Author Topic: Loud pop noise when engaging Keeley 4-Knob Compressor  (Read 1222 times)

juan_felt

Loud pop noise when engaging Keeley 4-Knob Compressor
« on: September 07, 2017, 01:59:05 PM »
Hi everyone,

I've built a Keeley 4-knob compressor, and it works (and sounds) great, BUT whenever I turn on the effect I hear a (quite) loud POP.

This is the schematic I'm using:



I presume that "R1" resistor is the "pull-down resistor" (is this the correct name?), also, since the output is directly connected to Lug 2 of the volume Pot, there is no need for another pull-down resistor, right?

I tried disconnecting the LED to see if this was the problem, but nothing changed.
If I turn the volume all the way down, and then engage the pedal, there is no "POP".

I'm using the 3PDT wiring that grounds the input of the effect (the one from General Guitar Gadgets).

I will appreciate any help!!!

Cheers,

J

amz-fx

Re: Loud pop noise when engaging Keeley 4-Knob Compressor
« Reply #1 on: September 08, 2017, 07:40:16 AM »
You could lower the value of R1 to 2M2 and see if that helps any.

regards, Jack

antonis

Re: Loud pop noise when engaging Keeley 4-Knob Compressor
« Reply #2 on: September 08, 2017, 07:57:04 AM »
Even down to 1M..
(shouldn't make great difference on input impedance..)

What is the type of C1..??
« Last Edit: September 08, 2017, 08:11:21 AM by antonis »
"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..

Ben Lyman

Re: Loud pop noise when engaging Keeley 4-Knob Compressor
« Reply #3 on: September 08, 2017, 07:51:40 PM »
My Dynacomp clone (pretty much the same thing) had a loud pop too. I used a 2M2 pull down resistor and wired the footswitch to ground the input and output directly in bypass.
The only thing that helped was Jack's "Anti-LED Pop" set up:
http://www.muzique.com/lab/led.htm
Thanks again Jack!
"I like distortion and I like delay. There... I said it!"
                                                                          -S. Vai

juan_felt

Re: Loud pop noise when engaging Keeley 4-Knob Compressor
« Reply #4 on: September 09, 2017, 12:06:13 AM »
My Dynacomp clone (pretty much the same thing) had a loud pop too. I used a 2M2 pull down resistor and wired the footswitch to ground the input and output directly in bypass.
The only thing that helped was Jack's "Anti-LED Pop" set up:
http://www.muzique.com/lab/led.htm
Thanks again Jack!
Hi everyone! Thanks for the replies, I will try both things and see what does the trick! I'll update as soon as I have it ready!

Happy weekend!
Cheers,
J

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