Peavey Deuce/Mace Phase, no phase

[drewl]

Repaired and re-furbished one of the VT series Deuce, but phase doesn't work.

U13 is switching properly, color pot just changes amplitude of signal

I have signal through the delay line U7 through U10, but.... no LFO from U11 and U12.


I know they are both bad as I subbed them into U14's spot and they kill the signal.

Funny, while probing with scope I accidentally shorted U11 pins 6 & 7 and the signal "phased"

No sweep, but a phased sound to the note, shorted the pins again with a resistor and the pitch of the "phase" changes.

Pins 5 & 6 are at -16v rail, when signal was "phased" output pin 6 changed to ~ +3v

Ooooh! found a couple PV 3080's here at work! Hopefully they work.

[drewl]

And just to follow up, replaced the two bad chips and we have phase!

[Enzo]

Glad we could help.

[drewl]

Spiritual guidance!

And I found the schematic here, so you did help.

Sometimes it helps to just talk things out.