Thanks Enzo. I pulled a copy of the Cambridge 30, but didn't even bother with it. I traced the problem right to the opto isolator...which I replaced with a better unit and the amp is alive and kicking.

I just had a a (Korg) Vox Cambridge 15 roll into the shop, but do not have a schematic or service manual for this specific unit. It has very low output and the clean channel is pretty distorted....unless the tremolo trim pots are tweaked, then the amp comes alive for a few minutes and then back to crud it goes. I'm leaning on the thought that the vactrol is shoddy, but would love a schematic/service manual or input.