are either of these filter designs producing a similar sound to the ssm filter?
What is this SSM filter you’re talking about?
Which circuit?
The chip in itself doesn’t have any sound. The circuit around it defines the sound.
pardon my misunderstanding- yea i thought that the 4p or the smr 4 was a similar sound to the SSM? or are neither related?
The SSM2040 is just a bunch of gain cells. They don’t have a specific sound. What is responsible for the sound of a filter is the circuit the chip is a part of. One could build completely different filters with the same SSM chip as its core.
That’s why I am interesting in knowing which synth you are interested! When you mean “SSM sound”, you have specific synths in mind. That’s what I want to know… Because I’m pretty sure the SSM chip has little to do with the sound of these - more the filter topology and choice of components around the chip…
ok i’ll shoot- prophet 5 rev 2?
or korg polysix 
and ppg !
Get SMR, do not solder C22.
thank you
That’s interesting !
Pichenettes how would you describe how this modification impact on the sound of the filter, and do you have any other suggestions that would modify, in a pleasant way, the sound or behaviour of the SMR4 filter ?
thanks for sharing 
> Pichenettes how would you describe how this modification impact on the sound of the filter,
It makes the sound goes weaker and weaker as resonance is increased (and as a side-effect, allows a very pure and loud self-oscillation “tone” to grow on top of the signal). That’s a “feature” of the 3 synths mentioned above.
Another mod would be to change signal levels - halving R25, R21, R3 and R7 ; and doubling all 1nF caps.
Sorry for necroposting…
How about the Kawai sx-240?