[Debugging] Rat Clone

[thedefog]

Is it intermittent, or is it all the time like that?

[elenore19]

Is it intermittent, or is it all the time like that?

All the time.

[thedefog]

And you say you're having this same issue with two other pedals? Are they all DIY pedals, or commercial ones as well? Are you running a daisy chain for power, or batteries, or separate wall-warts?

[elenore19]

And you say you're having this same issue with two other pedals? Are they all DIY pedals, or commercial ones as well? Are you running a daisy chain for power, or batteries, or separate wall-warts?

Yeah, 2 other pedals. Both DIY. One of which I found out it's a common thing to happen. So basically just 1 other pedal with the same issue.
I'm running a daisy chain for power. When I power them up for testing I only plug in the one that I'm testing. Not sure if it matters how many I'm powering or not...But yeah.

The rat is the only pedal with a battery clip, which I have yet to test out. But would that really be the problem? The daisy chain power works on all my other pedals just fine and seems to work fine on these ones too...just the signal loss.

Thanks for the help, I really hope I can get this figured out.

[ashcat_lt]

Have you measured the IC voltages since you switched out that pot?  You must have about half the battery at pins 2, 3, and 6 for it to work properly.  You were pointed toward the voltage divider that creates that bias voltage, but never told us how that measured.  From that 10K/10k junction there's a 1M resistor which carries the bias to the input at pin 3.  Measure voltage on either end of that 1M.

[elenore19]

Have you measured the IC voltages since you switched out that pot?  You must have about half the battery at pins 2, 3, and 6 for it to work properly.  You were pointed toward the voltage divider that creates that bias voltage, but never told us how that measured.  From that 10K/10k junction there's a 1M resistor which carries the bias to the input at pin 3.  Measure voltage on either end of that 1M.

Measured the voltage at the 1M and it was 4.13V.
I also measured the voltage at pins 2, 3, and 6. They were..
Pin 2: 4.57V
pin 3: 4.10V
pin 6: 4.57V

Is p3 too low?
Thanks for all the help.

[thedefog]

I'd test it out with a battery, that'll eliminate any potential power supply issues. If it still gives you trouble, make sure all of your ground points are connected and that no wires running to the PCB have become frayed during your poking around.

If that all checks out, then triple check for solder bridges on the board, it looks like you used a lot more solder than you needed. You also have your wires mounted directly on the bottom of the board, which I wouldn't recommend since it makes it easier for frayed strands to touch places it shouldn't on the PCB. It's cleaner to go through the top like the rest of the components.

If all of that checks out, maybe try swapping out that 2n5458 for another one if you have an extra. Good luck!

[thedefog]

!

[elenore19]

I'd test it out with a battery, that'll eliminate any potential power supply issues. If it still gives you trouble, make sure all of your ground points are connected and that no wires running to the PCB have become frayed during your poking around.

If that all checks out, then triple check for solder bridges on the board, it looks like you used a lot more solder than you needed. You also have your wires mounted directly on the bottom of the board, which I wouldn't recommend since it makes it easier for frayed strands to touch places it shouldn't on the PCB. It's cleaner to go through the top like the rest of the components.

If all of that checks out, maybe try swapping out that 2n5458 for another one if you have an extra. Good luck!

Thanks for the input. I'll try that out. Yeah, I was using too big of solder when I did this board, so there's definitely excess. Maybe I'll go to town with some solder braid and soak up a ton of it. Then check for solder bridges etc....I'm pretty sure I have a bunch of 2n5458's lying around so hopefully I can make the replacement if I need to.

Thanks again for the input.

[elenore19]

Resoldered a bunch of spots. Removed a ton of excess solder and searched for solder bridges a good 3 times. Still nothing.
I'm going to search one last time for solder bridges with a higher powered magnifying glass and hopefully fix this guy.

Thanks again for all the help from everyone. I greatly appreciate it.

-Elliot

[thedefog]

Resoldered a bunch of spots. Removed a ton of excess solder and searched for solder bridges a good 3 times. Still nothing.
I'm going to search one last time for solder bridges with a higher powered magnifying glass and hopefully fix this guy.

Thanks again for all the help from everyone. I greatly appreciate it.

-Elliot

Recheck your resistor values too.

[elenore19]

Recheck your resistor values too.

Alright, on it. Thanks.