joyo voodoo fuzz high pitched whining on dc psu

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jdom84
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Post by jdom84 »

Hi I attempted the mod and it seemed to do nothing also an issue started where it cuts out momentarily when the octave pedal part is activated.

But the main issue is that there is a high pitched whining sound when the fuzz part is engaged and only when using the pedal with my 9v dc power supply. It is not an issue with the battery or when it is in true bypass.

It is a shame as I actually really like the fuzz distortion and it seems maybe mine didn't need the mod done after all? I noticed no difference except the problem when octave is engaged.

Anyway the octave effect is horrible IMO, I wish I could get it sounding more like my Behringer fs300 / Boss Hyper Fuzz.

So a few things but mainly what the title says as this makes it unusable.

Many thanks! (if you cannot tell I am pretty noob).

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ppluis0
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Post by ppluis0 »

Hi jdom,

The origin of this kind of noise are due the current power supply adaptors are implemented as switching mode units.
Try to find and "old school" adaptor that are transformer based and surely the noise goes away.

Cheers,
Jose

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plush
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Post by plush »

jdom84 wrote: But the main issue is that there is a high pitched whining sound when the fuzz part is engaged and only when using the pedal with my 9v dc power supply.
Apparently you are using SMPS with a switcing frequency within audible range. Such power supplies are not suited to be used with any audio equipment at all.
You need to use a specialized SMPS with a higher switching frequency (usually 40khz and higher) or to use a linear, transformer-based, power supply that has no switching circuitry in it.

There is always an option to partially mitigate the ripple (and most part of the noise), but you'll end up with lower voltage on psu's output.

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jdom84
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Post by jdom84 »

is that the big chunky oldskoool style transformers?
I do not have this issue with any other pedals I own and the PSu comes with good feedback on amazon is built and marketed for this purpose. ALso other people describe the same issue with the joyo voodoo fuzz.
Someone said about putting a capacitors across the filter input cap or something. To filter the noise out. It sounds like shielding or high piutched electrical interference. Doesn't sound like ground hum or radio interference. I will see if I have one of those older larger style DC PSU's and try it out. Think I may have one but have to repair that first before I can repair this! haha.

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plush
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Post by plush »

jdom84 wrote:is that the big chunky oldskoool style transformers?
I do not have this issue with any other pedals I own and the PSu comes with good feedback on amazon is built and marketed for this purpose. ALso other people describe the same issue with the joyo voodoo fuzz.
Someone said about putting a capacitors across the filter input cap or something. To filter the noise out. It sounds like shielding or high piutched electrical interference. Doesn't sound like ground hum or radio interference. I will see if I have one of those older larger style DC PSU's and try it out. Think I may have one but have to repair that first before I can repair this! haha.
There may be something wrong with the pedal itself, not necessary the psu, to be honest.
Joyo is notorious for their poor build quality.

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Post by jdom84 »

yeah thats what I am asking innit cuz I waNNA FIX IT :-)

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plush
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Post by plush »

jdom84 wrote:yeah thats what I am asking innit cuz I waNNA FIX IT :-)
You can't fix the thing if you don't know how it operates. Also, AFAIK, there is no proven schematic for joyo voodoo octave to compare your unit with.

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jdom84
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Post by jdom84 »

plush wrote:
jdom84 wrote:yeah thats what I am asking innit cuz I waNNA FIX IT :-)
You can't fix the thing if you don't know how it operates. Also, AFAIK, there is no proven schematic for joyo voodoo octave to compare your unit with.
I wanna fix the noise thats why I posted a question about that... So I dunno what your purpose is as you are not helping me at all.

Its problem solving, I have a voltmeter and a brain. I wanted some guidance in the right direction.

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Post by plush »

jdom84 wrote:
I wanna fix the noise thats why I posted a question about that... So I dunno what your purpose is as you are not helping me at all.

Its problem solving, I have a voltmeter and a brain. I wanted some guidance in the right direction.
To fix a problem you must locate its source.
Voltmeter won't help. You need at least an audio probe or oscilloscope.
Find a source of the problem, then we can decide how to fix it.

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