synth-diy@horus.sara.nl Precedence: bulk sorry. -- -- Scott G., Synthaholic There is no 12 step program for synthaholics. Thank your Superior Being. From owner-synth-diy Sun Oct 22 21:38:07 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA86269; Sun, 22 Oct 1995 21:38:07 GMT Received: from ix4.ix.netcom.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA78323; Sun, 22 Oct 1995 22:38:04 +0100 Received: from by ix4.ix.netcom.com (8.7.1/SMI-4.1/Netcom) id OAA11107; Sun, 22 Oct 1995 14:38:00 -0700 (PDT) Date: Sun, 22 Oct 1995 14:38:00 -0700 (PDT) Message-Id: <199510222138.OAA11107@ix4.ix.netcom.com> From: chordman@ix.netcom.com (Scott Gravenhorst ) Subject: VC pots To: synth-diy@horus.sara.nl Sender: owner-synth-diy@horus.sara.nl Precedence: bulk I have seen circuits for 'voltage controlled resistors' that are really an MOS analog switch whose control input is driven by a pulsewidth modulated constant frequency oscillator. A voltage divider circuit should just be two analog switches, with one common connection, where one uses the pulse output of the oscillator for control and the other uses the inversion of the pulse output. Has anyone here tried to use this method to add voltage control to a circuit (to do what the pot does)? From owner-synth-diy Mon Oct 23 09:22:22 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA88637; Mon, 23 Oct 1995 09:22:22 GMT Received: from localhost.sara.nl by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA73014; Mon, 23 Oct 1995 10:22:19 +0100 Message-Id: <9510230922.AA73014@horus.sara.nl> To: chordman@ix.netcom.com (Scott Gravenhorst ), Synthesizer DIY list Subject: Re: VC pots In-Reply-To: Your message of Sun, 22 Oct 1995 14:38:00 MET. <199510222138.OAA11107@ix4.ix.netcom.com> Date: Mon, 23 Oct 1995 10:22:19 +0100 From: Rick Jansen Sender: owner-synth-diy@horus.sara.nl Precedence: bulk In message <199510222138.OAA11107@ix4.ix.netcom.com> you write: > I have seen circuits for 'voltage controlled resistors' that are really > an MOS analog switch whose control input is driven by a pulsewidth > modulated constant frequency oscillator. > > A voltage divider circuit should just be two analog switches, with one > common connection, where one uses the pulse output of the oscillator > for control and the other uses the inversion of the pulse output. > > Has anyone here tried to use this method to add voltage control to a > circuit (to do what the pot does)? You can build VC resistors with OTA's too. National Semiconductor's data sheets for the 13600 show a circuit. Another method is to use a JFET. Rick Jansen __ rick@sara.nl http://www.sara.nl/Rick.Jansen _____________________________________________ S&H's a module and s&h's looking good From owner-synth-diy Mon Oct 23 13:04:25 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA159352; Mon, 23 Oct 1995 13:04:25 GMT Received: from ns.scn.de by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA167479; Mon, 23 Oct 1995 14:04:16 +0100 Received: (from uucp@localhost) by proxy.scn.de (8.6.11/8.6.11) id OAA16619; Mon, 23 Oct 1995 14:00:44 +0100 Received: from marina.scn.de(192.129.41.2) by proxy.scn.de via smap (V1.3) id sma016442; Mon Oct 23 13:59:33 1995 Received: (from uucp@localhost) by marina.scn.de (8.6.11/8.6.11) id OAA17165; Mon, 23 Oct 1995 14:02:47 +0100 Received: from r316.m30x.nbg.scn.de(142.120.5.16) by marina.scn.de via smap (V1.3) id sma016998; Mon Oct 23 14:02:05 1995 Received: from msmgate.m30x.nbg.scn.de by r316.m30x.nbg.scn.de id aa09332; 23 Oct 95 14:00 MEZ Received: by MSMGATE.M30X.NBG.SCN.DE with Microsoft Mail id <308C02DA@MSMGATE.M30X.NBG.SCN.DE>; Mon, 23 Oct 95 14:02:18 PDT From: Haible_Juergen#Tel2743 To: analogue , bode , DIY Subject: test, please ignore Date: Mon, 23 Oct 95 14:01:00 PDT Message-Id: <308C02DA@MSMGATE.M30X.NBG.SCN.DE> Encoding: 2 TEXT X-Mailer: Microsoft Mail V3.0 Sender: owner-synth-diy@horus.sara.nl Precedence: bulk ===!=== From owner-synth-diy Mon Oct 23 15:11:15 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA77403; Mon, 23 Oct 1995 15:11:15 GMT Received: from ns.scn.de by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA161349; Mon, 23 Oct 1995 16:11:05 +0100 Received: (from uucp@localhost) by proxy.scn.de (8.6.11/8.6.11) id QAA00591; Mon, 23 Oct 1995 16:07:24 +0100 Received: from marina.scn.de(192.129.41.2) by proxy.scn.de via smap (V1.3) id sma000525; Mon Oct 23 16:07:04 1995 Received: (from uucp@localhost) by marina.scn.de (8.6.11/8.6.11) id QAA12707; Mon, 23 Oct 1995 16:10:17 +0100 Received: from r316.m30x.nbg.scn.de(142.120.5.16) by marina.scn.de via smap (V1.3) id sma012516; Mon Oct 23 16:09:28 1995 Received: from msmgate.m30x.nbg.scn.de by r316.m30x.nbg.scn.de id aa10028; 23 Oct 95 16:08 MEZ Received: by MSMGATE.M30X.NBG.SCN.DE with Microsoft Mail id <308C20BD@MSMGATE.M30X.NBG.SCN.DE>; Mon, 23 Oct 95 16:09:49 PDT From: Haible_Juergen#Tel2743 To: analogue , bode , DIY Subject: new module idea Date: Mon, 23 Oct 95 16:08:00 PDT Message-Id: <308C20BD@MSMGATE.M30X.NBG.SCN.DE> Encoding: 21 TEXT X-Mailer: Microsoft Mail V3.0 Sender: owner-synth-diy@horus.sara.nl Precedence: bulk Hi! For all those who are interested in the progress of my homebuilt modular JH-3, here is an idea for one of my next modules, the "Morphing Programmer". It's inspired by sequencers/programmers/touch-keyboards. It will have 3 rows of about 6 potentiometers each, and an output jack for each of the 6 coloumns. So You have 3 sets of 6 control voltages to switch between. But I won't do a simple switching, but really a crossfade. The circuit should be dead easy: Just a built-in slew limiter for each coloumn, with a common lag time control knob (and CV input). Connecting the 6 CV's to different points like VC-ADSR time, VC-resonance and stuff, I hope to get some really interesting analogue Morphing sounds. With a variable pulse width clock signal at the switch inputs I could not only morph in time, but also with a variable CV (i.e. the CV which is controlling the PW of the clock signal). JH. From owner-synth-diy Mon Oct 23 17:02:45 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA180478; Mon, 23 Oct 1995 17:02:45 GMT Received: from qed.cloverleaf.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA63685; Mon, 23 Oct 1995 18:02:34 +0100 Received: from [205.153.188.105] (stanton-1-5.cloverleaf.com [205.153.188.105]) by qed.cloverleaf.com (8.6.5/8.6.5) with SMTP id JAA27912 for ; Mon, 23 Oct 1995 09:57:10 -0700 X-Sender: haines@mail.quick.net Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Mon, 23 Oct 1995 10:09:15 -0800 To: synth-diy@horus.sara.nl From: haines@quick.net (Matt Haines) Subject: Re: new module idea Sender: owner-synth-diy@horus.sara.nl Precedence: bulk >So You have 3 sets of 6 control voltages to switch between. >But I won't do a simple switching, but really a crossfade. >The circuit should be dead easy: Just a built-in slew limiter for >each coloumn, with a common lag time control knob (and >CV input). Connecting the 6 CV's to different points like VC-ADSR >time, VC-resonance and stuff, I hope to get some really interesting >analogue Morphing sounds. >With a variable pulse width clock signal at the switch inputs >I could not only morph in time, but also with a variable CV >(i.e. the CV which is controlling the PW of the clock signal). > >JH. Why not go all the way and have a seperate lag time for each column, so you could set everything independently? I was just dreaming of a sequencer that would have independent portamento rates for each 'note' the other day. Matt Haines haines@quick.net \co/ntrol-X \to /\abort / \transmission. control-X sez: "Don't Eat Plants! Plants are our friends!" From owner-synth-diy Tue Oct 24 13:46:28 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA38084; Tue, 24 Oct 1995 13:46:28 GMT Received: from ns.scn.de by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA181157; Tue, 24 Oct 1995 14:46:21 +0100 