Peavey T40 volume drop off issue: any clues?

[ack1961]

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

[exiledarchangel]

When 2 passive pups are on 100% at the same time, there's always some signal cancellation and the sound becomes alittle hollow, maybe its that?
Try to adjust the height of the pup, that could help up to some degree. Else I would check wiring, maybe the 3way switch contacts need cleaning or there is a cold solder somewhere.