Hey all,
As always, excuse my layman's terms in the description. Since the T40 has fairly unique circuitry, I'll try to include as much as I can in the problem description without getting too crazy.
My '81 T40 has this issue where the Bridge pickup has a severe drop off in Volume & Tone when I roll full on to 10.
If I back it back to 9 or so, all is good.
This only happens when I have both the Neck and Bridge pickups active (selector switch in the middle) and the Neck pickup at 10.
If I solo the Bridge pickup, it tapers nicely from 0-10 and back down.
If I solo the Neck pickup, it also tapers perfectly.
The phase switch (in-phase/out-of-phase) doesn't affect this issue.
The T40 has a pretty unique Tone circuit where you can put each pickup in a Humbucking mode (0-7) or Single Coil mode (7-10) by rotating the Tone Knobs.
I don't know how much (if any) complexity that Tone circuitry brings into the mix, but I thought I'd bring it up.
This issue occurs regardless of the position of either Tone knob.
I thought I'd look for an answer here first.
Thanks,
Steve