Received: (from uucp@localhost) by proxy.scn.de (8.6.11/8.6.11) id OAA18712 for ; Tue, 24 Oct 1995 14:42:50 +0100 Received: from marina.scn.de(192.129.41.2) by proxy.scn.de via smap (V1.3) id sma018585; Tue Oct 24 14:41:43 1995 Received: (from uucp@localhost) by marina.scn.de (8.6.11/8.6.11) id OAA04558 for ; Tue, 24 Oct 1995 14:44:58 +0100 Received: from r316.m30x.nbg.scn.de(142.120.5.16) by marina.scn.de via smap (V1.3) id sma004397; Tue Oct 24 14:44:01 1995 Received: by r316.m30x.nbg.scn.de id ab14163; 24 Oct 95 15:42 MESZ Received: from msmgate.m30x.nbg.scn.de by r316.m30x.nbg.scn.de id aa14039; 24 Oct 95 14:34 MEZ Received: by MSMGATE.M30X.NBG.SCN.DE with Microsoft Mail id <308D5C3A@MSMGATE.M30X.NBG.SCN.DE>; Tue, 24 Oct 95 14:35:54 PDT From: Haible_Juergen#Tel2743 To: DIY Subject: Re: new module idea Date: Tue, 24 Oct 95 09:45:00 PDT Message-Id: <308D5C3A@MSMGATE.M30X.NBG.SCN.DE> Encoding: 18 TEXT X-Mailer: Microsoft Mail V3.0 Sender: owner-synth-diy@horus.sara.nl Precedence: bulk > Why not go all the way and have a seperate lag time for each column, so you > could set everything independently? That's a goog idea as well (easy to realize with individual portamento circuits), but that's exactly what I did *not* want to do. I will have a single knob to change the morph rate for all CV's. > I was just dreaming of a sequencer that > would have independent portamento rates for each 'note' the other day. No problem. Take a voltage controlled Slew Limiter or something similar, connect one row of Your sequencer to the signal input and another row to the time-CV input of the Slew Limiter. JH. From owner-synth-diy Tue Oct 24 19:31:19 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA96290; Tue, 24 Oct 1995 19:31:19 GMT Received: from desiree.teleport.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA156431; Tue, 24 Oct 1995 20:31:13 +0100 Received: from kelly.teleport.com (mr808@kelly.teleport.com [192.108.254.10]) by desiree.teleport.com (8.6.12/8.6.9) with ESMTP id MAA15371 for ; Tue, 24 Oct 1995 12:31:11 -0700 Date: Tue, 24 Oct 1995 12:31:09 -0700 (PDT) From: Fucking GOD of Roland To: synth-diy@horus.sara.nl Subject: RE: VC pots In-Reply-To: <199510241912.MAA07572@desiree.teleport.com> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-synth-diy@horus.sara.nl Precedence: bulk > > Date: Mon, 23 Oct 1995 10:22:19 +0100 > > From: Rick Jansen > > > You can build VC resistors with OTA's too. National Semiconductor's > > data sheets for the 13600 show a circuit. Another method is to use > > a JFET. > I thought that JFETs had problems w/ control signal feedthru, making them undesireable for use where you're attenuating an audio signal, such as resonance. Maybe someone could clarify this? I would dearly love to see a comparison between or discussion about different types of VCAs - JFETs, OTAs, dedicated VCA circuits, motorized Potentiometers, DAC R2R ladders, etc. comparing cost/complexity to performance. 808 From owner-synth-diy Tue Oct 24 21:21:28 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA52629; Tue, 24 Oct 1995 21:21:28 GMT Received: from qed.cloverleaf.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA131204; Tue, 24 Oct 1995 22:21:23 +0100 Received: from [205.153.188.102] (stanton-1-2.cloverleaf.com [205.153.188.102]) by qed.cloverleaf.com (8.6.5/8.6.5) with SMTP id OAA24217 for ; Tue, 24 Oct 1995 14:14:28 -0700 X-Sender: haines@mail.quick.net Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Tue, 24 Oct 1995 14:28:10 -0800 To: synth-diy@horus.sara.nl From: haines@quick.net (Matt Haines) Subject: Re: new module idea Sender: owner-synth-diy@horus.sara.nl Precedence: bulk >> I was just dreaming of a sequencer that >> would have independent portamento rates for each 'note' the other day. > >No problem. Take a voltage controlled Slew Limiter or something >similar, connect one row of Your sequencer to the signal input and another >row to the time-CV input of the Slew Limiter. > OK, now I've got to find a darn sequencer.... :) But I see what you're saying...you don't need multiple slew-limiters if it's v-controlled, as you just use a row of voltages to control it. Hmm. Interesting. Matt Haines haines@quick.net \co/ntrol-X \to /\abort / \transmission. control-X sez: enjoy the system. From owner-synth-diy Tue Oct 24 22:09:50 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA155181; Tue, 24 Oct 1995 22:09:50 GMT Received: from scylla.charybdis.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA108066; Tue, 24 Oct 1995 23:09:44 +0100 Received: from hyperion.charybdis.com (hyperion.charybdis.com [204.157.166.212]) by scylla.charybdis.com (8.6.12/8.6.9) with SMTP id RAA01118 for ; Tue, 24 Oct 1995 17:08:51 -0500 Received: by hyperion.charybdis.com with Microsoft Mail id <01BAA232.D26970E0@hyperion.charybdis.com>; Tue, 24 Oct 1995 17:04:46 -0500 Message-Id: <01BAA232.D26970E0@hyperion.charybdis.com> From: Dan Higdon To: "'synth-diy@horus.sara.nl'" Subject: RE: new module idea Date: Tue, 24 Oct 1995 17:04:45 -0500 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: owner-synth-diy@horus.sara.nl Precedence: bulk Matt Haines[SMTP:haines@quick.net] writes: > OK, now I've got to find a darn sequencer.... :) But I see what you're > saying...you don't need multiple slew-limiters if it's v-controlled, as you > just use a row of voltages to control it. Hmm. Interesting. > Matt Haines haines@quick.net Were you serious about needing a sequencer? :-) The Terrence Thomas book has a sequencer schematic in it. It's based on a decade counter (4010?). The particular counter used can apparently generate the voltages needed from its output pins, so long as you give it an appropriate supply voltage (+10v or +15v, most likely). It then just uses a pot wired as a voltage divider, one for each output * one per row. His example had three rows of ten, and LEDs to show which stage is active. I can try to scan the schematic, if anyone is interested. Like the rest of the stuff in his book, it assumes +15v control voltages, and a +15v power supply (no -15v!). Oh yeah, and you have to supply a pulse source as well. The same book has a VC pulse generator in it; I could scan that as well. Someone around here built one a while back, and said that it worked well. As I've only built an LFO so far, it seemed a little pre-mature to be building a sequencer for myself.... :-) Dan Higdon (hdan@charybdis.com) From owner-synth-diy Wed Oct 25 09:44:46 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA32048; Wed, 25 Oct 1995 09:44:46 GMT Received: from ns.scn.de by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA98339; Wed, 25 Oct 1995 10:44:37 +0100 Received: (from uucp@localhost) by proxy.scn.de (8.6.11/8.6.11) id KAA10070; Wed, 25 Oct 1995 10:41:12 +0100 Received: from marina.scn.de(192.129.41.2) by proxy.scn.de via smap (V1.3) id sma009936; Wed Oct 25 10:40:04 1995 Received: (from uucp@localhost) by marina.scn.de (8.6.11/8.6.11) id KAA15960; Wed, 25 Oct 1995 10:43:19 +0100 Received: from r316.m30x.nbg.scn.de(142.120.5.16) by marina.scn.de via smap (V1.3) id sma015794; Wed Oct 25 10:42:32 1995 Received: from msmgate.m30x.nbg.scn.de by r316.m30x.nbg.scn.de id aa18033; 25 Oct 95 10:41 MEZ Received: by MSMGATE.M30X.NBG.SCN.DE with Microsoft Mail id <308E7719@MSMGATE.M30X.NBG.SCN.DE>; Wed, 25 Oct 95 10:42:49 PDT From: Haible_Juergen#Tel2743 To: SuperBad MoFo , DIY Subject: AW: VC pots Date: Wed, 25 Oct 95 10:42:00 PDT Message-Id: <308E7719@MSMGATE.M30X.NBG.SCN.DE> Encoding: 65 TEXT X-Mailer: Microsoft Mail V3.0 Sender: owner-synth-diy@horus.sara.nl Precedence: bulk > I would dearly love to see a comparison between or discussion about >different types of VCAs - JFETs, OTAs, dedicated VCA circuits, motorized >Potentiometers, DAC R2R ladders, etc. comparing cost/complexity to >performance. JFETs: pro's: nonlinear (quadratic?) CV response is often desirable (in compressors and in phasers) small component, easy to layout the pcb con's: very small voltages needed to prevent distortion => unually rather noisy circuits (at least together with cheap opamps as active elements) OTAs: pro's: cheap, easy to use, kind of "standard" in synths con's: SNR limited to about 65 ... 