Marshall Super Bass Preamp Pedal Treble Channel Only Works At Max Gain

[freshmex18]

Built this Marshall Superbass Preamp pedal


https://tagboardeffects.blogspot.com/2018/10/marshall-1992-super-bass.html

I used the first option with a switch to go between the two channels but I have not installed the switch yet.  Tested the pedal by alternating the Treble and the Bass input wire into my testing pedal rig.  Bass channel works fine.  Treble channel only works if Treble Gain is at max.  Turn the knob a hair to counter clockwise
and signal cuts out completely.  Anyone know why?

The only subs I made for the circuit are

560p cap for the treble channel bright cap

Instead of 320uF caps, I used a 100uF and a 220uF since that was all I had

Bass pot is 500k instead of 1M

Treble pot is 500k with a 510k resistor across lugs 1 and 3 to approximate 250k








 

[FiveseveN]

Schematic
please

[freshmex18]

It's just the amp schematic using J201s instead of tubes

https://schematicheaven.net/marshallamps/jmp_super_bass_100w_1992.pdf

[PRR]

Treble channel only works if Treble Gain is at max.  Turn the knob a hair to counter clockwise
and signal cuts out completely.  Anyone know why?

Cracked pot.

[freshmex18]

My reactions to "Cracked pot" comment in the order I had them

1. Why is he calling me a crackpot?
2. Wait, no it says "cracked pot."  What is a cracked pot?
3. Wait, he means the pot is broken.  It can't be that.  It's always something on the board that is the problem.  It wouldn't be something that simple that is wrong.
4. [Changes pot and it works] Why didn't I consider the pot as the problem? 
5. I am so so stupid

Long way of saying "problem solved!"