Angry Charles - strange thumping noise

[ckendall924]

I finished the Angry Charles build and fired it up. It works! Only thing is that I'm getting a strange thumping noise when the gain and volume is turned up. No noise when those pots are turned down all the way.

I was running my guitar straight into the pedal and from there into my Fender solid state 1X8 combo. Powering the pedal with a TrueTone 1spot power adapter.

No idea what to look for... any suggestions?

 

[eh là bas ma]

hello, welcome !

First thing that comes to mind is insulating the pots so their back aren't shorting the pcb. A simple piece of cardboard or plastic between the EQ controls and the pcb should prevent that.

 

[ckendall924]

I had thought about doing that, but didn't. Man, that would be great if that's all it is! I'll give it a go and report back. Thanks!

 

[ckendall924]

Fixed!

I reopened the pedal and slid a piece of cardboard in behind the EQ pots and the PCB. Re-tried the pedal as before with the 1spot and pedal direct to the amp. Still the light tapping/thumping noise.

I had read on a different forum about a similar issue and the suggestion was made to put another pedal in the signal chain between the Angry Charles and the amp. (Citing an impedance issue).

I added the pedal to my pedal board with a number of other pedals in the signal chain after it. THAT DID THE TRICK!

This pedal sounds absolutely dynamite! Love it already, can't wait to mess around with more!

 

[Feral Feline]

I would still want to know what the heck is going on with the circuit. Adding other pedals is a band-aid solution and works great until you take the band-aid off. I'm guessing it's an inherent impedance mismatch, and suspect it's the outgoing (hence the pedals between amp "fixing" the problem). I'm still learning about how to set the input and output impedance, but you want high-impedance on the input, and low impedance on the output.

I'd want to measure/figure out the output impedance and maybe try to lower it. Also, I'd check the amp and make sure it's input-impedance is correctly set.

Then again, it might not be an impedance issue at all, but something else entirely...