Pedal Popping

rthryhorysak · March 12, 2015, 07:57:52 PM

I built a rat clone for a friend with a 4 band gyrator eq and hardwired lpb-1 and there have been no problems with popping for the past month, but recently he said that there was loud pop when he turned on the pedal. I am unsure as to why this is happening because it has been fine for a while, and it only started up until now. So iff someone could help I would greatly appreciate it. Thanks.

FUZZZZzzzz · March 13, 2015, 05:26:23 AM

99% of the people on this forum probably know more about this than I do, but the popping could be the result of a couple of things.

If you havent already, search for pulldown resistor in the search menu. This will, most of the time, be a good cure. But not always.

snarblinge · March 13, 2015, 06:00:05 AM

http://www.muzique.com/lab/led.htm

Until I implemented the 2nd option on here, I was plagued by the pop, esp, when combining circuits. I never use pull downs unless the circuit has them in there already, I think I'm using 33uf caps most of the time.

Good luck

Bill Mountain · March 13, 2015, 08:19:47 AM

First I want to say that your pedal idea sounds awesome. I'd love to see the schematic and finished build.

The LED thing is something definitely work exploring.

What has helped me in the past is 2 things:

1. Over engineering the input and output. I mean using pull down resistors and high quality caps on the front and back to avoid popping due to leaking DC.

2. Using a buffered bypass which also has the over engineered input.

I have also noticed on my high gain pedals (like my Bluebeard) the popping is only loud the first time and when the gain is set super high. I guess the first time thing has something to do with leaky caps building up over time and the high gain thing has something to do with the pops volume being boosted by the pedal.

diydave · March 13, 2015, 08:22:31 AM

Where the wire goes to FX-in, I add a seccond wire and link it to the free point at the "led"-side and connect it to the free point.
So when fx is in bypass, the fx-input is kept to ground via the switch.
When you engage the fx, there's no difference in potential of signal and fx-input, and thereby no pops.
Used it with succes in many types of distortions (fuzz, ocd, ts, etc...).

Bill Mountain · March 13, 2015, 08:30:47 AM

Maybe if it is an LED issue you could simply always leave it on and connected to ground but in bypass use a resistor that keeps the current low and the LED super dim and then when engaged just parallel a smaller resistor to increase the current and turn on the LED. Like 22k in bypass and 4.7k when engaged.

Just a thought. I'd need to experiment.

You may still run into problems with the inrush of current.

There are also flip-flop circuits and relay bypass circuits that are silent.

duck_arse · March 13, 2015, 09:38:31 AM

Quote from: rthryhorysak on March 12, 2015, 07:57:52 PM
I built a rat clone for a friend with a 4 band gyrator eq and hardwired lpb-1 and there have been no problems with popping for the past month, but recently he said that there was loud pop when he turned on the pedal.

ask him if anything in the chain has changed or been added/subtracted/moved. some commercial pedals with buffers don't include pull down resistors, so they provide a capacitor just waiting to add pop. I think R.G. has explaned/expanded on this in a similarly titled thread.

rthryhorysak · March 13, 2015, 11:06:59 AM

I asked him if anything had changed in his rig, but he said no and it just started happening one. I don't know if this means anything, but I had him unplug from the input of the pedal to test it as well and it still popped

rthryhorysak · March 13, 2015, 11:09:29 AM

Quote from: snarblinge on March 13, 2015, 06:00:05 AM
http://www.muzique.com/lab/led.htm

Until I implemented the 2nd option on here, I was plagued by the pop, esp, when combining circuits. I never use pull downs unless the circuit has them in there already, I think I'm using 33uf caps most of the time

Thanks you I will try this out when I get the pedal back

MrStab · March 13, 2015, 12:10:37 PM

just to take the "changes in gear" thing an extra step: have there been any drastic changes in the settings your friend used on the pedal itself? did you initially test for pop at extreme settings?
if the problem's just started happening, then i'd round that down to either external gear changes, internal parameter changes or a cap failing. as the other guys said.

JerS · March 14, 2015, 11:02:29 AM

Since it has just started happening, and the person says there has been no changes in gear - could it be a solder joint on the pulldown has gone bad? It sounds strange, but I have seen this - especially here in Canada where the seasons (summer winter) cause expansion and contraction in everything. Maybe found a weak joint. Easy fix - relow the solder.

rthryhorysak · March 15, 2015, 12:58:19 PM

So new development, It' not the led. I disconnected the led and and it still popped. I also re soldered the the pulldown joints as well as any other dull looking joints and still there is a popping. I assume its the capacitors leaking because when I disconnect the power, it still pops, but after a few more stomps the popping goes down considerably. Any suggestions?

rthryhorysak · March 15, 2015, 12:59:30 PM

New 3PDT?

drummer4gc · March 15, 2015, 01:10:03 PM

Quote from: rthryhorysak on March 15, 2015, 12:59:30 PM
New 3PDT?

Try it. I think the quality control on the standard 3pdt is suspect, and I find that some pop more than others, especially if heat was applied a little too long when soldering it. Make sure to tin your wires, lay them out in a way that makes soldering easy and quick, and actuate the switch so that you aren't soldering engaged contacts (can't help the middle tabs, of course.) Might help!

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Pedal Popping