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mark_olson
Joined: Oct 26, 2006 Posts: 177 Location: Lawrence, Kansas
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Posted: Sun Jan 10, 2010 12:23 pm Post subject:
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Thanks for the comments.
And thanks too for the schematic for that VCA.
But the most thanks for nudging me toward using the other pair!
Mark |
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stewpye
Joined: Apr 30, 2009 Posts: 49 Location: Brisbane, Australia
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Posted: Fri Jan 29, 2010 2:01 pm Post subject:
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Hi Mark,
You could also use the other pair as a sine wave shaper (diff amp style).
Cheers,
Stew. |
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mark_olson
Joined: Oct 26, 2006 Posts: 177 Location: Lawrence, Kansas
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Posted: Sat Jan 30, 2010 9:08 am Post subject:
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stewpye wrote: | use the other pair as a sine wave shaper |
Thanks for pointing this out.
Sadly, at the rate I'm building even the THAT pair will be obsolete by the time I get to this.
Mark |
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Rykhaard
Joined: Sep 02, 2007 Posts: 1290 Location: Canada
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Posted: Wed Mar 17, 2010 2:23 pm Post subject:
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We only have to match the trannies to within 5mV of each other? (Don Tillman - seems confirmed by one other replier). Back when I were matching them for my KStone VCAs as well as my 2 x Thomas Henry 1V/oct. tranny VCOs, I was matching them to within ONE mV! (Both of those VCOs BTW, track wonderfully with matched 2N3904s; no tempco - over about 5 octaves. They're now my 'standard' LFO choice. )
"Welcome back Rich!"
Thanks! It's been WAY too dang bloody long! |
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24075 Location: The Netherlands, Enschede
Audio files: 277
G2 patch files: 320
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Posted: Wed Mar 17, 2010 2:27 pm Post subject:
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Rykhaard wrote: | "Welcome back Rich!"
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That was my line good to see you round. _________________ Jan
also .. could someone please turn down the thermostat a bit.
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iopop3
Joined: May 28, 2010 Posts: 94 Location: Malmö, Sweden
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Posted: Tue Jun 01, 2010 11:38 am Post subject:
Re: CGS VCO - replacement for the lm394/MAT-02 |
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TonnieWiegman wrote: | Last August I bought 20 pcs of the LM394 for $0.60 each at UTSOURCE: www.utsource.net.
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Was quoted $4 each for 10 lm394 DIP8 this week. Talk about investment, anyone know a stock rasing 666% since august last year? Also got 5 ssm2210z for $5, Just to compare with my local price starting at $11.
Some heads up though, using their site on *nix plus Firefox is quite an experience. Was notified about the quote at work, of course I had to check it out. Tested to place an order and got interrupted in the middle of the processes, had to close that window, some hour later I got an "order confirmation" email.. opps. Luckily it was stuff I really needed. Now its just wait and see if I managed to write down the address correctly. |
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sonicwarrior
Joined: Dec 22, 2005 Posts: 266 Location: Cologne, Germany
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Posted: Wed Oct 20, 2010 3:19 am Post subject:
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andrewF wrote: |
The AD page for it is here. |
Looks like the SSM2210 has been replaced by the SSM2212 which is SOIC-only (SMD). |
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kjackman
Joined: Sep 05, 2010 Posts: 69 Location: Utah, USA
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Posted: Sun Oct 24, 2010 9:28 pm Post subject:
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I can't seem to find SSM2212's in stock anywhere in the U.S. either It really is getting tiresome, looking for these matched transistor ICs.
If I use discrete components instead, hand-matching transistors, would I also need to include the diodes shown between base and emitter on the SSM2210/2212 datasheet? If so, would those diodes need to be "matched" somehow as well, or could I just grab a couple of random 1N4148's from the ol' parts drawer and it'd work just as well? |
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bod
Joined: Apr 28, 2009 Posts: 148 Location: Glasgow
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Posted: Mon Oct 25, 2010 6:55 am Post subject:
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What about the LM/CA3086?
a i seem to remember someone (possibly Yves) saying the connected pair were as good as any hand matched pair, but if you used it with a tempco resistor it would save having to use the heater circuits like the moog rogue. i've seent the 3086 for as little as 1euro if you hunt about a bit.
