Tone Bender MkII filtering cap

[yeeshkul]

If i use something like 330uF instead of typical 47uf filtering cap - would it have any influence on the sound?
I want to do it just to help filtering some wall wart noise ...

thanks
Jan

[John Lyons]

You can use it but it may not make a audible difference.
It will help filter the DC smoother but whether you hear it is negligable.
You can try a 100ohm resistor in series with the 9v supply and that may help the filtering, as well as the big cap.

john

[bluesdevil]

If I remember correctly, when I had my ToneBender on the breadboard I tried higher values and it did affect the sound. Either made it muffled or took away sustain.... maybe both. Maybe use a socket if you can, just in case.

[John Lyons]

We're talking about the cap from 9v to ground correct?
This should have no effect on anything but possible hum
or noise from the power supply, no?

john

[yeeshkul]

thank you John, that's what i think, just wanna be sure. The 100R is good idea! By the way i like the Ennio Morricone T-shirt you have on you web

Harmonica: I saw three of these dusters a short time ago, they were waiting for a train. Inside the dusters, there were three men.
Cheyenne: So?
Harmonica: Inside the men, there were three bullets.

[yeeshkul]

one more thing - i checked out this Cry Babe schem. and I see they use 220uF in parallel with 100nF(??) + 1k res. Guys do you have any idea why they connect those two caps together? Can it be just some sort of a subtle adjustement of the filter?

[John Lyons]

Large caps work well to smooth out the power supply but they aren't very efficient at high frequencies.
By putting a smaller (relatively) cap across the larger one you help with higher frequency noise and possible oscillations.
The 1K is staving the current and giving the circuit a little less power.
With a 47 or 100 ohm resistor you are helping with noise but with a larger resistor you start to change the way the circuit sounds.
With op amps some people find the circuit "sweeter" or "brown".
You can hook up a 5K pot and play with starving the circuit. Zvex, Joe Gagan, and others use this as a panel knob.

john

[yeeshkul]

thanks again John! everything clear now.