75 dB LDR + LED: pro's: very good SNR con's: very slow NTC + heater: (just for the record. Don't know much about that, only that this combination is quite common in ALC circuits of commercial telecomunication systems) motorized pots: pro's: very good SNR con's: very slow, very large, very expensive special VCA IC's: pro's: good SNR con's: expensive and sometimes hard to get DAC's, programmable pot ICs etc: pro's: good computer interface con's: staircase stepping The list is not complete, I know. Maybe it's a start for comments / additions, however. And don't forget, sometimes the "con's" are a feature: I *love* the distortion of my overdriven FET-based cheap Phaser pedal! JH. From owner-synth-diy Wed Oct 25 22:44:26 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA93298; Wed, 25 Oct 1995 22:44:26 GMT Received: from fibermux.fibermux.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA81658; Wed, 25 Oct 1995 23:42:45 +0100 Received: from ccrelay.fibermux.com by fibermux.fibermux.com (4.1/SMI-4.1) id AA16697; Wed, 25 Oct 95 15:44:35 PDT Received: from cc:Mail by ccrelay.fibermux.com id AA814661114; Wed, 25 Oct 95 15:39:55 PDT Date: Wed, 25 Oct 95 15:39:55 PDT From: gstopp@fibermux.com Encoding: 30 Text Message-Id: <9509258146.AA814661114@ccrelay.fibermux.com> To: synth-diy@horus.sara.nl Subject: Re: AW: easy self made analog sequencer Sender: owner-synth-diy@horus.sara.nl Precedence: bulk Maybe we should consider the line of analog switches from Maxim. They have 16-to-1 muxes, 8-to-1 muxes, quads, duals, etc. Some have on resistances below 35 ohms, all are below 100 ohms. They run off of +10 to +30 volts or +/- 4.5 to +/- 20 volts, and rail-to-rail signals are allowed. They also have an ESD tolerance of >2000 volts. The control inputs are TTL and CMOS compatible even when running off of bipolar supplies. - Gene ______________________________ Reply Separator _________________________________ Subject: AW: easy self made analog sequencer Author: Haible_Juergen#Tel2743 at ccrelayout Date: 10/23/95 3:04 PM > A minus ? Take care of the power supply range of the CMOS IC's ! They die of voltages above 18V (the usual "analogue" range is +/-15V, i.e. 30V !!!) If You want to switch CV's, a quite large system of scale- down-and-restore amps plus an auxiliary +/- 7.5V supply is the way to go ... (Too compley, IMO. I'd rather use discrete FETs) JH. From owner-synth-diy Wed Oct 25 23:52:49 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA51142; Wed, 25 Oct 1995 23:52:49 GMT Received: from wdus06.wdc.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA41106; Thu, 26 Oct 1995 00:51:56 +0100 Message-Id: <9510252351.AA41106@horus.sara.nl> Received: with SMTP-MR; Wed, 25 Oct 1995 16:49 PST Date: Thu, 26 Oct 1995 00:47 PST From: Barry Klein 714-932-7493 Subject: analog switches To: SYNTH-DIY@horus.sara.nl Content-Type: TEXT Posting-Date: Thu, 26 Oct 1995 00:48 PST Importance: normal Priority: non-urgent X-Hop-Count: 1 A1-Type: MAIL Sender: owner-synth-diy@horus.sara.nl Precedence: bulk CMOS analog switches are used in many commercial synths, from the Prophet 5 to the K2000. They are a factor of 10 cheaper than the Maxim analog switches and work fine. You can also use the 4007 discretely, placing one fet on the "-" input and another in the feedback to compensate. I've got the circuit somewhere....... klein_b@a1.wdc.com From owner-synth-diy Thu Oct 26 01:53:31 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA47371; Thu, 26 Oct 1995 01:53:31 GMT Received: from mail1.wolfe.net by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA84997; Thu, 26 Oct 1995 02:53:23 +0100 Received: from gonzo.wolfe.net (ms20@gonzo.wolfe.net [204.157.98.2]) by wolfe.net (8.7/8.7) with SMTP id SAA05586 for ; Wed, 25 Oct 1995 18:57:42 -0700 (PDT) Date: Wed, 25 Oct 1995 18:52:00 -0700 (PDT) From: Fractals You Can Eat X-Sender: ms20@gonzo.wolfe.net To: synth-diy Subject: (fwd) Moog Music Announces 1996 Product Line (fwd) Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-synth-diy@horus.sara.nl Precedence: bulk Found this on usenet. Thought somebody on this list might enjoy this: October 23, 1995 Moog Music Inc. / 1996 Product Line These days it seems more and more companies want to tell you about their classic sounds, analog feel, or vinatge warmth... If these descriptions are exactly what you want in a synthesizer, then in 1996, a new product line from a new company will delight and surprise you. Moog Music is pleased to announce a new product line combining craftmanship and strict quality control to bring you the finest sounding modular systems and synthesizers available. The 1996 product line will fully intergrate with all existing Moog systems. We welcome any questions, comments or opinions you may have. 9500 Series Modular Synthesizers: 9500 Series modules combine the latest methods for stability and tuning precision without sacrificing warmth and color. Every knob, switch and panel indication on the 9500 series has been carefully thought out to make your creative process fast, efficient and rewarding. 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They are the System I and the System IV. Both systems are housed in 9800R rack panels that can be installed in standard rolling racks for your convience. Please write for individual specifications. MDC-4: 4 Channel MIDI to CV Convertor. Easily upgraded to your choice of 8 or 16 cahnnels.Features include MIDI In, Out, Thru, DIN Sync out, DCB Connection, and individual LFOs per channel. Projected Summer 1996. 4500 Series Synthesizer: A portable version combing the best qualities of our 9500 series modular systems, hard wired and patchable with complete MIDI control. Projected Summer 1996. All Prices To Be Announced. Please write for our upcoming product catalog, or for individual specifications. Include mailing address and phone number. Please email to 76512.227@compuserve.com Moog Music Inc. 10050 Montgomery Road Box 313 Dept. 23 Cincinnati, OH 45242 Copyright 1995 - Moog Music Incoporated - A Division Of Echo Park Music, Inc. Moog is a trademark of Moog Music Inc. From owner-synth-diy Thu Oct 26 02:27:19 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA77828; Thu, 26 Oct 1995 02:27:19 GMT Received: from mail1.wolfe.net by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA81659; Thu, 26 Oct 1995 03:27:16 +0100 Received: from gonzo.wolfe.net (ms20@gonzo.wolfe.net [204.157.98.2]) by wolfe.net (8.7/8.7) with SMTP id TAA07347 for ; Wed, 25 Oct 1995 19:31:41 -0700 (PDT) Date: Wed, 25 Oct 1995 19:25:58 -0700 (PDT) From: Fractals You Can Eat X-Sender: ms20@gonzo.wolfe.net To: synth-diy Subject: CV Crossfader? Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-synth-diy@horus.sara.nl Precedence: bulk Does anyone have a good schematic for a CV crossfader? Seems like it would be similar to a CV'd mixer, but wouldn't you need non-linear control? R> From owner-synth-diy Thu Oct 26 06:29:20 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA112585; Thu, 26 Oct 1995 06:29:20 GMT Received: from netcom10.netcom.