SOLVED Cataclysm Delay w/ 2Khz noise

[PunchySunshine]

New pedal builder here. Finishing up my fourth pedal, I've finally hit a problem and my luck has run out. I made the Cataclysm Delay and everything functions properly except there is a steady 2Khz noise happening. It's only when the pedal is on. It doesn't matter if it's inside or outside the box. I've tried powering with a 9v battery and it's still there. I've swapped out the tl072 opamp. The PT chip is getting 5.2 volts on the first pin and 2.6 volts on the second pin. I've run out of ideas on my own and I'm hoping you wonderful ppl can take a look at these pics and we'll get it sorted out.
Thank you in advance!

 

[Boba7]

Do you have other PT2399 you could try?
Is the noise present when the blend pot is turned down (delay signal off)?

 

[PunchySunshine]

Do you have other PT2399 you could try?
Is the noise present when the blend pot is turned down (delay signal off)?

Thank you for helping Boba7!
I just ordered another PT2399 this morning so....a couple weeks on that.
The noise is there with the blend pot turned down.

 

[Boba7]

Do you buy them from Tayda? I’ve had a LOT of bad 2399 from them over the years.

 

[PunchySunshine]

Do you buy them from Tayda? I’ve had a LOT of bad 2399 from them over the years.

I did get them from Tayda. I'll try another source! Thanks.

 

[Boba7]

I did get them from Tayda. I'll try another source! Thanks.

You welcome! If the problem persiste Im sure people smarter than me will come to the rescue!
If you remove the pt2399 and bring the mix to zero, I imagine there’s no more noise right?

 

[PunchySunshine]

You welcome! If the problem persiste Im sure people smarter than me will come to the rescue!
If you remove the pt2399 and bring the mix to zero, I imagine there’s no more noise right?

PT2399 removed, mix to zero and noise is still there.

 

[Boba7]

PT2399 removed, mix to zero and noise is still there.

Not the chip then...
That's odd. I imagine you've already checked all your resistor and cap values?

 

[PunchySunshine]

Not the chip then...
That's odd. I imagine you've already checked all your resistor and cap values?

Time to check them again I guess. I'm about ready to nuke the board and try over with proper caps.

 

[fig]

The resistors check out...

 

[PJS]

I think I would run an audio probe through and see whereabouts the noise starts, and whether it is being generated all through the circuit or in one place. If it starts in a defined place then try replacing the component just before, and if that doesn't work then the components just around that spot. My experience with bad components is usually noise or low frequency hum, not higher frequencies, but you never know.

 

[Sturdag Lagernathy]

Just curious, but how did you find it's a 2 kHz frequency?

 

[Boba7]

I think I would run an audio probe through and see whereabouts the noise starts, and whether it is being generated all through the circuit or in one place. If it starts in a defined place then try replacing the component just before, and if that doesn't work then the components just around that spot. My experience with bad components is usually noise or low frequency hum, not higher frequencies, but you never know.

Agree, I find a high pitched sound like that quite surprising, especially since he also tried it with a battery

 

[music6000]

Time to check them again I guess. I'm about ready to nuke the board and try over with proper caps.

Have you tried changing the TL072 for something else??????
ie 4558

 

[Boba7]

Have you tried changing the TL072 for something else??????

Yep, he said he did.

 

[Scruffie]

Agree, I find a high pitched sound like that quite surprising, especially since he also tried it with a battery

Filters with the Q factor set too high will oscillate at the set frequency, so a wrong value could cause that symptom.

 

[PunchySunshine]

Just curious, but how did you find it's a 2 kHz frequency?

I used a freq analyzer app on my ipad. It was just over at 2.05 or 2.06 Khz but I assumed rounding on that number didn't hurt.

 

[PunchySunshine]

I think I would run an audio probe through and see whereabouts the noise starts, and whether it is being generated all through the circuit or in one place. If it starts in a defined place then try replacing the component just before, and if that doesn't work then the components just around that spot. My experience with bad components is usually noise or low frequency hum, not higher frequencies, but you never know.

This is definitely the next course of action. About a week ago I ordered the 100nf cap so I can make my probe. I appreciate the advice!

 

[spi]

I had an issue like this with an overdrive once. Turned out it was a bad electrolytic cap. I discovered the bad cap simply by touching them all, and hearing the tone change on the bad one. Try touching the caps or the solder traces and you might luck out and find it without the probe.

 

[music6000]

I had an issue like this with an overdrive once. Turned out it was a bad electrolytic cap. I discovered the bad cap simply by touching them all, and hearing the tone change on the bad one. Try touching the caps or the solder traces and you might luck out and find it without the probe.

I was looking at the brand name on those Electrolytics, I'm not familiar with it???
My gut feeling is one of those also, everything else on the board looks fine!