Kliche Mini oscillation

[flippy69]

Hello, this is my first time doing a pedal pcb version of this pedal. I have built a few Klone’s before. I also know that this design oscillates when knobs are all the way up however, in this case the oscillation starts the minute clicked on and continues AFTER it is switched off. You can slow it down by turning knobs down but it never goes away. I took the entire pedal out of enclosure, re flowed some questionable joints and out back together. I also switched out the 1044 with no change. Please help.

 

[Danbieranowski]

Where did you get your 1044 from?

 

[music6000]

Did you use a Dust cover on the Tone pot?
What type of Input & Output jacks.
More photo's required of Jack connections & Solder side of PCB.

 

[flippy69]

Where did you get your 1044 from?

I think I might have gotten them from eBay. Is there a way to determine if I got counterfeit chips?

 

[Dan0h]

Did you pull the Ge diodes before taking this photo? Because they are not in.

 

[Danbieranowski]

I think I might have gotten them from eBay. Is there a way to determine if I got counterfeit chips?

Not that I know of, but there were other 1044 builds that had oscillation issues in the past that seemed related to the chip and we settled on Tayda being a known good source for a chip that didn’t have that issue. Hope you get it sorted!

 

[Nostradoomus]

Is it a constant 10khz tone? If so yeah that’s the charge pump.

 

[spi]

Does your 1044 chip have an S in the suffix?

 

[music6000]

Did you use a Dust cover on the Tone pot?
What type of Input & Output jacks.
More photo's required of Jack connections & Solder side of PCB.

You need to supply Answers & Pictures to sort your issue out.
Can you get hold of a 7660SCPAZ, that is what I use in all my Builds!
That is what the Klon uses!

 

[Chuck D. Bones]

I think I might have gotten them from eBay. Is there a way to determine if I got counterfeit chips?

Post a hi-res pic of the 1044, showing all of the printing. The counterfeiters usually get the logo or LDC wrong. That's one way of telling. Best way to avoid counterfeit parts is to NOT buy them on eBay.

You said "this design oscillates when knobs are all the way up" but that's not entirely true. I have one made in China and one I built and neither one oscillates. This thing is not particularly high-gain, so oscillation should not be happening. Poor grounding and/or lead routing can cause oscillation. Try sanding or scraping the paint off of the inside of the box where the pots, switch and jacks mount. Everything should be grounded to the case and that thick coat of powder coat on the inside prevents electrical contact.

And like the other guys said, a bad charge pump will inject excessive switching noise onto the power supply rails, which then gets coupled everywhere.

Not sure why the charge pump circuit uses 1uF caps. 10uF is standard.

 

[flippy69]

Here is a pic. Thank you for the tip. I just ordered the same part from digikey. Hopefully that will do the trick.

 

[flippy69]

Did you pull the Ge diodes before taking this photo? Because they are not in.

Yes the diodes make no difference with this issue until I fix this issue, Diodes aren’t necessary.

 

[flippy69]

Does your 1044 chip have an S in the suffix?

Yes it does.

 

[flippy69]

Does your 1044 chip have an S in the suffix?

You need to supply Answers & Pictures to sort your issue out.
Can you get hold of a 7660SCPAZ, that is what I use in all my Builds!
That is what the Klon uses!

I will be getting my hands on some. Thank you

 

[music6000]

I will be getting my hands on some. Thank you

Can you use the Resistor Calculator & confirm your Resistor values.
I know for sure there are some different resistor values (68k) than listed in the BOM.
Those 100K dont look right?

Just click on Bands for 5 colours

Resistor Calculator

Resistor Calculator is an App developed by CherryJourney to help the user find the value of a resistor.

resistor.cherryjourney.pt

 

[Chuck D. Bones]

Here are pix of two TC1044S charge pumps.
The one on the left was purchased from Small Bear in Sept 2019. My confidence level is 90% that this part is legit. Small Bear is not a factory authorized distributor, but has a history of selling legit parts.
The one on the right was purchased from Mouser in July 2019. My confidence level is 99% that this part is legit. Mouser is a factory authorized distributor.

Note that the font, Microchip logo and positioning on the face of the part is consistent. The differences in the package molding is of minor concern. The same factory will have a large number of package molding machines and they may not all be identical. The finish and color of the packages are consistent.

Now compare these with yours. Printing is consistent, but again, the package molding is different. I'd say yours is probably legit. The one thing we can't tell from these pix is whether any of them are testing rejects.


At this point, I'm not convinced that your squeal problem is not caused by the charge pump. We should be turning over other rocks looking for the cause.

 

[flippy69]

You know, I have another pedal I was building a few months ago that I gave up on for the same reason, the charge pump came from the same batch. Now I’m thinking that I did in fact get a fake batch of chips. And it looking at the photo you provided I see that my chip is a lot different in fact it doesn’t even have printing it looks like the writing on it is molded or etched. I think that I got bad chips.

 

[Chuck D. Bones]

You'll know for sure when you swap it out for one from DigiKey.

 

[flippy69]

You'll know for sure when you swap it out for one from DigiKey.

Exactly!! I cannot thank you enough for the help. I’ll let you know ASAP, Cheers.

 

[flippy69]

Here are pix of two TC1044S charge pumps.
The one on the left was purchased from Small Bear in Sept 2019. My confidence level is 90% that this part is legit. Small Bear is not a factory authorized distributor, but has a history of selling legit parts.
The one on the right was purchased from Mouser in July 2019. My confidence level is 99% that this part is legit. Mouser is a factory authorized distributor.
View attachment 9093
Note that the font, Microchip logo and positioning on the face of the part is consistent. The differences in the package molding is of minor concern. The same factory will have a large number of package molding machines and they may not all be identical. The finish and color of the packages are consistent.

Now compare these with yours. Printing is consistent, but again, the package molding is different. I'd say yours is probably legit. The one thing we can't tell from these pix is whether any of them are testing rejects.
View attachment 9092

At this point, I'm not convinced that your squeal problem is not caused by the charge pump. We should be turning over other rocks looking for the cause.

Problem solved! I just got the chip from Digikey and this Kliche sounds like a klone. Tons of volume and headroom, super quiet, no trace of oscillation. I notice that the bad chips had no little indentation on the top left. Here is the beautiful and perfectly working chip.