Previously Fine, Now Making Noise

[joelorigo]

Suddenly the Tube Screamer part of my Kentauraide / Tim combo pedal is making a hissy sound. It was previously quiet. Any usual culprits to this kind that of thing??

Here's a demonstration:

The Build Report:

Tres Hombres (Custom 2 in 1)

Here is my first 2 in 1build. It is 2 Effects Layouts projects, the Mitt (a Tim) and a Kentaride (a TS10 and a Klon in one PCB). I call it the "Tres Hombres." It turns 3 spaces on my pedalboard into 2, so that's nice. It started out fun with the Mitt built first and working right away, but...

forum.pedalpcb.com

 

[chris.knudson]

Not particularly familiar with this pedal. What voltage are you running it at -- are there any charge pumps in this circuit? Have you tried pulling it out of the signal chain to test it by itself?

 

[joelorigo]

Not particularly familiar with this pedal.

Here is the circuit:

KENTAURIDE – Effects Layouts

What voltage are you running it at

9V from a Pedal Power 3 +

- are there any charge pumps in this circuit?

Yes, a 7660

Have you tried pulling it out of the signal chain to test it by itself?

I haven’t, I will.

 

[music6000]

Have you tried pulling it out of the signal chain to test it by itself?

 

[joelorigo]

Have you tried pulling it out of the signal chain to test it by itself?

I'm getting inconsistent results here. I pulled it off the board and tired it in isolation with another power supply and there was no noise. then I put it back in the same place in my board and there was noise. Then I took it off and tried it again in isolation and not noise. Then I put it pack on the board and no noise. Then I turned it off and turned on and off the other 2 circuits in the pedal and came back to the TS and there was noise. Then I turned it off and back on and the noise was louder. Then I gave it a firm tap and it was gone. Then I turned it off and on a few times and turned the other 2 circuits off and on and came back to the TS and no noise. I turned it off and on a couple more times and no noise.

So based on that it seems like some mechanical / connection thing??

I remembered I did have this board stored upright for a few days. When noticing this noise it was the first time I had tried that circuit since.

 

[chris.knudson]

I'm getting inconsistent results here. I pulled it off the board and tired it in isolation with another power supply and there was no noise. then I put it back in the same place in my board and there was noise. Then I took it off and tried it again in isolation and not noise. Then I put it pack on the board and no noise. Then I turned it off and turned on and off the other 2 circuits in the pedal and came back to the TS and there was noise. Then I turned it off and back on and the noise was louder. Then I gave it a firm tap and it was gone. Then I turned it off and on a few times and turned the other 2 circuits off and on and came back to the TS and no noise. I turned it off and on a couple more times and no noise.

So based on that it seems like some mechanical / connection thing??

I've seen this problem in other troubleshooting threads. That's why I suggested pulling it out and testing on it's own. I think the issue could be with your charge pump.

I don't know that much about this, but take a look at this thread -- might give you some ideas...

Charge Pump Noise - Pedal Order Dependent

I need the collective brain power of this fine forum please to help me solve this... I have two PedalPCB pedals - a Kliche Mini (Klon), and a Cetus (Victory Kraken). I'd like to think I build quality pedals, with clean soldering, and clean, minimal wiring. Both pedals use a charge pump to...

forum.pedalpcb.com

 

[joelorigo]

Hmm, that's interesting.

I had an issue where I was getting a high pitched whine when I used my TC Electronics Quintessence after my Aion Klon clone which had a TC1044SCPA. Apparently some digital pedals don't like being after a TC1044SCPA. I was advised on this forum to try a 7660SCPAZ which fixed the issue. Then I replicated the whine with the other pedals I had with a TC1044SCPA, and using the 7660SCPAZ fixed that. I could try the LT1054 I guess.

However, what about the fact that it was fine for a year and suddenly started? And the fact that I gave it a "love tap" and it stopped? Would any off that be related to a choice of what charge pump to use?

 

[chris.knudson]

Then I gave it a firm tap and it was gone.

This does seem to suggest something mechanical -- perhaps a bad ground, or potentially a ground loop. When I get problems like the, I usually open it up and run a signal through the pedal, and then I tap around on the wires and connections to see if any of them produce noise or crackle. Could be as simple as a lose connection or cold solder joint.

 

[jwin615]

That's an interesting implimentation of the 7660. It's the datasheet circuit for
COMBINED NEGATIVE VOLTAGE CONVERTER
AND POSITIVE DOUBLER fig 20

But the negative rail is disconnected.


Anyhow, the 7660 switched at 10k. Not good. Check your cap orientation around it. Try a different one if you have one.
Make sure you didn't sub/mixup any diodes for D6,7,8

 

[jwin615]

Just saw that it was working fine for a year. I'd try and swap the charge pump. It may be heterodyning.
May be the ESD boogie man coming out to play.