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA87236; Thu, 26 Oct 1995 07:29:18 +0100 Received: by netcom10.netcom.com (8.6.12/Netcom) id XAA27530; Wed, 25 Oct 1995 23:27:53 -0700 Date: Wed, 25 Oct 1995 23:27:53 -0700 Message-Id: <199510260627.XAA27530@netcom10.netcom.com> To: synth-diy@horus.sara.nl In-Reply-To: <308E7719@MSMGATE.M30X.NBG.SCN.DE> (message from Haible_Juergen#Tel2743 on Wed, 25 Oct 1995 10:42:00 -0700 (PDT)) Subject: Re: AW: VC pots Reply-To: don@till.com From: Don Tillman Organization: Don's house, Palo Alto, California Sender: owner-synth-diy@horus.sara.nl Precedence: bulk Date: Wed, 25 Oct 1995 10:42:00 -0700 (PDT) From: Haible_Juergen JFETs: pro's: nonlinear (quadratic?) CV response is often desirable (in compressors and in phasers) small component, easy to layout the pcb con's: very small voltages needed to prevent distortion => unually rather noisy circuits (at least together with cheap opamps as active elements) The response isn't a quadratic curve, but I don't know that it's anything especially useful. The signal voltage doesn't have to be all that small, 0.5 volt or so. I think the noise level is really quite low. OTAs: pro's: cheap, easy to use, kind of "standard" in synths con's: SNR limited to about 65 ... 75 dB Now *these* need a small signal voltage, .05 volt or so. The big feature is very accurate linear or exponential control over a very wide range (several decades). This is usually the big determining issue. Some OTAs can be very low noise. LDR + LED: pro's: very good SNR con's: very slow Not that slow, some LDRs can move pretty quickly. NTC + heater: (just for the record. Don't know much about that, only that this combination is quite common in ALC circuits of commercial telecomunication systems) motorized pots: pro's: very good SNR con's: very slow, very large, very expensive Anything with motors is *cool*. special VCA IC's: pro's: good SNR con's: expensive and sometimes hard to get I'm pretty sure all special VCA chips are in fact OTAs. DAC's, programmable pot ICs etc: pro's: good computer interface con's: staircase stepping -- Don From owner-synth-diy Thu Oct 26 09:09:03 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA15890; Thu, 26 Oct 1995 09:09:03 GMT Received: from ns.scn.de by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA28401; Thu, 26 Oct 1995 10:08:43 +0100 Received: (from uucp@localhost) by proxy.scn.de (8.6.11/8.6.11) id KAA26785; Thu, 26 Oct 1995 10:04:25 +0100 Received: from marina.scn.de(192.129.41.2) by proxy.scn.de via smap (V1.3) id sma026700; Thu Oct 26 10:03:36 1995 Received: (from uucp@localhost) by marina.scn.de (8.6.11/8.6.11) id KAA14188; Thu, 26 Oct 1995 10:06:53 +0100 Received: from r316.m30x.nbg.scn.de(142.120.5.16) by marina.scn.de via smap (V1.3) id sma014103; Thu Oct 26 10:06:30 1995 Received: from msmgate.m30x.nbg.scn.de by r316.m30x.nbg.scn.de id aa23563; 26 Oct 95 10:04 MEZ Received: by MSMGATE.M30X.NBG.SCN.DE with Microsoft Mail id <308FC013@MSMGATE.M30X.NBG.SCN.DE>; Thu, 26 Oct 95 10:06:27 PDT From: Haible_Juergen#Tel2743 To: DIY , till Subject: Re: AW: VC pots Date: Thu, 26 Oct 95 10:05:00 PDT Message-Id: <308FC013@MSMGATE.M30X.NBG.SCN.DE> Encoding: 40 TEXT X-Mailer: Microsoft Mail V3.0 Sender: owner-synth-diy@horus.sara.nl Precedence: bulk > pro's: nonlinear (quadratic?) CV response is often desirable > (in compressors and in phasers) > small component, easy to layout the pcb > >The response isn't a quadratic curve, but I don't know that it's >anything especially useful. This is just from trial and error (I have to look into those books again for FET theory): Building a Phaser with linear gain cells and sweeping it with a triangle generator reqires an exponential function to achieve a smooth sweeping sound. Phasers with FETs sound nice with the triangle directly contolling the gates. > I'm pretty sure all special VCA chips are in fact OTAs. I don't know the exact definition for "OTA", but I think some VCA circuits use a modified 4-quadrant-multiplier structure and have the audio signal modulating the *current sources* of the two long tailed pairs, routing the *control voltage* to the bases of the pairs. There are many VCA's which have a "normal" OTA as a core and lots of linearisation circuits, of course. I'd like to know more about the pro's and con's of these two concepts. The first one is tempting, 'cause the current sources can be modulated very linear with quite high voltages. But there must be some drawbacks, too ... I am not sure about that, but maybe those VCA's that have a large input voltage range (and not a current input or millivolt input) *might* have this structure. I have seen this on some old DBX IC. Maybe the old SSM2020, too? (I am just guessing, but I doubt they have integrated the divide-down resistors You need for +/- 10V inputs on an OTA) Just some thoughts - I'd be pleased with any further information or correction. JH. From owner-synth-diy Thu Oct 26 09:19:30 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA20896; Thu, 26 Oct 1995 09:19:30 GMT Received: from zaphod.axion.bt.co.uk by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA112278; Thu, 26 Oct 1995 10:19:23 +0100 Received: from roundabout.bt-sys.bt.co.uk by zaphod.axion.bt.co.uk with SMTP (PP); Thu, 26 Oct 1995 09:18:35 +0000 Received: from argon.bt-sys.bt.co.uk by roundabout.bt-sys.bt.co.uk (8.6.9/BT-SYS-8.6.9) id KAA00136; Thu, 26 Oct 1995 10:16:47 +0100 Received: from silver.bt-sys.bt.co.uk by argon.bt-sys.bt.co.uk (4.1/SMI-4.1) id AA01010; Thu, 26 Oct 95 10:20:01 BST Received: by silver.bt-sys.bt.co.uk (5.x/SMI-SVR4) id AA16694; Thu, 26 Oct 1995 10:19:58 +0100 Date: Thu, 26 Oct 1995 10:19:58 +0100 From: jupiter4@bt-sys.bt.co.uk (Dave's Synth account) Message-Id: <9510260919.AA16694@silver.bt-sys.bt.co.uk> To: synth-diy@horus.sara.nl, ms20@wolfenet.com Subject: Re: (fwd) Moog Music Announces 1996 Product Line (fwd) X-Sun-Charset: US-ASCII Sender: owner-synth-diy@horus.sara.nl Precedence: bulk Hi Gang, Is this for real, Moog back in the thick of it with modulars and all....???? Cheers, Dave .......... From owner-synth-diy Thu Oct 26 11:57:22 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA111712; Thu, 26 Oct 1995 11:57:22 GMT Received: from ns.scn.de by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA42578; Thu, 26 Oct 1995 12:57:17 +0100 Received: (from uucp@localhost) by proxy.scn.de (8.6.11/8.6.11) id MAA13775; Thu, 26 Oct 1995 12:53:45 +0100 Received: from marina.scn.de(192.129.41.2) by proxy.scn.de via smap (V1.3) id sma013670; Thu Oct 26 12:53:08 1995 Received: (from uucp@localhost) by marina.scn.de (8.6.11/8.6.11) id MAA15514; Thu, 26 Oct 1995 12:56:24 +0100 Received: from r316.m30x.nbg.scn.de(142.120.5.16) by marina.scn.de via smap (V1.3) id sma015461; Thu Oct 26 12:56:17 1995 Received: from msmgate.m30x.nbg.scn.de by r316.m30x.nbg.scn.de id aa24275; 26 Oct 95 12:55 MEZ Received: by MSMGATE.M30X.NBG.SCN.DE with Microsoft Mail id <308FE7F6@MSMGATE.M30X.NBG.SCN.DE>; Thu, 26 Oct 95 12:56:38 PDT From: Haible_Juergen#Tel2743 To: analogue , DIY Subject: ASR module is running! Date: Thu, 26 Oct 95 12:55:00 PDT Message-Id: <308FE7F6@MSMGATE.M30X.NBG.SCN.DE> Encoding: 42 TEXT X-Mailer: Microsoft Mail V3.0 Sender: owner-synth-diy@horus.sara.nl Precedence: bulk Hi! After some minor difficulties, I got my Analogue Shift Register Module running this morning! I *love* playing with the second VCO following the first one with a delay of two keystrokes - independent of the time between the strokes! (I found a delay of 2 clock pulses musically more interesting than just a delay of one pulse, 'cause when I am playing melodies, two adjacent notes often form dissonant intervalls.) Problems during construction: (1) The pulses for the different sample&Hold stages may not overlapp by any means! I got this warning from the list before I started building; thanks again, You helped me save much time. I did a redesign with another monoflop between each stage to provide a secure and well defined gap between the sample pulses. (2) I made a great mistake with my S&H design. I wanted to use a S&H with overall feedback to gain maximum accuracy, but I didn't prevent the input opamp from saturating. The effect was this: Everything worked fine for increasing input voltages. But as soon as a decreasing voltage should have been held by closing that n-channel JFET switch, the input opamp's output went to the negative rail and made the FET conduct again. I