1974 JMP 50 with removed 500pF cap

[Pete Farrington]

Your rationale doesn’t make sense to me, but at least you’ve made your decision in the light of understanding what the scenario is

input 2 is still dull and bassy and pretty much unusable on its own

That will be most pronounced with Volume 1 turned to minimum. As its turned up, the filtering effect is negated somewhat, and channel 2 gets brighter. This is without anything plugged into channel 1.
The downside being the hiss from channel 1.

 

[gelsmander]

As its turned up, the filtering effect is negated somewhat, and channel 2 gets brighter. This is without anything plugged into channel 1.

Thanks, I knew about it working the other way round but this didn’t cross my mind. Not that using channel 2 alone would be necessary, but good to know.

Either way, I’m happy with how the amp sounds now and the bright caps should give me the flexibility to tweak, if I end up needing that.