2 japanese circuits from Moonn

[Fuzzonaut]

I grabbed these 2 PCBs just because they seemed interesting.

First up is something based on a schematic found in the Experimentalists Annonymous DIY Archives, labelled as "old school fuzz", this one:

Now, if anybody can tell me, what the "Noise Controll" (5kB) actually does, that would be welcome. And why would Nils change it to 50KB?

Well, anyway, it is a cool fuzz on guitar, does a great Garage/Surf/Trash sound. On bass, it's nice'n'nasty but a bit thin though, for my taste at least.
Japanese B movie film poster for graphics. I love those robots.




And then, there's this weird monstrosity: Honey Special Fuzz, apparently from 1968 ...
No idea what they were on while designing this, I mean you have 13 transistors, 2 transformers and a shitload of other components in there and all you get as far as potentiometers go, is a volume control at the very end of all that circuitery! Otherwise everything is fixed!



But what is it? - Well, actually, it's 2 things:
- a fuzz circuit, à la Superfuzz and
- an autowah (?)
The toggle switch let's you choose the routing, so to speak:
- up = left foot switch kicks in both: fuzz into wah (right footswitch does nothing)
- down = left footswich kicks in fuzz only, right footswitch activates wah only, while taking the fuzz out
At least, I think that's what's happening ...

The fuzz is pretty beefy and cool, the wah is kinda wonky, but then, I have zero experience with wah circuits, so what do I know?
I tried a lot of transistors in the wah section to get a presumably nice wooshy movement. I also fiddled with the transistors of the output section to get more volume because it got just a bit over unity when dimed. But that didn't really help, so I just added a LPB-1 (on vero, with 220N caps and 12k instead of 10K) after it and now it roars!

Another Japanese B movie poster for graphics. Robots carrying women ... a classic!

 

[Coda]

Satisfactory work. That Old School Fuzz looks like they threw a little of everything in there. I may have to breadboard one...

 

[lrgaraujo]

I might be completely wrong here, but a little simulation on LTspice suggests the noise control kind of controls how good of an octave you can get (versus a very f*cked up fuzz). It is changing the bias on both npn transistors. If you have matched transistors, you might get the best octave with the control at noon. A 50k pot instead of a 5k would allow for more extreme sounds, I think.
Then again, I might be completely wrong

 

[PedalBuilder]

The first circuit is basically an Ibanez Standard Fuzz, which in turn is a modified Super Fuzz with an input stage based on a single JFET replacing the two BJT input stage in the Super Fuzz (and some other minor component changes). The "noise control" is used to balance the biasing of the differential pair that is used for octave generation. In many Super Fuzz/Standard Fuzz builds, it's an internal trimmer to compensate for imperfectly matched transistors, but some builders make it an external control and use it as an octave control, which I'd guess is being done here. Nice builds!

 

[Fuzzonaut]

I might be completely wrong here, but a little simulation on LTspice suggests the noise control kind of controls how good of an octave you can get (versus a very f*cked up fuzz). It is changing the bias on both npn transistors. If you have matched transistors, you might get the best octave with the control at noon. A 50k pot instead of a 5k would allow for more extreme sounds, I think.
Then again, I might be completely wrong

This circuit is basically an Ibanez Standard Fuzz, which in turn is a modified Super Fuzz with an input stage based on a single JFET replacing the two BJT input stage in the Super Fuzz (and some other minor component changes). The "noise control" is used to balance the biasing of the differential pair that is used for octave generation. In many Super Fuzz/Standard Fuzz builds, it's an internal trimmer to compensate for imperfectly matched transistors, but some builders make it an external control and use it as an octave control, which I'd guess is being done here. Nice builds!

Thank you both for sharing your thoughts and knowledge. I really appreciate it.
This forum always delivers!