looked in Tietze/Schenk and found the cure: Two diodes and a resistor clamping the first opamp within +/-.7V of the sampled output voltage. It's still only the naked pcb, no complete module. So wait a few weeks before You ask for schematics (;->). Just had to share this moment of first success with You all (after a rather frustrating loooong night yesterday)! JH. PS.: As I have borrowed the idea (not the circuit!) from the wonderful Serge catalogue, I can only recommend this Serge Modular to all non-builders who want to have a powerful Patchable. These guys have nice ideas! From owner-synth-diy Thu Oct 26 12:18:11 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA117449; Thu, 26 Oct 1995 12:18:11 GMT Received: from ns.scn.de by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA15791; Thu, 26 Oct 1995 13:18:06 +0100 Received: (from uucp@localhost) by proxy.scn.de (8.6.11/8.6.11) id NAA16140 for ; Thu, 26 Oct 1995 13:14:40 +0100 Received: from marina.scn.de(192.129.41.2) by proxy.scn.de via smap (V1.3) id sma016101; Thu Oct 26 13:14:26 1995 Received: (from uucp@localhost) by marina.scn.de (8.6.11/8.6.11) id NAA19553 for ; Thu, 26 Oct 1995 13:17:41 +0100 Received: from r316.m30x.nbg.scn.de(142.120.5.16) by marina.scn.de via smap (V1.3) id sma019531; Thu Oct 26 13:17:36 1995 Received: by r316.m30x.nbg.scn.de id ab24411; 26 Oct 95 13:16 MEZ Received: from msmgate.m30x.nbg.scn.de by r316.m30x.nbg.scn.de id aa24335; 26 Oct 95 13:10 MEZ Received: by MSMGATE.M30X.NBG.SCN.DE with Microsoft Mail id <308FEB7E@MSMGATE.M30X.NBG.SCN.DE>; Thu, 26 Oct 95 13:11:42 PDT From: Haible_Juergen#Tel2743 To: DIY Subject: RE: CV Crossfader? Date: Thu, 26 Oct 95 13:10:00 PDT Message-Id: <308FEB7E@MSMGATE.M30X.NBG.SCN.DE> Encoding: 12 TEXT X-Mailer: Microsoft Mail V3.0 Sender: owner-synth-diy@horus.sara.nl Precedence: bulk > Does anyone have a good schematic for a CV crossfader? Seems like it > would be similar to a CV'd mixer, but wouldn't you need non-linear control? Both lnear and expo crossfade are useful. The LFO/noise section of the Prophet 5 rev. 3 service manual shows a nice linear crossfade circuit. For expo crossfade, use a PNP long tailed pair to control the balance of the control currents of two OTA's. JH. From owner-synth-diy Thu Oct 26 12:41:57 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA120989; Thu, 26 Oct 1995 12:41:57 GMT Received: from xgw1.pal.xgw.fi by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA83859; Thu, 26 Oct 1995 13:41:53 +0100 Received: from netcontrol.netcontrol.fi (netcontrol.netcontrol.fi [193.210.7.1]) by mail.xgw.fi (8.6.11/8.6.4) with ESMTP id OAA29413 for ; Thu, 26 Oct 1995 14:45:18 +0200 Received: (from jocke@localhost) by netcontrol.netcontrol.fi (8.6.11/8.6.9) id OAA20134; Thu, 26 Oct 1995 14:41:58 +0200 Date: Thu, 26 Oct 1995 14:41:57 +0200 (EET) From: Joachim Verghese To: Synth DIY Subject: RE: CV Crossfader? In-Reply-To: <308FEB7E@MSMGATE.M30X.NBG.SCN.DE> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-synth-diy@horus.sara.nl Precedence: bulk > > Does anyone have a good schematic for a CV crossfader? Seems like it > > would be similar to a CV'd mixer, but wouldn't you need non-linear > control? > > Both lnear and expo crossfade are useful. > The LFO/noise section of the Prophet 5 rev. 3 service manual shows > a nice linear crossfade circuit. For expo crossfade, use a PNP > long tailed pair to control the balance of the control currents of > two OTA's. The SSM-2024 data sheet shows how to build an exponential crossfader. -joachim From owner-synth-diy Fri Oct 27 07:13:28 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA20364; Fri, 27 Oct 1995 07:13:28 GMT Received: from netcom2.netcom.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA81539; Fri, 27 Oct 1995 08:13:25 +0100 Received: by netcom2.netcom.com (8.6.12/Netcom) id AAA12062; Fri, 27 Oct 1995 00:11:57 -0700 Date: Fri, 27 Oct 1995 00:11:57 -0700 Message-Id: <199510270711.AAA12062@netcom2.netcom.com> To: synth-diy@horus.sara.nl In-Reply-To: <308FC013@MSMGATE.M30X.NBG.SCN.DE> (message from Haible_Juergen#Tel2743 on Thu, 26 Oct 95 10:05:00 PDT) Subject: Re: AW: VC pots Reply-To: don@till.com From: Don Tillman Organization: Don's house, Palo Alto, California Sender: owner-synth-diy@horus.sara.nl Precedence: bulk From: Haible_Juergen Date: Thu, 26 Oct 95 10:05:00 PDT FETs: Also note that there is this linearizing hack: you can mix 1/2 the audio signal into the control signal at the gate to eliminate the most pronounced distortion component. Fans of symmetry will equate this with setting the ac voltage at the gate to midway between the ac voltage at the source and drain. > I'm pretty sure all special VCA chips are in fact OTAs. I don't know the exact definition for "OTA", but I think some VCA circuits use a modified 4-quadrant-multiplier structure and have the audio signal modulating the *current sources* of the two long tailed pairs, routing the *control voltage* to the bases of the pairs. Ah yes, of course! This arrangement does deserve a seperate catagory because the circuit configuaration has sufficiently different characteristics. -- Don From owner-synth-diy Fri Oct 27 09:14:38 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA87827; Fri, 27 Oct 1995 09:14:38 GMT Received: from ns.scn.de by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA100613; Fri, 27 Oct 1995 10:14:30 +0100 Received: (from uucp@localhost) by proxy.scn.de (8.6.11/8.6.11) id KAA25818 for ; Fri, 27 Oct 1995 10:11:03 +0100 Received: from marina.scn.de(192.129.41.2) by proxy.scn.de via smap (V1.3) id sma025764; Fri Oct 27 10:10:34 1995 Received: (from uucp@localhost) by marina.scn.de (8.6.11/8.6.11) id KAA16209 for ; Fri, 27 Oct 1995 10:13:51 +0100 Received: from r316.m30x.nbg.scn.de(142.120.5.16) by marina.scn.de via smap (V1.3) id sma016107; Fri Oct 27 10:13:23 1995 Received: from msmgate.m30x.nbg.scn.de by r316.m30x.nbg.scn.de id aa27938; 27 Oct 95 10:12 MEZ Received: by MSMGATE.M30X.NBG.SCN.DE with Microsoft Mail id <3091134A@MSMGATE.M30X.NBG.SCN.DE>; Fri, 27 Oct 95 10:13:46 PDT From: Haible_Juergen#Tel2743 To: DIY Subject: Re: AW: VC pots Date: Fri, 27 Oct 95 10:12:00 PDT Message-Id: <3091134A@MSMGATE.M30X.NBG.SCN.DE> Encoding: 16 TEXT X-Mailer: Microsoft Mail V3.0 Sender: owner-synth-diy@horus.sara.nl Precedence: bulk > I don't know the exact definition for "OTA", but I think some > VCA circuits use a modified 4-quadrant-multiplier structure and > have the audio signal modulating the *current sources* of > the two long tailed pairs, routing the *control voltage* > to the bases of the pairs. > >Ah yes, of course! This arrangement does deserve a seperate catagory >because the circuit configuaration has sufficiently different >characteristics. Do You know something about the drawbacks of this architecture? I heard that with these VCAs distortion would increase with decreasing control voltage, but I haven't dug deeper into that. Any ideas? JH. From owner-synth-diy Sat Oct 28 05:06:51 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA61692; Sat, 28 Oct 1995 05:06:51 GMT Received: from atl1.america.net by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA63988; Sat, 28 Oct 1995 06:06:49 +0100 Received: (from edison@localhost) by america.net (8.6.10/8.6.9) id FAA27562; Sat, 28 Oct 1995 05:03:30 GMT Date: Sat, 28 Oct 1995 01:03:30 -0400 (EDT) From: EDISON X-Sender: edison@atl1 To: synth-diy@horus.sara.nl Subject: ?1/volt oct to linear? Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-synth-diy@horus.sara.nl Precedence: bulk I would like to be able to use a Yamaha CS-15 with a mpu-101 midi to c.v converter, I built a trigger converter using a relay(Is their a less barbaric way) but need to convert 1/volt octave to linear response. Can this be done? I can't find any info on it. Thanks From owner-synth-diy Sat Oct 28 07:52:21 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA105441; Sat, 28 Oct 1995 07:52:21 GMT Received: from aahz.magic.mb.ca by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA79580; Sat, 28 Oct 1995 08:52:19 +0100 Received: from merlin.magic.mb.ca by aahz with smtp (Smail3.1.29.1 #4) id m0t963o-000SWXC; Sat, 28 Oct 95 02:52 CDT Received: from dialb11.magic.mb.ca by merlin.magic.mb.ca with smtp (Smail3.1.29.1 #2) id m0t963n-000KbeC; Sat, 28 Oct 95 02:52 CDT Message-Id: Date: Sat, 28 Oct 95 02:52 CDT X-Sender: rmiller@merlin.magic.mb.ca Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: synth-diy@horus.sara.nl From: rmiller@magic.mb.ca (Ric) Subject: ?1/volt oct to linear? X-Mailer: Sender: owner-synth-diy@horus.sara.nl Precedence: bulk >From: EDISON >I would like to be able to use a Yamaha CS-15 with a mpu-101 midi to c.v >converter, I built a trigger converter using a relay(Is their a less >barbaric way) but need to convert 1/volt octave to linear response. >Can this be done? I can't find any info on it. >Thanks With a relay??? WOW! Great innovation! I haven't heard of anything like that since setting up a 'memory bank' for a modular synth, using relays, in a 197?'s edition of Electronotes! Otherwise, for your other intended conversion .... nothing easy. You'll have to build a converter for that, and not knowing for sure how, I know you'll need a tempco resistor and matched transistor pair, for sure. :/ The former is the more difficult to get. Not impossible, just difficult. Ric From owner-synth-diy Mon Oct 30 09:02:31 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA28194; Mon, 30 Oct 1995 09:02:31 GMT Received: from ns.scn.de by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA99021; Mon, 30 Oct 1995 10:02:23 +0100 Received: (from uucp@localhost) by proxy.scn.de (8.6.11/8.6.11) id JAA10207; Mon, 30 Oct 1995 09:58:53 +0100 Received: from marina.scn.de(192.129.41.2) by proxy.scn.de via smap (V1.3) id sma010170; Mon Oct 30 09:58:43 1995 Received: (from uucp@localhost) by marina.scn.de (8.6.11/8.6.11) id KAA11888; Mon, 30 Oct 1995 10:02:02 +0100 Received: from r316.m30x.nbg.scn.de(142.120.5.16) by marina.scn.de via smap (V1.3) id sma011726; Mon Oct 30 10:01:14 1995 Received: from msmgate.m30x.nbg.scn.de by r316.m30x.nbg.scn.de id aa09428; 30 Oct 95 9:59 MEZ Received: by MSMGATE.M30X.NBG.SCN.DE with Microsoft Mail id <309512FF@MSMGATE.M30X.NBG.SCN.DE>; Mon, 30 Oct 95 10:01:35 PST From: Haible_Juergen#Tel2743 To: analogue , DIY Subject: discoveries of the weekend Date: Mon, 30 Oct 95 10:01:00 PST Message-Id: <309512FF@MSMGATE.M30X.NBG.SCN.DE> Encoding: 34 TEXT X-Mailer: Microsoft Mail V3.0 Sender: owner-synth-diy@horus.sara.nl Precedence: bulk Hi! I spent some hours to take a close look at a friend's enormous service docs' collection, and here are some things I have found: Korg MS-50: This ultra-rare beast's Lowpass Filter is based on an integrated diode ring (CA3019)! It is just the common (Sallen&Key?) LP filter, with the resistors replaced by diodes. An extra feedback path is added for variable resonance. The MS-50's VCA is also built with a CA3019 diode ring. Korg PS-3100: Now I have seen how those famous Resonators are built! Speaking of active components: dead cheap. Again a simple one-opamp BP filter for each resonant peak. But the resistors are replaced by photocouplers - a quite common technique in Korg synths of that area. I haven't seen an extra resonance control part - but they might individually control the two resistors to get differt Q's - have to look again at home. Roland SH-5: Now this was the great surprise! While the later SH-7 has 4-pole ota-filters, now guess what's inside the earlier SH-5: It's a *diode ladder*, very similar to the TB-303 and the EMS Synthi A. (There are additional BP and HP filters - it's the LP filter I was talking about.) JH. From owner-synth-diy Mon Oct 30 10:11:08 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA90623; Mon, 30 Oct 1995 10:11:08 GMT Received: from bacher.co.at by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA119531; Mon, 30 Oct 1995 11:11:05 +0100 Received: from dell_pc15.co.at by bacher.co.at (SMI-8.6/SMI-SVR4) id LAA15343; Mon, 30 Oct 1995 11:09:47 +0100 From: mz@bacher.co.at (Michael Zacherl - Bacher Systems EDV GmbH) To: synth-diy@horus.sara.nl Subject: TB-303 Replica Reply-To: mz@bacher.co.at Date: Mon, 30 Oct 95 10:09:37 GMT Message-Id: <9510301009.25435C@dell_pc15.co.at> X-Mailer: E-Mail 1.6 Sender: owner-synth-diy@horus.sara.nl Precedence: bulk >Now this was the great surprise! While the later SH-7 has 4-pole >ota-filters, now guess what's inside the earlier SH-5: >It's a *diode ladder*, very similar to the TB-303 and the EMS >Synthi A. >(There are additional BP and HP filters - it's the LP filter I was >talking about.) Speaking of the TB-303: would it be possible (in terms of availability of components) and worthwhile to build a replica of this thing? It looks rather simple in design. What problems would one have to expect to encouter? Has anyone the schematics at hands? /mz ---------------- Sun - Power that SPARCles. --------------- Michael Zacherl phone : +43 (1) 60 126-253 Bacher Systems EDV GmbH fax : +43 (1) 60 126-4 Wienerbergstr. 11B e-mail: mz@bacher.co.at A-1101 Wien www : http://www.bacher.co.at/sun/ *updated* Austria From owner-synth-diy Mon Oct 30 11:03:31 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA23922; Mon, 30 Oct 1995 11:03:31 GMT Received: from ns.scn.de by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA54619; Mon, 30 Oct 1995 12:03:27 +0100 Received: (from uucp@localhost) by proxy.scn.de (8.6.11/8.6.11) id LAA22483 for ; Mon, 30 Oct 1995 11:59:56 +0100 Received: from marina.scn.de(192.129.41.2) by proxy.scn.de via smap (V1.3) id sma022404; Mon Oct 30 11:59:06 1995 Received: (from uucp@localhost) by marina.scn.de (8.6.11/8.6.11) id MAA04874 for ; Mon, 30 Oct 1995 12:02:24 +0100 Received: from r316.m30x.nbg.scn.de(142.120.5.16) by marina.scn.de via smap (V1.3) id sma004541; Mon Oct 30 12:01:46 1995 Received: from msmgate.m30x.nbg.scn.de by r316.m30x.nbg.scn.de id aa10009; 30 Oct 95 12:00 MEZ Received: by MSMGATE.M30X.NBG.SCN.DE with Microsoft Mail id <30952F3C@MSMGATE.M30X.NBG.SCN.DE>; Mon, 30 Oct 95 12:02:04 PST From: Haible_Juergen#Tel2743 To: DIY Subject: RE: TB-303 Replica Date: Mon, 30 Oct 95 12:01:00 PST Message-Id: <30952F3C@MSMGATE.M30X.NBG.SCN.DE> Encoding: 13 TEXT X-Mailer: Microsoft Mail V3.0 Sender: owner-synth-diy@horus.sara.nl Precedence: bulk > >Speaking of the TB-303: would it be possible (in terms of >availability of components) and worthwhile to build a replica >of this thing? It looks rather simple in design. > >What problems would one have to expect to encouter? >Has anyone the schematics at hands? A friend of mine has done this. It's called the Transistorbass-3 and is available from TBS, Fuerth, Germany. JH. From owner-synth-diy Mon Oct 30 11:19:06 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA19907; Mon, 30 Oct 1995 11:19:06 GMT Received: from bacher.co.at by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA21431; Mon, 30 Oct 1995 12:19:03 +0100 Received: from dell_pc15.co.at by bacher.co.at (SMI-8.6/SMI-SVR4) id MAA16021; Mon, 30 Oct 1995 12:18:49 +0100 From: mz@bacher.co.at (Michael Zacherl - Bacher Systems EDV GmbH) To: synth-diy@horus.sara.nl Subject: RE: TB-303 Replica Reply-To: mz@bacher.co.at Date: Mon, 30 Oct 95 11:18:38 GMT Message-Id: <9510301118.262038@dell_pc15.co.at> X-Mailer: E-Mail 1.6 Sender: owner-synth-diy@horus.sara.nl Precedence: bulk >>Speaking of the TB-303: would it be possible (in terms of >>availability of components) and worthwhile to build a replica >>of this thing? It looks rather simple in design. >> >>What problems would one have to expect to encouter? >>Has anyone the schematics at hands? >A friend of mine has done this. It's called the Transistorbass-3 >and is available from TBS, Fuerth, Germany. >JH. well ... I read some critics about