Tweed tone circuit to LTP PI

[phydauex]

I"ve been building a modified 5F4 Super style amp lately and really digging it. I think one of the great things about it is the tone controls, much more open sounding. Anyway, so I thought about mating those same preamp/tone controls to a 5F6A power section (LTP), to get more volume, but get it to break up faster than a typical 4x10 Bassman does, and retain the magic of the earlier tone controls. I got it wired up and wasn't thinking it all through when I got to the input of the phase inverter. The Tweed tone controls direct couples the Treble wiper to the grid of the driver tube in the PI, and in the 5F6A, the Treble wiper connects to a .022 coupling cap.
I guess my question would be does that cap need to be there? Is there any loading issues if I leave the .022 input cap there. Just appreciate any thoughts, observations from those more versed in theory or anyone whose tried that before.
Thanks, Matt

[Chuck H]

There does need to be a cap there to block the 0VDC reference via a resistive path in the tonestack. The LTP PI has it's own DC bias arrangement and outside DC sources need to be isolated from it. You could go with a larger cap to be sure that what the tone stack is saying is what the LTP is hearing. Just use a .1uf cap between the TS and the PI.

[phydauex]

Thanks Chuck, I thought that might be the case. Although, experimenting is always fun, I was going to bypass the cap to see if I got ugly noise or something. I guess the "or something" might be just a big drop in volume. Thanks for explaining it clearly