how to fix loud popping on guitar pedals?

booker · audio school Joined: 02 Nov 2009 Posts: 4

I looked through all the DIY posts and didn't find this so here goes and i guess it's not difficult:

how do I solve the loud 'popping' when i push the button on my guitar pedals? BTW: the units are relatively new as well. A Fulltone Supatrem just started in on me and the DOD A/B box has ALWAYS been noisy. Impoossible to use in session but the Fulltone is important.

I've blown out the dust inside with some compressed air but that didn't seem to help.

thanks,
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Booker-

iMac (G5),Protools 8

AstroDan

http://www.geofex.com/Article_Folders/box_pop.htm

This may explain a little. I imagine one of the many good pedal gurus out there would be able to fix this.

I'm surprised your Fulltone is doing this...
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"I have always tried to present myself as the type of person who enjoys watching dudes fight other dudes with iron claws."

suppositron

lyman

Can popping be a byproduct of passive true-bypass switching?

suppositron

AstroDan

suppositron

UnlikeKurt

Depending on the current draw of your LED, when you step on the switch the instantaneous added draw to the LED can cause the pop.

anticpunk · alignin' 24-trk Joined: 29 May 2007 Posts: 52

I've built a bunch of pedals, some with pulldowns and some without, all mechanically true bypassed, and i've found that the pop has a lot to do with the switch itself and not so much the topology or implementation of the circuit.

Been along time since I read the geofex articles, but the pop is a build up of static electricity likely caused by the mechanical actuation of the "stomp" switch. The 1m pulldown resistor gives the static a path to discharge rather than entering the pedal circuitry. The input cap blocks DC but if its an older pedal and the cap is electrolytic, replace that too as precaution though it's not likely the cure for the pop by itself, really would depend.

Clean or replace your switch, check for and add the pulldown resistor and you should be fine from there.

If that doesn't do it, you could implement FET switching, switching using a 4066 Quad Bilateral chip, a MosFET controlled rellay, or the bypass system that Geofex outlines.

-Jay

Andy Peters