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

[mark verbos]

Aaron,

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
>