[sdiy] VTL vs. H11F (was: Which is better as a VC resistor?FETor BJT?)

[mark verbos]

On Jul 2, 2011, at 12:46 PM, David G Dixon wrote:

>>> You could build one with BJTs too. See Korg MS-10/MS-20.
>> 
>> Yes.. but you wouldn't WANT  to, because (if you are 
>> referring to the VCA) you need 'selected' transistors, and 
>> also I think that is where the noise comes from. It's a very 
>> ingenious VCA, but.... it isn't what one wants, really.
> 
> Well, the noisy VCA is what gives the MS-20 it's distinctive warm sound,
> IMHO (after playing with a friend's original, mostly for the purpose of
> comparing its filters with mine).  So, perhaps it is what you want if you're
> going after that sound.  However, there are so many superior chips available
> for making virtually noise-free VCAs that I'm not sure why we're bothering
> with this.


I wasn't bothering with the VCA. I was talking about the earlier filter, which is a sallen-key just like a lopass gate but the Korg 35 chip is made up of BJT transistors.

http://www.timstinchcombe.co.uk/synth/korg.html


Mark