Footswitch popping chaos

Started by JuanLennon, March 05, 2018, 11:07:21 PM

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JuanLennon

I recently finished building my first pedal, a bazz fuss - based on the build from tonereport. It has worked great the past few days, but tonight the footswitch started popping occasionally when I'd switch it off. When the pedal pops it causes my delay, which is next in line, to go crazy. The delay, which is a digitech digidelay (not sure if that makes a difference), at first makes a high pitched hissing which then turns to a static white noise type sound and won't work right unless I unplug it and plug it back in. Can anyone shed some light on what the heck is going on?

antonis

#1
Probably your delay is "latched" due to some supply disturbance (those digi-migi-tigi-wigi pixies inside them .. :icon_mrgreen:) caused by a very leaky capacitor..
(check on output for some tens of mVDC or so..)


If your Buzz Fuss output capacitor is placed AFTER Vol pot, it should be grounded via stomp switch (on by-pass setting..)


And of course, Wellcome..!! :icon_biggrin:
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

JuanLennon

Thanks for your reply Antonis. If a leaky cap in the bazz fuss is the culprit, would a pull down resistor fix the issue?

antonis

#3
Quote from: JuanLennon on March 06, 2018, 09:09:06 AM
If a leaky cap in the bazz fuss is the culprit, would a pull down resistor fix the issue?
It depends on how much leaky it is..
The more leaky the lower value resistor needed, finally resulting at "direct" grounding..
(with all unwanted issues..)

Pull-down resistor doesn't cure popping caused by DC voltage leak greater than about 10mV..
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

JuanLennon

Thanks again Antonis. What do you think the best fix for this is, if there is one?

antonis

#5
It depends on actuall problem source..  :icon_wink:

The easiest fix is grounding In + Out via 3PDT switch..
(you do use such a switch, don't you..??)

Here is a way for doing it - right corresponds to - possible- LED popping cure..
(there are also other wiring combinations with same result..)



IMHO, you better measure OUT DC offset 'cause a heavily leaky cap may result to other issues, like following Pot scratching..

P.S.
I've tightened a bit Ron's loose wiring, cause copper is costly and some of us aren't as wealthy as Ron.. :icon_wink:
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

Kipper4

Has the op tried replacing the leaky cap yet?
Ma throats as dry as an overcooked kipper.


Smoke me a Kipper. I'll be back for breakfast.

Grey Paper.
http://www.aronnelson.com/DIYFiles/up/

antonis

I suspect he didn't even verify it.. :icon_frown:
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..