Damn Pedal Pop

[casperh7]

This is really beginning to annoy me: why do some pedals make a really loud pop when you engage them? Likewise sometimes when I'm switching an amp off it pops too? Why?!

C

[timmyo]

Google 'dc offset' and for a possible fix google 'pulldown resistors' (I don't understand well enough to explain properly myself, but them's the phrases that'll come up in the answer

[Dadave]

With amp on standby, click pedal about 10 times. It wont do it then

[ICBM]

Replace all pedals with Boss/Ibanez/Digitech etc with proper electronic switching: problem solved.

Put amp on standby before switching off. (OK, they sometimes still pop when you turn the standby switch off too.)

Solid state amp/amp with no standby switch: that's probably just the way it is. It doesn't cause any harm.

[Sporky_McGuffin]

As Tim says it's a DC offset in the pedal (almost always using mechanical bypass) - could be that the decoupling caps are dying, could be that they don't have bleed resistors, could be lazy TB wiring. Theoretically it can even be noise caused by the LED turning on and off (though I've never experienced that problem).

[frankus]

Sporky, how did you win the game?

[ICBM]

It can also be caused by DC leaking from the amp, usually from the input valve of a valve amp. You can isolate whether this is the cause by running a buffered pedal between the amp and the pedal that pops; if it stops, the problem is the amp.

For what it's worth, today I modified an amp for a customer by fitting a standby switch, exactly to fix the amp-pops-when-turning-off problem... although this isn't related to making pedals pop.

[casperh7]

some amps don't do it, although my Matamp gets REALLY hot after a while of playing. Is there a 'quick fix' for the pedal pop?

C

[Sporky_McGuffin]

Sporky, how did you win the game?

By adopting this new signature. Easy, huh?

[ICBM]

Is there a 'quick fix' for the pedal pop?

'Quick' fix, yes - run the problem pedal in the loop of a Boss LS-2 or NS-2. Not the cheapest or least space-invasive solution though...

Adding bleed resistors across the circuit input and output can fix it, too.