the Transistorbass-3 and other products which try to pretend beeing a TB303. Most comments are like "Pretty good, but certainly not the same". So is it a true replica or not? If yes, why is it stated as sounding different? /Michael From owner-synth-diy Mon Oct 30 12:04:13 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA59691; Mon, 30 Oct 1995 12:04:13 GMT Received: from ns.scn.de by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA53786; Mon, 30 Oct 1995 13:04:10 +0100 Received: (from uucp@localhost) by proxy.scn.de (8.6.11/8.6.11) id NAA29243 for ; Mon, 30 Oct 1995 13:00:41 +0100 Received: from marina.scn.de(192.129.41.2) by proxy.scn.de via smap (V1.3) id sma029129; Mon Oct 30 12:59:50 1995 Received: (from uucp@localhost) by marina.scn.de (8.6.11/8.6.11) id NAA18505 for ; Mon, 30 Oct 1995 13:03:09 +0100 Received: from r316.m30x.nbg.scn.de(142.120.5.16) by marina.scn.de via smap (V1.3) id sma018393; Mon Oct 30 13:02:33 1995 Received: from msmgate.m30x.nbg.scn.de by r316.m30x.nbg.scn.de id aa10285; 30 Oct 95 13:01 MEZ Received: by MSMGATE.M30X.NBG.SCN.DE with Microsoft Mail id <30953D7F@MSMGATE.M30X.NBG.SCN.DE>; Mon, 30 Oct 95 13:02:55 PST From: Haible_Juergen#Tel2743 To: DIY Subject: RE: TB-303 Replica Date: Mon, 30 Oct 95 13:01:00 PST Message-Id: <30953D7F@MSMGATE.M30X.NBG.SCN.DE> Encoding: 35 TEXT X-Mailer: Microsoft Mail V3.0 Sender: owner-synth-diy@horus.sara.nl Precedence: bulk >well ... I read some critics about the Transistorbass-3 and >other products which try to pretend beeing a TB303. Most >comments are like "Pretty good, but certainly not the same". > >So is it a true replica or not? If yes, why is it stated as >sounding different? Well, what is a true replica? If You'd take an original Roland 303 and put it into a green box, some people would swear they heard "differences" in in the sound. OTAH, there's this load of crap in the press where people claim You can emulate a 303 with a CEM filter. I must admit I am *very* bored by the whole topic. Well, to keep it short, the Transistorbass-3 is not a replica in the sense that they have an "xyz" transistor soldered out of an actual Roland 303, and planted it into the Braintec one. But I *hope* buying the same xyz transistor from Japan should be close enough (;->). Just an example. You get the clue. Of course, the 303's sequencer is replaced by a Midi Interface. And also well known, the "303"-type sonic capabillites are just a small "subset" of the Transistorbass' features. The owner's manual (which is one of the most comprehensible ones I have ever seen, btw.) tells You exactly which knobs You have to put on the left position to get a "true" 303 emulation. Hope this helps. And again (how often did I say this before?): Personally I cannot understand why anybody would like to use any synth just to emulate a 303. I never liked the 303, nor do I like the music that usually is created with it. But if You want exactly this sound (plus many things more), and You want to go Midi, and can't afford a real 303, the Transistorbass is definetly the way to go. You can't get closer. JH. From owner-synth-diy Mon Oct 30 20:29:46 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA32312; Mon, 30 Oct 1995 20:29:46 GMT Received: from qed.cloverleaf.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA17458; Mon, 30 Oct 1995 21:29:42 +0100 Received: from [205.153.188.103] (stanton-1-3.cloverleaf.com [205.153.188.103]) by qed.cloverleaf.com (8.6.5/8.6.5) with SMTP id MAA03702 for ; Mon, 30 Oct 1995 12:27:36 -0800 X-Sender: haines@mail.quick.net Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Mon, 30 Oct 1995 12:36:37 -0800 To: synth-diy@horus.sara.nl From: haines@quick.net (Matt Haines) Subject: RE: TB-303 Replica Sender: owner-synth-diy@horus.sara.nl Precedence: bulk Bzzzzzzzzzzt!! Ting! Kerplong!!!!!...Haible_Juergen#Tel2743 froodle!!! : >A friend of mine has done this. It's called the Transistorbass-3 >and is available from TBS, Fuerth, Germany. > But no sequencer, right? That's really the key to the sound. Matt Haines haines@quick.net \co/ntrol-X \to /\abort / \transmission. "As 'something' inside was dieing, I noticed the display was freaking out, displaying dark bars that would start on one end and grow until they reached across the entire display, and other things too."...R. Marshall From owner-synth-diy Mon Oct 30 23:45:55 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA78553; Mon, 30 Oct 1995 23:45:55 GMT Received: from fibermux.fibermux.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA103636; Tue, 31 Oct 1995 00:45:52 +0100 Received: from ccrelay.fibermux.com by fibermux.fibermux.com (4.1/SMI-4.1) id AA23786; Mon, 30 Oct 95 15:48:41 PST Received: from cc:Mail by ccrelay.fibermux.com id AA815096762; Mon, 30 Oct 95 15:45:31 PDT Date: Mon, 30 Oct 95 15:45:31 PDT From: gstopp@fibermux.com Encoding: 60 Text Message-Id: <9509308150.AA815096762@ccrelay.fibermux.com> To: synth-diy@horus.sara.nl Subject: Another module experiment Sender: owner-synth-diy@horus.sara.nl Precedence: bulk Hi List, I've managed to throw together another module. This one falls into the "I've wanted to build one for twenty years" category - it's the "Quasi-Digital Bi-N-Tic Filter" as shown in Electronotes issue #92, page 15. This filter is a 2-stage 8-tap commutating (multiplexed capacitor) filter in a state-variable configuration. The input signal is summed with the output plus the Q pot wiper, and is fed into 2 stages of 8-tap capacitor analog muxes made from 4051's. The Q pot is tapped from the output of the first stage. The module's output is the output of the second stage. The analog muxes are clocked by a counter that is driven by a high-speed VCO. There is also a pot called "Bandwidth" which is a dual unit, with one half at the input of the first stage and the other half at the input of the second stage. For my circuit I used a 4046 as a VCO, driving a 74HCT163 synchronous 4-bit counter, whose A,B,C outputs drive the A,B,C inputs of the muxes. For the muxes I used 74HCT4051's. These chips run off of plus and minus 5 volts since they have an 18 volt max terminal-to-terminal rating. For the integrators of each pole I used CA3140's, and the audio input summer and output buffer are an LM358 dual. I also used an LM358 for the CV input summers for the VCO (two inverters in a row). Power was provided by a small linear suppy at +12v, +5v, -5v, and -12v. Assembly was un-eventful, aside from the usual "duh" mistakes. Didn't blow anything up this time. For the audio input I used a single op-amp LFO producing a square wave at about 80 hertz, amplitude about 3 volts peak-to-peak. For monitoring I drove a pair of headphones directly from the output op-amp (which actually works rather well, in case you don't know that trick). The sound? Weird. I came to the conclusion that the "Bandwidth" pot and the VCO frequency pot have useful ranges that are a small percentage of their full rotation. I suspect that they are inter-related in these ranges so I don't want to jump to conclusions yet. The VCO is set up to run from zero hertz to 2 Mhz in one sweep from zero to +12 volts on the CV input, so I expected that for that particular control. Also the dual "Bandwidth" pot is 250K instead of 100K so I'm not surprised there either. The Q pot can cause oscillation if turned up all the way, if you can call it oscillation (let's just say the output gets into this "high-amplitude craziness" mode). It has the same "max feedback is minimum Q" characteristics as the Q pot on a state-variable design. Anyway at the least weird setting the filter sounded somewhat like a flanger with high resonance when the clock frequency is swept. You can also tell by listening that there are several notches (or peaks?) in the swept spectrum. Overall the effect is very clangey and bell-like. Many inharmonicities and alias-like noises, quite grungey. More experimentation is needed with a wider range of input types (like noise, etc.)