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

 

[Fuzzbuzz78]

I have a question related to adding a DPDT footswitch to engage the octave setting instead of a toggle. I currently have the DPDT footswitch wired up as outlined in the comments above. when I engage the octave fuzz, the signal cuts out for a split second. Is there anything I could do so the signal from the fuzz does not cut out when octave is engaged?

Cheers!

 

[Feral Feline]

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

My solution is a 2knob-job notched to accept a 4PDT.

The notches only chew some ground-plane; a daub of glue seals them up preventing shorts. However...


The 2KnobJob has changed again, and I don't know if the new ones can be notched out or not without wrecking a needed trace:

Even so, the PCB isn't needed as the switch can always be WIRED MANUALLY:
Pole 1 — Switch on/off the octave diode
Pole 2 & 3 — Switch the Tone pots
Pole 4 — LED indicator of whether octave & associated tone-control is in use or not.
Or whatever order of poles / function you prefer.


[Edit to add] Albeit, DGWVI's option seems more streamlined!