LPF/Tone control for feedback pedal?

[big bustle]

i've wired a simple RC tone control/lpf into my feedback pedal circuit.

the send runs into the center lug of a 250k pot. the 3rd pin/outer lug connects to the return and to a .01uf cap connected to ground. the first lug of the pot is not connected.


the problem is when the tone control is up i.e. turned fully clockwise it still is affecting the feedback a bit.

is my math wrong on this rc circuit for this to function the right way?

should i change my values?

i happen to have a ton of 100k pots i'd like to use for this build. i was sticking to 250k and .01uf because i happen to have them handy


i was looking at guitar tone wiring diagrams and a lot of these don't seem to be wired in the way that RC circuits are.

for example:

http://www.guitarelectronics.com/product/WD1H11_00/Guitar_Wiring_Diagram_1_Humbucker1_Volume1_Tone.html

the tone is tapped off the volume and the output you would normally see before the cap is not used like here:

http://www.muzique.com/schem/filter.htm

so to sum up i would like a low pass filter that can be bypassed when the pot is maxed out and doesn't affect the rest of the feedback circuit.

[big bustle]

i wired up the tone circuit like on a guitar amp

taping off the signal going into a pot connected to a cap to ground.

however i worry now that when my feedback loop is disconnected the tone control will still affect the pedals connected to the loop as im using an spst switch to activate the feedback loop.

can i do this another way with out moving to a dpdt?

[big bustle]

so i tried the "ad a tone pot to any pedal" concept on beavis' site

it worked as expected but it wasn't the low pass filter i was looking for and it attenuated the feedback loop too much to be useful.

so my next idea was to try something like this:



i don't know what the pot value should be. me thinks its going to have to be something very high.

i'm also not sure what the values of r1 and c1 should be

i'm thinking i don't actually need r1 if i wire the pot correctly.

my attempt here is to blend between a simple low pass RC filter and a clean path for the feedback loop