Help with fine tuning Fuzz circuit Please

[sonolink]

Hi guys!!

I built 2 Fuzz circuits based on the classic Arbiter Fuzz Face. They both sound great BUT they have some noise I'm trying to get rid of. Both circuits are the same, only some components values are adjusted to tune them with the transistors used.

Circuit 01 is using a BC338 as Q1 and a 2N3904 as Q2. It sounds fantastic and has a huge range of colors and textures BUT, hisses all the time. Even when the guitar is unplugged.

Circuit 02 is using 2N3053s. Same as before only there's some high pitched noise and some static instead of hiss.

I tried modding both circuits after reading R.G.Keen and other posts but I can't get rid of those noises. I know that this circuits has an inherent bottom noise but I'd like to try to minimize as much as possible. I've attached schems and audio. The ground noise is mainly due to the circuits being breadboarded.

Circuit 01 schem:



Circuit 01 hiss:
View attachment Fuzz Test 04.wav


Circuit 02 schem:

Circuit 02 high pitched noise:

View attachment Fuzz test 01a.wav



All your ideas and suggestions very welcome as usual.
Thank you for your kind help
Sono

 

[micolas]

Hi guys!!

I built 2 Fuzz circuits based on the classic Arbiter Fuzz Face. They both sound great BUT they have some noise I'm trying to get rid of. Both circuits are the same, only some components values are adjusted to tune them with the transistors used.

Circuit 01 is using a BC338 as Q1 and a 2N3904 as Q2. It sounds fantastic and has a huge range of colors and textures BUT, hisses all the time. Even when the guitar is unplugged.

Circuit 02 is using 2N3053s. Same as before only there's some high pitched noise and some static instead of hiss.

I tried modding both circuits after reading R.G.Keen and other posts but I can't get rid of those noises. I know that this circuits has an inherent bottom noise but I'd like to try to minimize as much as possible. I've attached schems and audio. The ground noise is mainly due to the circuits being breadboarded.

Circuit 01 schem:

View attachment 146759

Circuit 01 hiss:
View attachment 146761


Circuit 02 schem:
View attachment 146758
Circuit 02 high pitched noise:

View attachment 146760



All your ideas and suggestions very welcome as usual.
Thank you for your kind help
Sono

I've built a lot of fuzz pedals (including germanium transistors which are noisier),
but I've never had this kind of accented noise.
Is the circuit on pcb or point-to-point?
Is it shielded in a metal box?
Did you use metal film or carbon film resistors?
Are the capacitors of good quality?
Did you accidentally ground loops?
Is the power supply with a transformer or from the battery (which type of battery matters)?
Is the fuzz fed from the same source as other pedals?
Is it connected to other pedals in front of it?

 

[dmp]

Agreed with micolas suggestions.
Also try shutting off all lights - especially any on dimmers - move away from any noise inducing electronics like monitors.
A Si pedal should be pretty easy to build quiet

 

[sonolink]

Is the circuit on pcb or point-to-point?I s it shielded in a metal box?

Right now it's on breadboard

Did you use metal film or carbon film resistors?

Metal film

Are the capacitors of good quality?

They are multilayer ceramic from Mouser

Did you accidentally ground loops?

I'll check but I don't think so

Is the power supply with a transformer or from the battery (which type of battery matters)?

The PSU is Truetone One spot.

Is it connected to other pedals in front of it?

The only elements present are the guitar, the circuit on breadboard+ PSU and the amp.

Also try shutting off all lights - especially any on dimmers - move away from any noise inducing electronics like monitors.

No lights on except one in the room

Thanks for your help
Cheers
Sono

 

[micolas]

@sonolink
You need to shield the circuit in a metal box connected to GND
Try powering it with a Duracell battery.

 

[sonolink]

@sonolink
You need to shield the circuit in a metal box connected to GND

Ok. I was breadboarding it to adjust several trannies and adjust their bias. I'm very happy with the sound now so I guess I could make a quick vero and box it in a 1590B to check if it's still noisy. I'll do that and report back

Thanks a lot for the help

Try powering it with a Duracell battery.

Any reason for it to be a Duracell. Won't a Panasonic do?

Cheers
Sono

 

[Brian Roth]

FWIW I hate Duracells. I call them DuraHell because they often end up leaking and corrode the guts of whatever equipment they are in. Energizers aren't much better.

Ray-O-Vac has been much better for me, but I'm sure other folks on the forum might disagree.

End of topic veer......

Bri

 

[sonolink]

Hi again,
I made a vero and boxed the circuit in an aluminium enclosure and the noise has diminished quite a lot.

Any ideas to get rid of what's left?

View attachment Fuzz 2.wav
Thanks in advance!
Cheers
Sono

 

[melmsmidth]

Hi, I built some Fuzz Faces although mainly germanium. Sometimes a bigger cap in C4 can help to lower the noise a bit (you can try to add it in parallel with the 100uF you have now for testing purposes). Start by doubling it.
You can try to raise the value of C5 and/or C6 too (not much, 150pF instead of 100pF maybe) to see if it helps, but it will surely affect the tone.
All fuzzes are very high gain so some noise is unavoidable, anyway, specially with Fuzz Faces and single coils.

 

[micolas]

Any reason for it to be a Duracell. Won't a Panasonic do?

Cheers
Sono

I read somewhere on a group many years ago that people recommended Duracell and Varta for these pedals. Maybe it's the internal resistance of the battery. I've used both with success, plus cheap Toshibas.

 

[micolas]

Hi again,
I made a vero and boxed the circuit in an aluminium enclosure and the noise has diminished quite a lot.

Any ideas to get rid of what's left?

View attachment 147631
Thanks in advance!
Cheers
Sono

Does battery-powered fuzz produce the same noise?

 

[micolas]

@sonolink
Did you use a Single-coil or Humbucker?
If you turn the guitar's volume knob to zero, does the noise get reduced?

 

[Voyager10]

Hi again,
I made a vero and boxed the circuit in an aluminium enclosure and the noise has diminished quite a lot.

Any ideas to get rid of what's left?

It's not 'normal' noise from the circuit itself; sounds to me like it's coming from the power supply, as it's not present in the guitar signal when the fuzz is bypassed.

 

[sonolink]

Hi guys,

Thanks a lot for your kind replies

@sonolink
Did you use a Single-coil or Humbucker?
If you turn the guitar's volume knob to zero, does the noise get reduced?

I tried both single coil and humbucker. Same thing. When the knob is turned to zero it used to make some noise so I added a resistor in series at the input. Noise is now gone.

Does battery-powered fuzz produce the same noise?

It's not 'normal' noise from the circuit itself; sounds to me like it's coming from the power supply, as it's not present in the guitar signal when the fuzz is bypassed.

Spot on Micolas and Voyager10! I just tried it with a battery: a regular alkaline Panasonic. The pedal is quiet as a mouse!!
The noise was happening with the pedal fed by a Ttruetone One Spot PSU. So I borrowed a hihg quality PSU and the noise is GONE!
A veeeeeery light hiss when everything maxxed out, by really veeeeery tiny.

I'm BAFFLED by this! The Truetone One Spot is supposed to be "triple filtered" and "clean"...obviously it's just a mediocre P.O.S.!
Any ideas on how to filter it properly? I'm using it to test most of my builds...

Thanks again for your help and suggestions
Cheers
Sono