Modifying Inductor-less Coloursound Wah For Bass

[nchauhan890]

I'm planning on building a Coloursound Wah (without inductor) detailed here:

http://beavisaudio.com/projects/colorsoundwah/
(The first, most basic schematic)

Since I wanted to be able to use this primarily for bass, how should I alter the capacitor values?

The in/out capacitors C1 and C7 I presume I should increase to somewhere between .47-1uF. I'm not sure about the other ones, especially the "Twin T" ones. After a bit of researching, I only found mods for the inductor version where the 'sweep' range capacitor was changed. What exactly is the equivalent in this version?

[nchauhan890]

I was also thinking about adding a 100k dual gang pot on the 2 wires that lead down from the collector and base of the transistor to the twin-t section. It would be wired with lugs 1 and 2 and the 3rd jumped to the middle lug. I'm not sure whether this will have the effect I'm looking for: to keep some clean signal and let only some down to filtering. I'm

[mac]

Just increase C5 and C6 a bit.
No need to tweak the in and out caps.

C4 and R7 can be tweaked too.

BTW, R9 should be 330 to 470 ohms.

mac

[nchauhan890]

Just increase C5 and C6.

C4 and R7 can be tweaked too.

BTW, R9 should be 330 to 470 ohms

Hi Mac,
I've seen others have chosen 470 ohms for R9, as you said, which is what I'm going for.

I saw another post of yours where you mentioned you could increase C4 to 22nF instead of 15nF. I'm going to also get a 33nF just to experiment. In terms of changing R7, I'm opting for a B100K pot as detailed later on in the article to act as a resonance control.

With C5/6, do you have any recommendations? I assume that increasing them will give a reduced bass roll-off.

[mac]

With C5/6, do you have any recommendations? I assume that increasing them will give a reduced bass roll-off.

Increase the 2n2 to 4n7 or 6n8 for example.
Breadboard is your best friend.

mac

[nchauhan890]

Thanks for your help, Mac.

I'm going to try a 2n2, 3n3, 4n7, 6n8 and 10n. Hopefully it'll retain some of the lows.