MXR Commande Phaser M-161 switch pop

[beedoola]

This pedal has a pop/thud when the pedal is engaged/bypassed. It uses a DPDT latching switch. Its not a stomp switch but a small plastic switch triggered by the large plastic piece as shown in the picture. Here is a schematic. Any advice on what to check for to debug the pop?

[antonis]

I'd start with lowering R4 value , till pop is eliminated..
In case of R4 needed is lower than 100k say, thus severely dominating input impedance, I'd proceed to alter indicator LED configuration..

P.S.
I'm pretty sure for the later 'cause 100nF input cap doesn't seem to me potent for popping issues, but you never know..

[Mark Hammer]

Same pop/thud with battery and external power?

[beedoola]

Good questions. It still did it using a power supply. I resoldered the footswitch pins and also shot some Deoxit into the switch a few times and exercised it. It was definitely the switch as sometimes the LED would be dimmed when bypassed and fiddling with the switch would remedy it. After a few more sprays of Deoxit and clicking the switch on and off - without power to the circuit - it seems to have solved the issue.

[Mark Hammer]

Congrats!  I have one of the Commande series flangers.  The PCB-mount DPDT switches they used for bypass were not exactly the hardiest and most robust, so it is not surprising that the problem lay within the switch.  They are very cheap and abundant, so consider buying a few to have around, when replacement seems like a more viable solution than cleaning.  Should you wish to sell the pedal, I can't imagine that switch replacement will be considered to devalue the pedal.

It's a pity there are not 3PDT PCB-mount push-button switches.

[bartimaeus]

instead of adjusting R4, i'd first suggest checking the caps to make sure they've kept their value and aren't super leaky. presumably the pedal didn't pop back when it was first manufactured? i'd check C2 and in particular C10. maybe also C11 and C12.

my bad, just saw it was a dirty switch haha

[Ell]

Congrats!  I have one of the Commande series flangers.  The PCB-mount DPDT switches they used for bypass were not exactly the hardiest and most robust, so it is not surprising that the problem lay within the switch.  They are very cheap and abundant, so consider buying a few to have around, when replacement seems like a more viable solution than cleaning.  Should you wish to sell the pedal, I can't imagine that switch replacement will be considered to devalue the pedal.

It's a pity there are not 3PDT PCB-mount push-button switches.

I recently read a thread of yours on a video comparing the Boss BF-2 and the HF-2. What are your thoughts on MXR Flangers?