Its a good idea but I would be suprised if you could take the control of the ssl and sub in any 'ol control circuit in there. Its a good idea I certainly dont know enough about this stuff to contribute anything beyond that...
Were there to be another revision of the gyraf ssl boards, I think a fine step (however a complete redesign) would be to add the following:
-power supply with 317s for variable voltage output.
-discrete audio path with "standard" pin footing for user choice of common gain blocks.
-space for input transformers on board
-pads for mounting output transformers off board
For my two cents, the most important improvement you could make to any project would be getting the chips out of the audio path. I would bet that the very smoothing quality that the ssl compressor has is very much a result of the opamps selected for audio, by making this change to a discrete audio path, you'd really be building a very different, likely more aggressive sounding box. With those improvements, youd be able to vary the power supply, so you could chose whatever opamp you wanted to use. You could chose a variety of input transformers and output transformers, so with a revision, you could make a box where 10 people could build it and wind up with 10 different sounding boxes, all of which whill probably sound different than the current gyraf design. I think it would be worthwhile to do but I suspect its a total redesign. Shame Im the electronics 'tard, or I would design the thing myself for everyone, all I have is a war plan, no army...
Is this of interest to anyone else?
This is probably a pretty good format to follow for all of our group projects in the future if you think about it. Take a look at the boards joe did for the JLM99 pre, you could build just about anything on those boards. By incorporating a variable supply and the gain block footprint, you more or less open up any project from one particular thing to several options which of course will appeal to a wider group of people, etc.
I would definitely use the ssl quad more if it had a discrete audio path, everything else in my studio is discrete and that thing tends to stick out like a sore thumb in a mix, which is both really good and not so good all depending.
dave