[sdiy] [OT] faulty distortion pedal

[Michael Zacherl]

Hi, just had soundcheck for the gig tonight.
The viola player used a small (probably cheap-ish) distortion pedal, 
which ran off a wall-wart. [1]
There was an audible pulse, a dull click, in the signal from the pedal. 
Much like from a metronome. 
In fact, before seeing the thing we all told her to switch it off. ;\
I could see the indicator in the knob going darker with the pulse which 
led me to the thought it might be the PSU.
The sound was what one not knowing the pedal would expect but she claimed it sounded wrong.
I think I came across that phenomenon ages ago but alas I can’t remember what it was.
I can’t say for sure, but I think the PSU was a switched type. 
I didn’t touch it but it looked rather small.
I ‘just curious’ what could cause this.
Any thoughts?
Thanks - Michael.


[1] much like these http://www.thomann.de/gb/movall.html


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