Master Fuzz Controls - Does This Sound Right?

[Idlebeach]

Hey gang! I just built the Master Fuzz and it sounds nasty (in a good way)! I am trying to determine if the controls are working correctly. I know some old circuits controls are kind of useless.

The volume works as expected. The fuzz knob also pretty much just acts as a volume - it gets much quieter (unusably quiet) when turned down. I tried looking at the schematic but I'm just not smart enough to tell if that sounds right.

Here's a link to the build doc/schematic if anyone is willing to take a peek.

Thanks!

 

[Coda]

One way to tell would be to take some measurements. Measure the voltage at the collector of Q2 with the Attack knob at max and at min. Ideally, you should have about full power (3v) at the max setting, and about half that at the min setting…

 

[Idlebeach]

One way to tell would be to take some measurements. Measure the voltage at the collector of Q2 with the Attack knob at max and at min. Ideally, you should have about full power (3v) at the max setting, and about half that at the min setting…

Does the Fuzz knob even do anything at Q2? Looking at the schematic it doesn't look like it would affect any of the transistors. It just looks like a loop with a cap and a resistor right before the volume. I'm still a schematic dummy though. That said - I can give it a shot later. Thanks for chiming in!

 

[Idlebeach]

I checked with a multimeter and as far as I could tell the voltage didn't change. I cleaned the PCB and reheated joints so I'm stumped. Switch works and the effect sounds right... just not sure about this Fuzz knob.

 

[Coda]

The attack control controls the bias of Q2…

 

[Idlebeach]

I'm not sure if attack and fuzz are the same but this doesn't have an attack control.

 

[Coda]

I'm not sure if attack and fuzz are the same but this doesn't have an attack control.

I apologize, I misread the title of the circuit. Looking at the correct one now…

Can you post some pics of both sides of your pcb?…

 

[Idlebeach]

I apologize, I misread the title of the circuit. Looking at the correct one now…

Can you post some pics of both sides of your pcb?…

No worries at all! I will attach a photo album HERE and the build doc/schematic again HERE. I tried replacing the Fuzz pot last night but it didn't make a difference. It still more or less acts like a second volume.

 

[Coda]

Looks like what you are experiencing is accurate to the OG…

 

[Nostradoomus]

Master Fuzz tone pot

Instead of the basically useless fuzz adjust control and mildly useful two position switch, wire it up like so for a sweepable low pass kinda thing. I also threw an MPSA18 in Q5 for a bit of oomph on the output. B50K Lug 1 —> switch 3 Lug 2 —> Fuzz 2 Lug 3 —> switch 1

forum.pedalpcb.com

Here’s a mod I did that may interest you. The fuzz adjust and switch are kinda useless so I made a tone sweep out of them instead.

 

[Idlebeach]

Master Fuzz tone pot

Instead of the basically useless fuzz adjust control and mildly useful two position switch, wire it up like so for a sweepable low pass kinda thing. I also threw an MPSA18 in Q5 for a bit of oomph on the output. B50K Lug 1 —> switch 3 Lug 2 —> Fuzz 2 Lug 3 —> switch 1

forum.pedalpcb.com

Here’s a mod I did that may interest you. The fuzz adjust and switch are kinda useless so I made a tone sweep out of them instead.

Cool! Did you also experience the Fuzz knob pretty much just being a second volume? Thanks for the post link, I will check it out!

 

[Nostradoomus]

I forget, I remember it just being redundant so probably haha.