[sdiy] Buchla 257 is an extremely strange circuit

[Chris Muir]

On Dec 16, 2009, at 9:11 AM, mark verbos wrote:

> The PWM solution is very linear and repeatable. It's no so bad, I  
> use a SPDT switch instead of 2 SPST switches. That doesn't help too  
> much, but it's something.


My problem with this whole class of PWM "VCAs" is the bandwidth.  
Generally they are not run at high enough rates to accurately pass  
really sharp transients any too accurately.

Mark's 254 is better than the Buchla 256e in this regard, but if you  
really want to attenuate a sharp envelope to a low pass gate, for  
example, you are better off going through a pot.

- C

Chris Muir
cbm at well.com	
http://www.xfade.com