Adding / Building a patchable "Sidechain filter" to a real SSL bus compressor.

I'm thinking about adding/building  a "Sidechain filter" ,ala SSC or the like, to a real SSL 4k bus comp. There are a few things to figure out, but my first question is:

Passive vs buffered.

Consider the GSSL sidechains that are out there... The SSC is active/buffered. Is that necessary?  I have no interest in the "THRUST" circuits...

jwhmca said:

I'm thinking about adding/building  a "Sidechain filter" ,ala SSC or the like, to a real SSL 4k bus comp. There are a few things to figure out, but my first question is:

Passive vs buffered.

Consider the GSSL sidechains that are out there... The SSC is active/buffered. Is that necessary?

Click to expand...

It depends what you expect. With passive, you can only get 1st-order response (unless you use expensive and unpractical inductors), so typically 6dB/octave slope; and the range of fequency may be limited. The actual frequency and slope may vary with settings and operation. Going active, you will have more accurate control of parameters and more freedom. [/quote] I have no interest in the "THRUST" circuits...
[/quote] Yet they make more sense than basic HPF's.

Does the sidechain filter need to be buffered? Looking at the SSC schematic it seems the opamps just drive and buffer the signal.

jwhmca said:

Does the sidechain filter need to be buffered? Looking at the SSC schematic it seems the opamps just drive and buffer the signal.

Click to expand...

It is good practice to buffer a passive filter.