Klon Clone Creating High Pitch Whine/Squeal Noise

[VoxLove]

Hey Guys,

This is my first post hopefully someone can shed some light on this issue.
I have a klon clone thats giving me a really high pitched squeal when I activate the pedal. The noise gets louder as I turn the treble knob up (treble sweep allows for it to be completely cut off around 9 o'clock) and increases as I turn up the volume pot (no noise at zero on volume pot). This is while I have my guitar turned down, but it also exists when there is no input cable plugged in, just output to amp. I use a Boss Adapter 240v to 9v by itself, and have tested it on a pedal power supply that is isolated (min AC ripple). I have searched many threads on this and other forums but and unable to find out if it's A) RF noise (I live close to an FM radio station) B) AC Ripple that is being amplified by the charge pump in the circuit. Has anyone had a similar problem with a klon clone circuit? I was thinking that a capacitor to ground from the input lugs of the circuit would help, tried a 33pF all the way to 100pF but noise is still there...

Cheers,
James!

[Marcvv]

Hey Guys,

This is my first post hopefully someone can shed some light on this issue.
I have a klon clone thats giving me a really high pitched squeal when I activate the pedal. The noise gets louder as I turn the treble knob up (treble sweep allows for it to be completely cut off around 9 o'clock) and increases as I turn up the volume pot (no noise at zero on volume pot). This is while I have my guitar turned down, but it also exists when there is no input cable plugged in, just output to amp. I use a Boss Adapter 240v to 9v by itself, and have tested it on a pedal power supply that is isolated (min AC ripple). I have searched many threads on this and other forums but and unable to find out if it's A) RF noise (I live close to an FM radio station) B) AC Ripple that is being amplified by the charge pump in the circuit. Has anyone had a similar problem with a klon clone circuit? I was thinking that a capacitor to ground from the input lugs of the circuit would help, tried a 33pF all the way to 100pF but noise is still there...

Cheers,
James!

Hi James,

What voltage doubler chip did you use? the 7660 is known to be the source of whine. In that case use a Max 1044 or a 7660s or equivalent.

And in case you are using one of these two check if pin 1 and pin 8 are connected.

Marc

[mikemaddux]

Hey Guys,

This is my first post hopefully someone can shed some light on this issue.
I have a klon clone thats giving me a really high pitched squeal when I activate the pedal. The noise gets louder as I turn the treble knob up (treble sweep allows for it to be completely cut off around 9 o'clock) and increases as I turn up the volume pot (no noise at zero on volume pot). This is while I have my guitar turned down, but it also exists when there is no input cable plugged in, just output to amp. I use a Boss Adapter 240v to 9v by itself, and have tested it on a pedal power supply that is isolated (min AC ripple). I have searched many threads on this and other forums but and unable to find out if it's A) RF noise (I live close to an FM radio station) B) AC Ripple that is being amplified by the charge pump in the circuit. Has anyone had a similar problem with a klon clone circuit? I was thinking that a capacitor to ground from the input lugs of the circuit would help, tried a 33pF all the way to 100pF but noise is still there...

Cheers,
James!

Hi James,

What voltage doubler chip did you use? the 7660 is known to be the source of whine. In that case use a Max 1044 or a 7660s or equivalent.

Marc

+1

[MartyMart]

+1 for the Max 1044 in this case.
Also do some power filtering at the circuit 9v input and keep the build "clean"

MM

[VoxLove]

Thanks for the replies everyone was very helpful!

Will try some caps/resistors on power section to filter the signal
Cheers,
James

[bean]

A TC1044 also works well here, and is cheaper ~ $1.25 from Mouser.

[eddie_bowers]

I have the same noise/whine issue on a boost build with a TC962 charge pump.
I might try the TC1044, but I wanted to make sure I could run the frequency at 45kHz with a 9v supply.
This part of the data sheet made me question:

"It may be desirable in some applications (due to noise or
other considerations) to increase the oscillator frequency.
Pin 1, frequency boost pin may be connected to V+ to
increase oscillator frequency to 45kHz from a nominal of
10kHz for an input supply voltage of 5.0 volts"

Can I use a 9v supply AND 45kHz?

-Eddie

[Cliff Schecht]

You guys are pushing it with your low switching frequency charge pumps. I'd be looking for at least 100 kHz+ in something that was going in an audio system.

[eddie_bowers]

The problem is nothing does 100kHz+ over 5 volts (that I can find).
I guess i'm going to give the TC1044 a try.

[Gurner]

Very current for me this topic! (becuase just this afternoon, I was reading associated datasheets)

I need a switched capacitor inverter, & the 7660 kept coming up on forum searches - but then I saw on the datasheet that the osciullator frequency is 10Khz....oh,oh.

Anyway, I managed to find a variant that allows you to select a higher frequency (45Khz)...

TC7660SCPA  (& in british dosh...it's a quarter of the price vs a MAX1044)

You guys are pushing it with your low switching frequency charge pumps. I'd be looking for at least 100 kHz+ in something that was going in an audio system.

100khz?!! Are you a bat that can type by any chance?

25khz is fine.

[jkokura]

It has to do with the TYPE of charge pump used.

Using a 7660SCPA is fine, but you probably got a 7660CPA. I did the same thing, switched to a TC1044SCPA and it's fine.

Jacob

[Cliff Schecht]

Very current for me this topic! (becuase just this afternoon, I was reading associated datasheets)

I need a switched capacitor inverter, & the 7660 kept coming up on forum searches - but then I saw on the datasheet that the osciullator frequency is 10Khz....oh,oh.

Anyway, I managed to find a variant that allows you to select a higher frequency (45Khz)...

TC7660SCPA  (& in british dosh...it's a quarter of the price vs a MAX1044)

You guys are pushing it with your low switching frequency charge pumps. I'd be looking for at least 100 kHz+ in something that was going in an audio system.

100khz?!! Are you a bat that can type by any chance?

25khz is fine.

25 kHz is too slow. If you aren't careful, that 25 kHz will heterodyne with other switching devices in your circuit and produce unwanted artifacts. If you are running a 20 kHz BBD for example, you can (and if you aren't careful will) get artifacts at 5 kHz (difference) and 45 kHz (sum, not of concern here). To most people under 70, 5 kHz is quite audible. Throw in a high gain circuit like in most distortions and you suddenly have a 5 kHz bleed-through that you have to deal with. It's better to choose your switching frequency at least twice that of the highest signal of interest in order to avoid audible aliasing.