..... - Gene gstopp@fibermux.com From owner-synth-diy Tue Oct 31 08:14:06 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA38852; Tue, 31 Oct 1995 08:14:06 GMT Received: from ns.scn.de by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA101815; Tue, 31 Oct 1995 09:13:57 +0100 Received: (from uucp@localhost) by proxy.scn.de (8.6.11/8.6.11) id JAA04727 for ; Tue, 31 Oct 1995 09:10:29 +0100 Received: from marina.scn.de(192.129.41.2) by proxy.scn.de via smap (V1.3) id sma004634; Tue Oct 31 09:09:27 1995 Received: (from uucp@localhost) by marina.scn.de (8.6.11/8.6.11) id JAA00366 for ; Tue, 31 Oct 1995 09:12:46 +0100 Received: from r316.m30x.nbg.scn.de(142.120.5.16) by marina.scn.de via smap (V1.3) id sma000247; Tue Oct 31 09:12:04 1995 Received: from msmgate.m30x.nbg.scn.de by r316.m30x.nbg.scn.de id aa14450; 31 Oct 95 9:10 MEZ Received: by MSMGATE.M30X.NBG.SCN.DE with Microsoft Mail id <309658F9@MSMGATE.M30X.NBG.SCN.DE>; Tue, 31 Oct 95 09:12:25 PST From: Haible_Juergen#Tel2743 To: DIY Subject: RE: TB-303 Replica Date: Tue, 31 Oct 95 09:11:00 PST Message-Id: <309658F9@MSMGATE.M30X.NBG.SCN.DE> Encoding: 6 TEXT X-Mailer: Microsoft Mail V3.0 Sender: owner-synth-diy@horus.sara.nl Precedence: bulk >But no sequencer, right? Right. JH. From owner-synth-diy Tue Oct 31 13:19:27 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA54622; Tue, 31 Oct 1995 13:19:27 GMT Received: from vulcan.le.ac.uk by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA43352; Tue, 31 Oct 1995 14:19:25 +0100 Received: from hawk.le.ac.uk by vulcan with SMTP (PP); Tue, 31 Oct 1995 13:14:42 +0000 From: "D.V. Mitchell" Message-Id: <13779.199510311314@hawk.le.ac.uk> Subject: Frequency changing stuff... To: synth-diy@horus.sara.nl Date: Tue, 31 Oct 1995 13:14:34 +0000 (GMT) X-Mailer: ELM [version 2.4 PL22] Content-Type: text Content-Length: 1476 Sender: owner-synth-diy@horus.sara.nl Precedence: bulk Hi... I've been reading this page for about six months, under various addresses... It's really good, and helped me e.t.c.... I've got a question, I've thought up two projects, one of which will be too complicated for analogue, so I'll probably use DSP's... But the other can be done in either analogue or digital (I hope)... I'ts not really a synth circuit, (well for the application I'm going to use it for, but the end circuit could be modified to give some effects... Basically I need to get a full range audio signal, and increase it's frequency by two or three hz... err... My first thoughts, were get a computer to do it, but thats not what I want... It would be really cool, if it could be analogue, e.g. small, less complicated that building a single board computer, cheaper to build, better quality (maybe)... I need it to be of extremely good quality, as if it wasn't it would be no good for the application I've got in mind for it, and the system would be better off without it... Does anyone have any ideas, of how such a feat, could be achieved with analogue electronics... Also I built one of them 'State Variable Filters' In the TI OpAmp data book... As my maths isn't all that hot, I used the rules of thumb (given below it), and built the filter... But now, it sort of works, (sometimes), but then other times all the signal paths seem to 'clog up' with the supply, and inbetween D.C. voltages... Very confusing... Thanks... Damian Mitchell dvm1@le.ac.uk From owner-synth-diy Tue Oct 31 14:10:18 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA120696; Tue, 31 Oct 1995 14:10:18 GMT Received: from ns.scn.de by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA87614; Tue, 31 Oct 1995 15:09:53 +0100 Received: (from uucp@localhost) by proxy.scn.de (8.6.11/8.6.11) id PAA12114; Tue, 31 Oct 1995 15:06:18 +0100 Received: from marina.scn.de(192.129.41.2) by proxy.scn.de via smap (V1.3) id sma012001; Tue Oct 31 15:05:26 1995 Received: (from uucp@localhost) by marina.scn.de (8.6.11/8.6.11) id PAA03948; Tue, 31 Oct 1995 15:08:45 +0100 Received: from r316.m30x.nbg.scn.de(142.120.5.16) by marina.scn.de via smap (V1.3) id sma003899; Tue Oct 31 15:08:36 1995 Received: from msmgate.m30x.nbg.scn.de by r316.m30x.nbg.scn.de id aa16319; 31 Oct 95 15:07 MEZ Received: by MSMGATE.M30X.NBG.SCN.DE with Microsoft Mail id <3096AC86@MSMGATE.M30X.NBG.SCN.DE>; Tue, 31 Oct 95 15:08:54 PST From: Haible_Juergen#Tel2743 To: analogue , DIY Subject: crazy modular drummers Date: Tue, 31 Oct 95 15:07:00 PST Message-Id: <3096AC86@MSMGATE.M30X.NBG.SCN.DE> Encoding: 27 TEXT X-Mailer: Microsoft Mail V3.0 Sender: owner-synth-diy@horus.sara.nl Precedence: bulk Hi! This might not be new to You, but I had a lot of fun with it. The idea is controlling a nearly self-oscillating filter by both a sequencer and a sample&hold, clocked from the same LFO. In details: I used my SSM2040 filter module to produce percussion sounds, like it was described many times before: The gate output of the sequencer is fed into the filter's signal input to make the filter ring and exponentially decay. At the same time the sequencer's CV out controls the filter cutoff frequency. All in all You get the impression of tuned percussion, like a band of african drummers who use tuned/tunable drums (is that "talking drum" or something similar?). Now I am adding the S&H voltage, giving the whole thing a slightly random structure: no stroke is exactly the same as in the previous bar. Increasing the S&H amount drives Your "virtual negroes" crazy - it's like they are falling in trance and create unpredictable pitches - You can blend this up to full "classic" S&H effects, but IMO it's the slow transition from the tribal drums to the insane s&h effect that makes the whole thing interesting. JH. From owner-synth-diy Tue Oct 31 18:44:03 1995 Received: by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA68133; Tue, 31 Oct 1995 18:44:03 GMT Received: from netcom21.netcom.com by horus.sara.nl (AIX 3.2/UCB 5.64/4.03) id AA20510; Tue, 31 Oct 1995 19:44:00 +0100 Received: by netcom21.netcom.com (8.6.12/Netcom) id KAA08442; Tue, 31 Oct 1995 10:33:40 -0800 Date: Tue, 31 Oct 1995 10:33:40 -0800 Message-Id: <199510311833.KAA08442@netcom21.netcom.com> To: dvm1@leicester.ac.uk Cc: synth-diy@horus.sara.nl In-Reply-To: <13779.199510311314@hawk.le.ac.uk> (dvm1@leicester.ac.uk) Subject: Re: Frequency changing stuff... Reply-To: don@till.com From: Don Tillman Organization: Don's house, Palo Alto, California Sender: owner-synth-diy@horus.sara.nl Precedence: bulk Date: Tue, 31 Oct 1995 13:14:34 +0000 (GMT) From: "D.V. Mitchell" I've got a question, I've thought up two projects, one of which will be too complicated for analogue, so I'll probably use DSP's... And you're not going to tell us what it is? But the other can be done in either analogue or digital (I hope)... I'ts not really a synth circuit, (well for the application I'm going to use it for, but the end circuit could be modified to give some effects... Basically I need to get a full range audio signal, and increase it's frequency by two or three hz... Does anyone have any ideas, of how such a feat, could be achieved with analogue electronics... It takes two multipliers (ie., ring modulators), a local sine oscillator with quadrature outputs (0-degrees and 90-degrees) and a pair of phase shift networks for your input signal. It's an electrical implementation of the geometric identity for cosine of the sum of two angles. So it's not a trivial project. Also I built one of them 'State Variable Filters' In the TI OpAmp data book... As my maths isn't all that hot, I used the rules of thumb (given below it), and built the filter... But now, it sort of works, (sometimes), but then other times all the signal paths seem to 'clog up' with the supply, and inbetween D.C. voltages... Very confusing... You understand that the phrase "clog up with the supply" doesn't tell us a heck of a lot. :-) -- Don