Author Topic: Is there any pcb layout for a Mxr Dynacomp with no switching POP noise?  (Read 643 times)

Atodovax

Hello everyone, is there any layout out there for a MXr Dynacomp compressor with no "POP" en swtich is pressed? It seems every layout on the web has the same problem

roseblood11

It's not the layout, that causes the problem... ;-)


Atodovax

It's not the layout, that causes the problem... ;-)
Well i dont know what else to test.. Do you have any ideas why is it poping?

bluebunny

The original design appears to have no pull-down resistor.  If there's voltage on that input cap, you'll get pop.  Fit a resistor.  RG suggests 4M7 in his write-up.  Anything "big" will do.
  • SUPPORTER
Ohm's Law - much like Coles Law, but with less cabbage...

roseblood11

Show us the layout and the schematic, that you are actually using, and we can help you.


Mark Hammer

I suggested "pedal ventriloquism"...and I meant it.  When a true-bypass pedal is plugged into an e-switched pedal, the true-bypass pedal may function absolutely pop-free on its own, but produce a pop in the next pedal because it momentarily disconnects and reconnects the input cap on that pedal.  It creates the illusion that the TB pedal is the offender, because the popping only happens when the TB pedal is switched, but not when the e-switched pedal is bypassed or engaged.

The cure: IF you routinely plug your Dynacomp into something like a Boss or similar pedal, then solder a 1M resistor from the tip to ground on the input jack of the e-switched pedal, allowing the input cap on that pedal to drain.

Atodovax

Thank you all for replying. im using the pedal alone and i tried with pulldown ressitors. I think the circuit itself has gone microphonic somehow... Anyone experiencing the same? The layout is this http://effectslayouts.blogspot.com/2015/04/mxr-dynacomp.html

Mark Hammer

So does the amp you plug into have an input cap with a "free end"?

Atodovax

So does the amp you plug into have an input cap with a "free end"?
Hello Mark, i really dont know. Its a Soldano Slo clone and i dont feel safe openng it ha ha. But none of the other pedals i have built behave this way. I mean its not something terrible... Its just there but as one other guy mentioned in some other post, i could live with it if its something to expect from an MXR Dynacomp. If its something wrong that i am doing then i dont want it anymore. Its really frustrating. Its a fainted click but when playing at loud volume, if a strung a chord and quickly press the 3pdt, i hear a strong "POP" or "click" acompanied with the increased volume (with the pedal set high enough) But if i do the same with a Fuzzface, Overdrive, Distortion, i dont hear any POP or click, just the obvious jump of volume

Atodovax

Its not so much pronounced when the guitar is muted. But if i crank the amp loud enough and put the pedal with both knobs at full i can also hear the "CLICK" or "POP" much louder than in other pedals

Atodovax

Show us the layout and the schematic, that you are actually using, and we can help you.
http://effectslayouts.blogspot.com/2015/04/mxr-dynacomp.html
This is the layout.