or am i just talking mince? |
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adambee7
Joined: Apr 04, 2009 Posts: 420 Location: united kingdom
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Posted: Mon Oct 25, 2010 7:25 am Post subject:
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It would be cool if the THAT series of matched pairs were used. i know Oakley have moved over to these for their vcos. brand new and available from mouser. Its getting too hard now to find most npn pairs. i can get ca 3046/86 but its not going to be long until they're scarce. |
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adambee7
Joined: Apr 04, 2009 Posts: 420 Location: united kingdom
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Posted: Mon Oct 25, 2010 7:41 am Post subject:
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oh yeah the japanese 2SC1583 matched pair is another choice. Never tried them but there must be loads of them about. |
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sonicwarrior
Joined: Dec 22, 2005 Posts: 266 Location: Cologne, Germany
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Posted: Mon Oct 25, 2010 10:32 am Post subject:
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bod wrote: | What about the LM/CA3086? |
They are not a direct replacement (DIP 14) and also discontinued.
The SSM2212 is quite new. I guess it takes some time to arrive at the distributors. |
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sonicwarrior
Joined: Dec 22, 2005 Posts: 266 Location: Cologne, Germany
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Posted: Mon Oct 25, 2010 10:35 am Post subject:
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adambee7 wrote: | It would be cool if the THAT series of matched pairs were used. |
Might be a chance to make a dual VCO for not wasting the second matched pair. |
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andrewF
Joined: Dec 29, 2006 Posts: 1176 Location: australia
Audio files: 4
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Posted: Mon Oct 25, 2010 4:28 pm Post subject:
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adambee7 wrote: | oh yeah the japanese 2SC1583 matched pair is another choice. Never tried them but there must be loads of them about. |
they are good but also out of production and have been rare for a while now.
None of the regular suppliers have them anymore. |
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andrewF
Joined: Dec 29, 2006 Posts: 1176 Location: australia
Audio files: 4
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Posted: Mon Oct 25, 2010 8:26 pm Post subject:
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Unless you want to spend lost of $$, may as well learn how to match transistors. There have been a few threads discussing techniques recently.
Once you have some matched pairs, try a few in your VCO to find the pair that have the best log tracking over the greatest number of octaves.
Looking at datasheets most matched pairs have similar tolerances to what you will obtain with a good matching circuit, plus few address the log tracking parameter (from memory only the LM394 app notes discuss this).
Basically tune your VCO to 440Hz (for example) at 0V on CV input. put 1V on CV observe 880Hz on output, 2V on CV...etc. If the VCO goes out after just a couple of octaves, try another pair.
Except for pedants, the results should be good enough for synth use.
just for fun:
here's four C1583s and tempcos glued to a block for a Quad VCO circuit built by masa921
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fluxmonkey
Joined: Jun 24, 2005 Posts: 708 Location: cleve
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active
Joined: Jan 21, 2011 Posts: 23 Location: Brooklyn, NY
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Posted: Tue Feb 08, 2011 10:40 am Post subject:
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so has anyone found an available replacement? it is one of the few parts i am missing from my build right now and this thread has made me kind of sad about the hopes of finding something. can you order a small amount of chips from THAT? |
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cassiddidy
Joined: Mar 01, 2011 Posts: 2 Location: New York
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cassiddidy
Joined: Mar 01, 2011 Posts: 2 Location: New York
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Posted: Tue Mar 01, 2011 2:52 pm Post subject:
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Sorry, that's for the SSM2212, replacement for the SSM2210 |
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kjackman
Joined: Sep 05, 2010 Posts: 69 Location: Utah, USA
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Posted: Fri Mar 04, 2011 8:35 am Post subject:
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Note that this is a surface-mount SOIC package. You'll probably need a SOIC to DIP adapter to use it. |
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adhdboy
Joined: Feb 16, 2005 Posts: 57 Location: denver
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LFLab
Joined: Dec 17, 2009 Posts: 497 Location: Rosmalen, Netherlands
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Posted: Tue Jul 17, 2012 1:09 pm Post subject:
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Well, it seems making duals still makes sense businesswise for NXP. Not sure if they are a direct drop in for LM394 or SSM2210 (although I do intend to use them as such), but there are matched duals available for 2n3904 (type number eludes me) and there's BC847BS from NXP, they also have a PNP dual BC857BS, and....... they also a variant which is matched, these are the BCM847BS and BCM857BS. I did a layout for them and posted it on muffs: http://www.muffwiggler.com/forum/topic-55387.html
Of course these are all smt parts and small ones at that, found out today that there's a variant in a ever so slightly bigger package which is called BCM847DS, it's only half a millimeter, but at this scale......
The board also has room for up to two smt tempco resistors (because the Panasonic ones are not available in 2k, but are in 1k). |
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