SOLVED Pedal signal passing through with volume at 0 (pot was defective and had a "catch" in it... cycling the knob multiple times =dead. Replaced, fixed!

[ChrsGuit]

So, I recently completed three identical Boteh drive builds... one for me, two for friends...
Two sound relatively identical... One is considerably louder than the other two... To narrow down the issue, I'll also add that the louder of the three also passes signal when the volume on the pedal is at "0", which I can assume is possibly my issue... like the potentiometer is not applying the resistance that it should to properly regulate the output. I confirmed both volume pots are the correct B100k, and all solder joints appear to be intact. What would be my first step in locating the issue? The leg on R18 (511k resistor) looks a little suspicious to me at a glance, like it might not quite be seated like the rest are... so that was going to be my first target...
Enclosed are a shot of the internals and the schematic. (also note, the Q2 is the "wrong" component. I made this mistake on my first build, but shooting it out against the name-brand counterpart, I preferred the sound, so I repeated it on the subsequent builds.)

 

[jimilee]

Check all your values and reflow all your joints regardless of how they look, that’s usually your starting place. I would measure the volume pot with your DMM to see if it’s working internally.

 

[ChrsGuit]

Check all your values and reflow all your joints regardless of how they look, that’s usually your starting place. I would measure the volume pot with your DMM to see if it’s working internally.

Problem solved... Volume pot was defective... I cranked the volume to check the sweep and my knob stopped way short... Rolled it back to (what I thought was) zero and gave a little pressure... the pot "gave" and went on down... like the pot had a really bad "catch" in it... I cycled it a few more times and the pedal signal died altogether...
Replaced the pot, and it's fine...
Defective pot... my first time finding one of those!

 

[jimilee]

Problem solved... Volume pot was defective... I cranked the volume to check the sweep and my knob stopped way short... Rolled it back to (what I thought was) zero and gave a little pressure... the pot "gave" and went on down... like the pot had a really bad "catch" in it... I cycled it a few more times and the pedal signal died altogether...
Replaced the pot, and it's fine...
Defective pot... my first time finding one of those!

I think I may have only run into this once. I have had a few crumble in my hands. They were all Tayda branded pots.

 

[ChrsGuit]

I think I may have only run into this once. I have had a few crumble in my hands. They were all Tayda branded pots.

I order mine from Stompbox parts, and never usually have any problems... a couple will have a slight catch from time to time, but not like this one did... It was so bad, I incorrectly installed the knob, believing it to be at "0"

 

[jimilee]

I order mine from Stompbox parts, and never usually have any problems... a couple will have a slight catch from time to time, but not like this one did... It was so bad, I incorrectly installed the knob, believing it to be at "0"

That’s where I’ll be getting mine as well.

 

[ChrsGuit]

That’s where I’ll be getting mine as well.

Seems that solved the problem... All three seem to be extremely close in sound... so close that it'd be hard to tell them apart in a blind test... Pot tolerance must be really close as well because you can put all knobs and switches on the same settings and hear no differences! Very pleased with the results...