[sdiy] Discrete blackmer vca

[mark verbos]

Another cool thing about them is that they are exponential without any converter. Early Serge VCAs were a version using 4 transistors and a dual opamp. I have the DBX 202 and 200 schematics if you want them. Both of these seem to be simpler than what you have going there. I'm not sure about sound quality on these. I know both Serge and DBX switched to THAT corp ICs later on.

Mark




On Feb 11, 2012, at 2:29 AM, James Patchell wrote:

> Anybody here experiment making Blackmer VCA's from discrete transistors?  I know it has been done.   I am pretty sure Hearn Morley does or will sell a discrete one in a module.  I thought it might be fun to experiment a bit with them.  Kind of the cool thing about them is that they take an input current and produce an output current with a gain that is controled by a voltage.
> 
> For those who may not know what a blackmer vca is, here is a link to a prelim schematic of a very basic (and descrete) BMvca
> 
> http://www.noniandjim.com/Jim/SMB2/SMB2.html
> 
> -Jim
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy