madbeanpedals::forum

Projects => General Questions => Topic started by: Barry Jive on December 06, 2022, 07:16:56 PM

Title: Kompromat Compressor - scratchy clip knob
Post by: Barry Jive on December 06, 2022, 07:16:56 PM
I completed this Kompromat build recently. I've played it for a couple of shows and really like it, I just have a question about the clip knob. It makes a significant scratchy sound when I turn it, and when at minimum, the pedal is more noisy. I attached a gut shot and posted a video with sound here:
https://imgur.com/a/mwwnxRA
There is a guitar (with the volume turned all the way down) plugged into the input. I've tried a couple of different power supplies, same thing. I have followed the instructions with regards to biasing.
If I were keeping the pedal, I wouldn't even worry about it, but it's a commission. Is this normal for this circuit?

Thanks!
Title: Re: Kompromat Compressor - scratchy clip knob
Post by: brobri on March 26, 2023, 01:00:10 AM
I think this might be a "scratch ok" control. To my untrained eye, it looks like it's interacting with the bias control, as a headroom control, which implies a change in voltage. I finished my build last night and have the same result, but it doesn't bother me. I can only imagine having to dial that in when the pedal changes chains or instruments, give it a tweak, make sure it's happy, and forget about it. If it's really a problem, pick some low and high values in the pot range (25/75%) and turn it into a switch, as I've seen mention of regarding other designs. Or, set it up for the most headroom with a fixed resistor, and then fill in the hole!

-bb