Carmine suddenly very loud

[Bret608]

I boxed this last week and tested it out; sounded great (see build report over in that area of the forum). Tonight is the second time I played it and for some reason it's extremely loud, at least intermittently. With the volume and gain all the way down, there is still sound, like a clean-ish boost. Turn the gain up and its pretty bruising! I also noticed some ground-y sounds when turning the pots. I'm suspecting a dodgy joint on one of the diodes. Any other trees to bark up would be most welcome!

 

[jwin615]

Clippers would be my guess as well.
If you used a Elcap for C5, it could be leaking DC on the tone and output pot. That would potentially add dc offset to the clippers as well

 

[Bret608]

Yep, that one is an electro. Is there anywhere I could look for stray voltage that shouldn't be there? Otherwise, time for a reflow party, I guess!

 

[jwin615]

Leg 1 of the tone pot
Can swap C5 for a film if you see DC on the tone pot. Doesn't have to be 1u, if you're low on stock.

 

[Bret608]

Thank you, I will check that out. I don't think I have a film cap in the ballpark at the moment but would drop one in my next order or grab one at work. A couple of other things to note, which I'm now remembering from when I tested the board outside of the box (and which, at the time, I chalked up to my testing box getting dodgy): 1) I wasn't getting sound at first; it was like things had to charge up or something; 2) I was getting crackle and even some pops/ground-type noise when I moved the pots?

 

[jwin615]

DC on the pots would cause crackle and DC on the output would cause hum

 

[Bret608]

Okay, so I check leg 1 on the tone pot with my DMM. I'm getting 0 up to 0.7mv at most. Let me know if that sheds any light. It does seem like an electro in the signal path may have been a less than optimal choice if film was an option, unless I'm missing something.

 

[falco_femoralis]

post pics

 

[Bret608]

Let's start with this and I'll get the bottom of the board if we get to that point (since I'd have to yank it from the box, lol...):

 

[Chuck D. Bones]

Visual inspection???

 

[Bret608]

The picture may not be a huge value-add, true; I've already checked resistor values, orientation of anything with polarity, that the diodes still have the same fv they did before soldering, etc. Thank you to anyone willing to take a look, though!