adding tone control to pedal

[nognow]

I want to add a tone control to the wet signal of the boss ce-2 (http://www.tonepad.com/getFile.asp?id=101)
what is the easiest way to do so?

[antonis]

Hmmm... Easiest way..??

Connect a 6n8 cap between left side of R21 and GND and a 100KA pot (wired as variable resistor) in series with a 1k5 resistor between R21 and C4/R6/C5/pin7...

( I didn't make detailed frequency calculations for gain loss but a range of 0.3 to 1 seems OK... )

edit: I've just noticed that you may obtain same results with C15 and R23 combination..

[nognow]

Hmmm... Easiest way..??

Connect a 6n8 cap between left side of R21 and GND and a 100KA pot (wired as variable resistor) in series with a 1k5 resistor between R21 and C4/R6/C5/pin7...

( I didn't make detailed frequency calculations for gain loss but a range of 0.3 to 1 seems OK... )

edit: I've just noticed that you may obtain same results with C15 and R23 combination..

I accidentally gave the wrong schematic(for some reason thought they were identical)...
here is the actual one :http://www.tonepad.com/getFile.asp?id=101

[antonis]

O.K.

R23 and C15 form a low pass gain of 2.3kHz for BOTH signals so dry signal is "restricted" by this..
(actually it's attenuated by the 10k/47k ratio)

You can form a tone control for dry signal between R21 and IC1a out in the way of former description but you'll have to make calculations for a range of 2k3Hz and what comes out of C4/R6 (33.3kHz) and C3/R5 (2.3kHz - whitch is the same as R23/C15)

If I've made right calculations, you have NO room for tone control..
(or maybe I need a cup of strong coffee.. )

[GGBB]

If it's to be on the wet signal only, best and easiest place to do it would probably be in the low-pass filter section just before Q3. There are several things you can do in there with R16, R17, R18, C11, C12, and C13 such as different variations on the Stupidly Wonderful Tone Control. If you don't want to change what's there, add a cap in series with a pot wired as a variable resistor (jumper pins 2&3) between the wet signal and ground. You'll get different results depending on whether you connect it after R16, R17, or R18, and of course depending on the cap value - so experiment. For the pot I'd start with a 100k log, and for the cap try 22n. This is a shelf-style control to reduce treble only. If you want a more traditional tone control or want to both brighten and reduce, you'll need to do something a little more complicated, such as AMZ's SWTC-3 (below).

[nognow]

If it's to be on the wet signal only, best and easiest place to do it would probably be in the low-pass filter section just before Q3. There are several things you can do in there with R16, R17, R18, C11, C12, and C13 such as different variations on the Stupidly Wonderful Tone Control. If you don't want to change what's there, add a cap in series with a pot wired as a variable resistor (jumper pins 2&3) between the wet signal and ground. You'll get different results depending on whether you connect it after R16, R17, or R18, and of course depending on the cap value - so experiment. For the pot I'd start with a 100k log, and for the cap try 22n. This is a shelf-style control to reduce treble only. If you want a more traditional tone control or want to both brighten and reduce, you'll need to do something a little more complicated, such as AMZ's SWTC-3 (below).

I may have found a cheat...if you go down to the second page of the schematic you'll notice a possible effect level pot(dry/wet mix) so maybe I can simply put a tone circuit right before the pot?

[GGBB]

I may have found a cheat...if you go down to the second page of the schematic you'll notice a possible effect level pot(dry/wet mix) so maybe I can simply put a tone circuit right before the pot?

A simple variable low pass RC filter (i.e. tone control) requires series resistance followed by capacitance to ground. If you put this right before the effect level pot - which is right after C14, the series resistance will lower the level of the wet signal. If you keep that extra series resistance constant, you can compensate for the level drop by adjusting R22 accordingly, but you may run into problems anyway with the dry signal being affected since R21 and R22 are merely a passive mixer for the two signals - but it might not be enough to notice. By placing the tone control before Q3, it is buffered from the dry signal. And since that portion of the circuit is already filtering out highs, I'd argue that it's a more logical choice for a wet tone control.