# Kliche Mini has High Frequency Noise



## Haigster (Nov 5, 2020)

Not sure if anyone has come across this problem, I've built two Kliche Mini pedals, they sound amazing and I've been using them for months. But my 50 year old ears didn't hear the high frequency noise that was being generated when both these pedals are activated.

I only noticed when I was playing with another younger (under 30 year old) bassist and he said he could hear it loud and clear. I recorded a loop into my looper and 1/2 speed revealed a squeal at around 8k, so the original sound is up in the 16k zone.

I tried shielded cables for input and output jacks but that didn't make a difference. Here's the gut shot from one of them.



Thanks for any help


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## Robert (Nov 6, 2020)

The most likely cause is the charge pump IC.   

Make sure the part number is TC1044*S*CPA and not TC1044CPA.      The S version operates at a higher frequency outside of the audio spectrum.


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## Haigster (Nov 6, 2020)

yep, both have the TC1044*S*CPA. maybe I'll buy a few more and exchange them. thanks


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## Robert (Nov 6, 2020)

You can also use an ICL7660SCPA.

One that I haven't tried yet is the TC7660HCPA.  This one runs at 120KHz (vs 45KHz) so should be _well_ beyond the range of human hearing.


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## Nostradoomus (Nov 6, 2020)

Haigarmen said:


> yep, both have the TC1044*S*CPA. maybe I'll buy a few more and exchange them. thanks



Where do you get them? There’s fakes out there for sure!


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## Robert (Nov 6, 2020)

A few folks here have reported issues with some from Mouser, of all places.


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## Nostradoomus (Nov 6, 2020)

It’s true...even the big guys slip up occasionally!


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## Germanium Transistors (Nov 6, 2020)

Haigarmen said:


> Not sure if anyone has come across this problem, I've built two Kliche Mini pedals, they sound amazing and I've been using them for months. But my 50 year old ears didn't hear the high frequency noise that was being generated when both these pedals are activated.
> 
> I only noticed when I was playing with another younger (under 30 year old) bassist and he said he could hear it loud and clear. I recorded a loop into my looper and 1/2 speed revealed a squeal at around 8k, so the original sound is up in the 16k zone.
> 
> ...


Dude try ferrite beads.  Also MG Chemicals makes coatings you can paint or stay into your enclosure, that are extremely effective.  Nickel Foil (not so much copper of aluminum).  It’s all about “electrical permeability” of the material in the finally analysis.  Hope that’s useful information.  After 18 years of actively building, sometimes I had to learn the hard way, I feel your pain.


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## Germanium Transistors (Nov 6, 2020)

Germanium Transistors said:


> Dude try ferrite beads.  Also MG Chemicals makes coatings you can paint or stay into your enclosure, that are extremely effective.  Nickel Foil (not so much copper of aluminum).  It’s all about “electrical permeability” of the material in the finally analysis.  Hope that’s useful information.  After 18 years of actively building, sometimes I had to learn the hard way, I feel your pain.


Oh and if available steel GREATLY outclasses Aluminium


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## Haigster (Nov 6, 2020)

Nostradoomus said:


> Where do you get them? There’s fakes out there for sure!


I believe these are from Tayda, where else would you try?


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## Nostradoomus (Nov 6, 2020)

I believe there’s been some issues with Tayda’s in the past...but not every time. I get mine at DigiKey. They usually give off a distinct 10khz whine so if it’s more in the 16khz range that may not be your issue.

I had a similar problem with my Byrdhouse compressor...it doesn’t have a charge pump but when I flick the switch to the treble setting it whines like a banshee! Never figured it out.


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