Gain Pop....causes??

Strange - this would more likely be a pot issue. Pots can be quite variable in relative change for a given rotation at the very lowest end of their scale. It is quite possible that accuphase C200 came with different pots throughout their manufacturing life or an old pot may have been replaced at one stage (these things are mechanical so eventually they get dirty and are no longer smooth so they tend to be replaced).

Shadorne...thx for the reply...The C200 before the BG upgrade was "normal" 10 o'clock. My tech did the recap and cleaned everything...pots,PCB connections...ect. The only thing I can think is my VAC 140's are burning in and with about 50 more hours maybe things will normalise. The Nichicon Muse C200 didn't change that much but the BG so far has popped a good deal. I experienced some gain pop when I replaced the coupling caps in my dac...Wimas to Mundorf M-supremes...interesting.

I looked up the specs on the output of the C200...2.0V 200ohms at rated output. I have looked for the specs on the VAC 140's but no info yet. I seem to recall there should be a 10 to 1 ratio....any thoughts on the output ratio VAC140/Accuphase C200....