Fuzzy Foxx switch and diodes questions

[iamjackslackof]

Howdy gang,

Got a couple questions about the Fuzzy Foxx.

1. My reading of the schematic says that D1and D4 produce the octave, and D2 and D3 are the clippers. Is that accurate?
2. How closely matched to the octave diodes need to be to each other, and is there a range they should be in?
3. The guy I'm building this for wants a stomp switch for the octave switch. I'm not certain how to wire a 3PDT in this case. I'm guessing I would just connect one side of the 3PDT to the existing switch pads in the same order? I imagine I could order a SPDT stomp switch, but I have plenty of 3PDT on hand already. I also have SPST stomps I normally use for relays, could that work here too? I doubt it, since they're usually momentary and only have 2 poles, right?

Thanks!

 

[iamjackslackof]

Anybody? Someone here knows, I know it!

 

[DGWVI]

Howdy gang,

Got a couple questions about the Fuzzy Foxx.

1. My reading of the schematic says that D1and D4 produce the octave, and D2 and D3 are the clippers. Is that accurate?

This is correct

2. How closely matched to the octave diodes need to be to each other, and is there a range they should be in?

The range doesn't particularly matter, but I prefer lower vf diodes, with 1N5817 Schottky being my favorites.
For the best upper octave performance, matching the diodes and surrounding components is recommended, with the list denoting the pairs to be matched

1. R4 / R5
2. C3 / C4
3. R9 / R11
4. D1 / D4

It's not terribly important to perfectly match these bits, but it will give the most prevalent octave sounds if they are.

3. The guy I'm building this for wants a stomp switch for the octave switch. I'm not certain how to wire a 3PDT in this case. I'm guessing I would just connect one side of the 3PDT to the existing switch pads in the same order? I imagine I could order a SPDT stomp switch, but I have plenty of 3PDT on hand already. I also have SPST stomps I normally use for relays, could that work here too? I doubt it, since they're usually momentary and only have 2 poles, right?

3PDT will work as you've described, and you can use either of the unused poles for LED indication.

 

[MobyOctopad]

I remember reading somewhere - probably an older post in the forum - that you want the octave diodes to be within something like .01v of one another to maximize the octave effect. That might've been for something like a Green Ringer, though, so not sure if that applies to the Fuzzy Foxx. Hopefully someone else can chime in.

 

[Nostradoomus]

The range doesn't particularly matter, but I prefer lower vf diodes, with 1N5817 Schottky being my favorites.

5817 gang!

 

[iamjackslackof]

Thanks for all the replies!

 

[jesuscrisp]

Won't stop the guy probably, but I don't think the same tone knob setting sounds good with octave on and off.

 

[DGWVI]

Won't stop the guy probably, but I don't think the same tone knob setting sounds good with octave on and off.

This is a good point, and since you're using a 3pdt for the octave, it'd be easy to implement using the last pole of the footswitch -


You'll want to double the Tone pot value to 100k