[sdiy] Later MS-20 filter with 2164

[Antti Huovilainen]

On Thu, 1 Jul 2010, David G. Dixon wrote:

> http://www.timstinchcombe.co.uk/synth/MS20_study.pdf
>
> From his analysis it would appear that the diodes do very little in the
> later filter, but are very important in the early filter.

Not quite. In the first filter version the diodes are at the output of the 
filter from where the signal is sent to the first capacitor and the VCA. 
In the second filter the diodes are only in the feedback path. They are 
still important in getting the right resonance sound (as they clip the 
feedback signal). The effect also depends heavily on the input signal 
amplitude.

Antti

"No boom today. Boom tomorrow. There's always a boom tomorrow"
   -- Lt. Cmdr. Ivanova