TSL Clean Channel Problem (sound coming out through with all controls on 0)

[AmpFix]

I have a TSL in the shop from 1999 with a few issues. I've spent a bit of time of this amp fixing bad solder joints and getting the bias circuit to work again. The XLR out circuit seems to be affecting the bias and I haven't had the time to look at that but the customer doesn't care about the XLR out, so I'l just disable it for now.

The amp has 1 problem left. When all controls on the clean channel are at "0", I still get some sound to come through the speakers when playing through the clean channel. The other channels are fine. I tried the test with all controls at "0" on all channels to see if perhaps one of the other channels was bleeding through the clean and it made no difference.

These amps are pretty complex and I could be spending a lot of hours on this before I find the solution, which is why I'm seeking help here. Perhaps one of you has seen this before?

I measured the OPT1 and OPT2 LDR values on the clean channel board and found something interesting.

In clean mode:
OPT01: 241 ohms
OPT02: 261 ohms

In crunch mode:
OPT01: 500k ohms
OPT02: 1.9M ohms

OPT01 seems a little low when in crunch mode but in clean mode, it looks fine, so that's probably not the problem.

Any ideas on what to look for here?

[chipprogr]

ITs been awhile since ive looked at this issue but 'HAD" to fix it for a customer once. Seems inherent in this model of amp. If memory serves me correct, the problem was that one of the blue wires was carrying the preamped signal was lying right along with another blue wire that was very sensetive. It was crosstalk that was the issue. If you started to turn the clean volume up just a little, it actually got quieter until you broke over that majic point and then it did start to get louder like it should. At what should have been no volume, you heard this mid range/hi end bleed through.

THE FIX : replaced one or both of those wires with shielded cable. Seems to me that it was a 3 pin plug, possibly all blue wires.

[AmpFix]

Hmmm, interesting. Is this blue wire going from the clean board to the tube board, or the crunch channel board? There's a LOT of wires in there!