[sdiy] lots of VCAs on one PCB

[Jason Proctor]

another option is an Arduino mega (16 ADCs) with a nice SPI DAC.



>Joergen Bergfors did a "VCA Shootout" page, that gives a few options 
>for VCAs and other performance figures.
>
>http://hem.bredband.net/bersyn/VCA/vca_shootout.htm
>
>Arguably if you went SMT you could do nigh whatever you wanted, 
>though if you want to stick with through hole, this looks to be the 
>smallest area with best performance:
>
>http://hem.bredband.net/bersyn/VCA/ssm2024%20vca.htm
>
>Per one set of SSM2044 and TL074 = 4 VCAs, with only 4 resistors and 
>one cap per VCA. Even with power connectors and bypass caps, that's 
>still pretty small.
>
>
>_Kyle
>
>--- On Mon, 11/23/09, Derek Holzer <derek at umatic.nl> wrote:
>
>>  From: Derek Holzer <derek at umatic.nl>
>>  Subject: [sdiy] lots of VCAs on one PCB
>>  To: "synthdiy DIY" <synth-diy at dropmix.xs4all.nl>
>>  Cc: "Derek Holzer" <derek at umatic.nl>
>>  Date: Monday, November 23, 2009, 4:13 PM
>>  Howdy all,
>>
>>  I'm looking at building a joystick controlled 4x4 matrix
>>  mixer, which requires 16 VCAs when it's all added up. It
>>  would be for control voltage, so a linear VCA is required.
>>  I've looked at the Thomas Henry VCA, which is pretty simple
>>  and quite nice, but all the layouts I've found for it are
>>  fairly large.
>>
>>  It struck me that a vocoder would need approximately the
>>  same amount of VCAs (depending on the number of
>>  analysis/resynthesis channels of course), so there must be
>>  some layout someplace that has a lot of VCAs packed together
>>  on one PCB board.
>>
>>  Can anyone point me to a layout that packs so much into a
>>  fairly small space (one Eurocard sized PCB 100x120mm)? Or a
>>  super basic linear VCA schemo that could be laid out in such
>>  a way? Alternately, is there anyone interested in working
>>  with me to design such a thing? I'd be willing to invest
>>  something in getting PCBs made in this case.
>>
>>  Best!
>>  Derek
>>
>>  --::: derek holzer ::: http://blog.myspace.com/macumbista ::: 
>>http://www.vimeo.com/macumbista :::
>>  ---Oblique Strategy # 118:
>>  "Make what's perfect more human"
>>
>>
>>
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>
>
>      
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