[sdiy] Groupbuy for THAT300/320/340/2180B (Current list)

[Aaron Lanterman]

Whoops - that was a typo. Below when I wrote "VCA" I meant to type "VCO" 
(I'm doing VCO lectures next week in my synth class which is why they're 
on my mind). - Aaron

On Sun, 10 Sep 2006, mark verbos wrote:

> Just to be a stickler for detail, there is no Buchla VCA that uses an NPN 
> pair and a PNP pair. The 200 series VCO cores are based on a discrete OTA 
> made from these, but the 110 VCA uses only a single NPN pair and the 292 
> lopass gates use Vactrols. Later Buchla systems used CEM and SSM VCA's.
>
> One could replace the 3080 in most VCA's with a discrete OTA made form the 
> 340, but I don't know how much would be gained.
>
> Mark
>
> Aaron Lanterman wrote:
>> 
>> While we're talking about 340 applications, you can also make a 
>> roll-your-own OTA current switch for a Buchla/Bergfotron style VCA core.
>> 
>> If curious what advantage the 340 would have over using, say one SSM2210 
>> and one SSM2220.
>> 
>> - Aaron
>> 
>