Maybe I should try a different angle here. I have recently added an Ashly SC-50 to my bobby rig. I have been running it in the effects loop of my Mesa Studio-Pre before my delay (AD-202). From everything I have read this seems like a decent approximation of Bobby's late 70's/early 80's signal path. My question to the forum here is: How does/did Bob use compression?
In reading the Ashly manual it seems like the unit can be set up in one of three ways:
prevention of clipping or excessive peak (short attack 1ms, med release .5, ratio 10 and adjust output to desired max)
loudness enhancement (gentle compression ratio approx. 3, 10ms attack, .1sec release, with enough gain to cause about 6db of gain reduction)
added sustain (Ratio 5, attack 20ms, and a release time .1sec, adjusting the gain to the desired length of sustain)
I am currently splitting the difference between "loudness enhancement" and "added sustain" with settings: ratio 4, attack 15, release .1, with enough gain to push the gain reduction to -6+ and adjusting to output to unity. So far I am fairly happy with the overall "chime" the unit adds to my tone as well as the evenness it gives to my single note lines in relation to full chords.
I haven't had that much experience with compression in the past. So, my setup is based on some trial and error and my best educated guess. If anyone out there has a better grasp of this unit, compression in general, or how Bobby incorporates it into his tone, I would very much appreciate your insight.