i play through a late seventies 135 watt series fender twin. given my style of music, i use lots lots of reverb, distortion and treble. let's say i'm tinkering around in the 'verb channel (which i'm always in since i need reverb) with the volume down and i'll come up with a great tone involving my big muff and equalizer. however, when i turn the channel volume past 3, it starts to sound muddy and awful, and then overdrive starts to seep in, making a horrid banging noise, so the tone that sounded so great on lower volumes (or really any distorted signal) is ruined when it's louder. anyone have any suggestions?
Is it just the reverb unit not being affected very well by the distortion and high treble perhaps?
may have to have a look at the reverb can ?
otherwise im stumped
When was the last time you had your twin retubed, more specifically the preamp section ?

Does it happen only when the reverb is on ?
On both channels ?

If yes/yes, try replacing:
- the 12AT7 labelled V3, and,
- the 12AX7 (also known as a "Fender 7025") labelled V4.
Don't worry about bias, this isn't the power section.

If that doesn't fix it, the reverb driver tranny TR4 went out for lunch, and that won't be cheap.

Otherwise, try replacing
- the 12AX7 (also known as a "Fender 7025") labelled V4, and,
- the 12AX7 labelled V5, and,
- the 12AT7 labelled V6, and,
- the 12AX7 labelled V1, and,
- the 12AX7 labelled V2