Nobleman bass mod

Or maybe you need a different pedal. ;)
Narrowed down the problem to the 2.2 uf cap in C5.
I reflowed the solder and it improved slightly...
I can lightly push on the cap and oscillation stops for a minute... I'll play a little bit and then it slowly starts back as a "womp womp womp" sound... like a helicopter rotor just starting to fire up.

I can press it again and it repeats. I'm just going to desolder and try another cap
 
The Audition board might be a contributing factor. If the pot bodies are not grounded, that could cause oscillation too. Only way to be sure is to box it up. I've had varying luck on a breadboard.
And I never honestly thought about the audition board, to be honest... very well could just be that.

Only reason I went straight to troubleshooting mode was after searching the forums and finding another gentleman who had the same issue with the very same pedal. Regardless, I swapped out the cap that seemed to be causing the issue and am ready to test. The swap to the 500k pot really did help this build though. Gave it a much more usable *to me* range of gain, as 7oclock to noon wasn't really much of a change (to my half-shot ears) with the really good and usable overdrive only coming in around 1-5 o'clock. Felt like the pedal had so much more to give when the 250k "ran out of gas"...

For reference, my favorite guitar is a Mayer Stratocaster, and the pickups in it aren't terribly hot, even for a strat, and my main amp is a 69 Bandmaster Reverb with EV-12m speakers... so I'm always needing a bit MORE in my pedals to get things where I want em... but thus combo sounds so awesome together that I never want to use anything else.
 
The Audition board might be a contributing factor. If the pot bodies are not grounded, that could cause oscillation too. Only way to be sure is to box it up. I've had varying luck on a breadboard.
Another stupid question I just now thought of... I once built a katana clone and the LED went bad... the Pedal developed a weird hum to it... swapped the bad flickering led and it was fine afterwards...

I haven't installed an led on this board yet (I save that for when I install it in the case for proper fitment... Could this also cause such an issue?
 
An LED is not going to make hum. But a bad ground could make an LED flicker and it might also cause hum.

When we open a pedal, work on it and put it back together, it is very likely that we will disturb more parts of the circuit than we intended. We might fix something without realizing it, or discover stuff, fix it and then not remember everything we touched with a soldering iron.

FYI, setting an A500K pot to 2:00 is the same as setting an A250K pot to 5:00. In other words, all the extra gain in that A500K pot happens between 2:00 and 5:00.
 
"That might be the right move for someone who likes their sweet spot to be near noon and never deviates much in either direction. I know a guy on these forums who does just that."

Wow - I wonder who that could be?
 
I think Chuck thinks I'm like that. In reality I often set controls in wildly unpredictable places. Sometimes I'll use treble at 11.00 or 1.00, or bass at 1.30. I just don't care. I'm crazy. Just today I played for over ten minutes with bass at 3.00! Sure, I put it back to noon afterwards but still - ten minutes!!

But really, when I work on a circuit for a pedal I am likely to use a lot I do try to get it sounding how I like with tone controls around noon. Then I have room to move either way. Gain and volume it's not such an issue. I have one pedal where I rarely raise gain above 9.00, and Chuck complains about that! You can't win. Sure, he knows more than I ever will, is generous with his knowledge and has helped me enormously to get sounds I like but he's so picky!
 
I think Chuck thinks I'm like that. In reality I often set controls in wildly unpredictable places. Sometimes I'll use treble at 11.00 or 1.00, or bass at 1.30. I just don't care. I'm crazy. Just today I played for over ten minutes with bass at 3.00! Sure, I put it back to noon afterwards but still - ten minutes!!

But really, when I work on a circuit for a pedal I am likely to use a lot I do try to get it sounding how I like with tone controls around noon. Then I have room to move either way. Gain and volume it's not such an issue. I have one pedal where I rarely raise gain above 9.00, and Chuck complains about that! You can't win. Sure, he knows more than I ever will, is generous with his knowledge and has helped me enormously to get sounds I like but he's so picky!
Same here... I don't like maxing out controls or cutting them all together... I like having the "usable tones" in the center so I can go either way... because I feel like if I'm maxed out, there might be even more I like just beyond the horizon
 
It's easy enough to find out, then adjust resistance and/or taper as req'd. What I can't abide is a knob that makes a HUGE jump between 7:00 and 8:00 or between 4:00 and 5:00.
 
I saw another forum member have the same issue (also noted when the gain was turned up).
It doesn't really manifest in normal playing... but if you lightly touch a string you can hear it. I didn't make any other adjustments or modifications so its strange this would occur. You mentioned before that the 4558d op amp can only handle so much gain /bandwidth. Could this be the issue manifesting itself? or perhaps a different capacitor/resistor is needed in the gain section to compensate for the increased pot value.

Any suggestions for an op-amp that would
Just curious Chuck You mentioned the 4558d running out of bandwidth at higher gain. Do you have a suggestion for an alternate OpAmp I could drop in to remedy that issue?
Sorry I'm re-booting an old thread... We've had two family members dealing with Cancer/Leukemia the past few months, so pedals have had to take a backseat... For now things are a bit better and I'm able to get back into other things.
 
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