fixed resonance > depth control

[Smokebreak]

I just put in fixed resonance in a 3stage + CF 6V6 Marshall type.
8ohm tap>220k//2n2>47K>5Kpresence/.1u
I really dig it, but want to put it on a pot for various degrees of the low end thump insertion. I'm trying to figure out what's going on with the fixed resonance though, in theory.
Is it basically a high pass that limits bass in the FB loop, so that bass is not attenuated in the loop?
Seems the common depth mod on a pot is .0047 on a 1M pot. Seems to me like .002 on a 500K would serve my purpose, but I've never seen that. Then again, I'm not sure what the effect will be of changing the resistor value vs. changing the cap value, or what I can expect with the value changes. I'm gonna fiddle with it but I'd rather approach it with a little bit of sense of what I'm doing

[Jana]

Change the 220K to a 250K pot.

[martin manning]

Is it basically a high pass that limits bass in the FB loop, so that bass is not attenuated in the loop?

Exactly. Maybe try a Presonance control and see if that works for you?

[Smokebreak]

Is it basically a high pass that limits bass in the FB loop, so that bass is not attenuated in the loop?

Exactly. Maybe try a Presonance control and see if that works for you?

Ok I think I see.. lower value cap in the RC for fixed res will produce more bass in the end, and lower value resistor will do the same...I think..

I had the presonance in this amp when I built it up a while back, and it worked great! i think I pulled it because I just wanted to hear all the different NFB circuits. I may just need to reinstall that.

I'm thinking I'm going to try putting the variable depth control on a switch, so I can take it out of the circuit if I want. Or is that redundant? I keep reading that turning the depth all the way down takes it out, but isn't there still a cap between OT and feedback resistor?