Fixed! PedalPCB Revision Overdrive TWA Source Code Clone switch pop only when turning on?

[tolstokes]

Build Rating

5.00 star(s)

 

[tolstokes]

Nice overdrive! I may still experiment with different chips. Huge pop only when turning on. No pop when turning off. Any ideas? Thanks!

 

[SpringReverbFan1234]

Looks like your GND and SW wires are swapped on the footswitch. Not sure if it would cause that issue but that could be it.

 

[tolstokes]

You spotted it! Thank you!

 

[tolstokes]

Now that I have the wires corrected, I find I really like the 4558d as the clipping ic. I like LF353p for the other chip. It is a bit noisier than my cjod clone. I am wondering if it's due to the input circuit. The transistors with the bite control are sort of a pregain no? Darlington pair amplifying by a huge amount?

 

[owlexifry]

It is a bit noisier than my cjod clone

assuming CJOD is a mere TS808 clone - IME this source code overdrive appears to generate a little more gain, but definitely had a lot more volume output in my breadboard build.

wondering if it's due to the input circuit. The transistors with the bite control are sort of a pregain no? Darlington pair amplifying by a huge amount?

could be wrong, but i'm assuming this is just a fancy input buffer


note:
there's also this 'additional' gain stage before the clipping stage:

i assume this would be responsible for the additional gain & noise.

^ also has this same gain stage on the output following the volume control (vs. a unity buffer on TS808)

 

[tolstokes]

Thanks for the insights! It's an odd design considering how many electrolytics and tantalums are in the signal path. I thought that was avoided nowadays because they can introduce noise. I also used the tc1044spca charge pump. I thought I had read somewhere that it was an improvement over the max1044?

 

[tolstokes]

Yeah the cjod is a ts808 clone with a few changes. I built mine using a hoarde howler PCB from effectslayouts. Funny thing with that one, when I run it at 12 volts, it sounds fantastic! Less hiss, more headroom, etc etc