Peavey Classic 50 Master Cap

[plexi50]

I have bypassed the FX Loop and wired straight to the tube
The amp works great
The .1 cap is still in line from the master pot and to the tube
The .1 cap is no longer needed (shown in green box)

Question:
Is the .1 cap damping the master volume?
I would replace the cap with a 100k resistor

I would just dig in and see what the difference is but i dont have time to do this right now

[plexi50]

Tried 100K. Too grainy and brittle. Put the cap back in and all is smooth again