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DIY Stompboxes => Building your own stompbox => Topic started by: Atodovax on June 05, 2020, 04:42:21 PM

Title: Is there any pcb layout for a Mxr Dynacomp with no switching POP noise?
Post by: Atodovax on June 05, 2020, 04:42:21 PM
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
Title: Re: Is there any pcb layout for a Mxr Dynacomp with no switching POP noise?
Post by: roseblood11 on June 05, 2020, 06:02:48 PM
It's not the layout, that causes the problem... ;-)

Title: Re: Is there any pcb layout for a Mxr Dynacomp with no switching POP noise?
Post by: Atodovax on June 07, 2020, 08:35:22 PM
Quote from: roseblood11 on June 05, 2020, 06:02:48 PM
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?
Title: Re: Is there any pcb layout for a Mxr Dynacomp with no switching POP noise?
Post by: bluebunny on June 08, 2020, 05:12:27 AM
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.
Title: Re: Is there any pcb layout for a Mxr Dynacomp with no switching POP noise?
Post by: roseblood11 on June 08, 2020, 07:50:22 AM
Show us the layout and the schematic, that you are actually using, and we can help you.

Title: Re: Is there any pcb layout for a Mxr Dynacomp with no switching POP noise?
Post by: Mark Hammer on June 08, 2020, 08:02:37 AM
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.
Title: Re: Is there any pcb layout for a Mxr Dynacomp with no switching POP noise?
Post by: Atodovax on June 08, 2020, 11:15:32 AM
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
Title: Re: Is there any pcb layout for a Mxr Dynacomp with no switching POP noise?
Post by: Mark Hammer on June 08, 2020, 06:33:02 PM
So does the amp you plug into have an input cap with a "free end"?
Title: Re: Is there any pcb layout for a Mxr Dynacomp with no switching POP noise?
Post by: Atodovax on June 08, 2020, 07:38:39 PM
Quote from: Mark Hammer on June 08, 2020, 06:33:02 PM
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
Title: Re: Is there any pcb layout for a Mxr Dynacomp with no switching POP noise?
Post by: Atodovax on June 08, 2020, 07:41:24 PM
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
Title: Re: Is there any pcb layout for a Mxr Dynacomp with no switching POP noise?
Post by: Atodovax on June 08, 2020, 07:43:08 PM
Quote from: roseblood11 on June 08, 2020, 07:50:22 AM
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.