Another fuzz idea...

[Dragonfly]

heres another idea i had...no breadboard handy, so it hasnt been tried, and the values are "guesses", but could prove to be interesting....i'd suggest "trying" a .1 or .047 for the "unmarked" caps....

hopefully i'll get to breadboard this soon....

any ideas on improvements or changes.... ?  Marty ? RG ? Mark ? anyone ?

[Steben]

Just some thoughts...
You could raise the 47k to ground at base Q1. Gives you more input impedance, less high roll-off...
You could place the typical mellow FF mod 100-220-470pf cap from collector Q3 to base Q2...

I never place clipper or diodes whatsoever after a Fuzz Face. Don't know...

[MartyMart]

Somehow, I can't see this sounding any better than your "smooth silicon fuzz"
which, BTW sounds fantastic and very "Ge" IMO.
I've mucked around with several of these, and they just end up as an "OK" fuzz
but with tripple parts count  !!!
If you lost the "tone"control, then the recovery stage can go and perhaps Joe Gagans
idea of taking a pot apart and removing a few mm's of track, could be used where the
diodes connect to the "sizzle", so when dialed back they are removed from the circuit as
the "path" is cut  ?
Not trying to put you off Andy, and perhaps I'm missing the point of this, I just have not
had much success with "many stages" in a circuit like this.....   

Marty.

[Dragonfly]

Just some thoughts...
You could raise the 47k to ground at base Q1. Gives you more input impedance, less high roll-off...

worth a try

You could place the typical mellow FF mod 100-220-470pf cap from collector Q3 to base Q2...

i considered that, but decided against it...dont know why really....could put it on a switch....

I never place clipper or diodes whatsoever after a Fuzz Face. Don't know...

the way the diodes are set up should be easy to dial in just a "bit" of 'em...and still have plenty of output

[Dragonfly]

Somehow, I can't see this sounding any better than your "smooth silicon fuzz"
which, BTW sounds fantastic and very "Ge" IMO.
I've mucked around with several of these, and they just end up as an "OK" fuzz
but with tripple parts count  !!!
If you lost the "tone"control, then the recovery stage can go and perhaps Joe Gagans
idea of taking a pot apart and removing a few mm's of track, could be used where the
diodes connect to the "sizzle", so when dialed back they are removed from the circuit as
the "path" is cut  ?
Not trying to put you off Andy, and perhaps I'm missing the point of this, I just have not
had much success with "many stages" in a circuit like this.....   

Marty.

i thought the tone control might be interesting, as its more of a variable low pass filter.....it shouldnt really "need" the recovery stage...i added the stage more because i like the sound of a boost after a fuzz

my "guess" is that this should be quite variable in sound, using the low pass and the biases...but i havent built it yet, so who knows.....

[Steben]

Just some thoughts...
You could raise the 47k to ground at base Q1. Gives you more input impedance, less high roll-off...

worth a try

btw: Max input impedance is about 100k [(490+25ohms)*hfe], but you would need very high bias values (parallel).

A tone control in front is "tryable" too... Especially a BMP style control...Let's you dial between treble boost or FF tone suck emulation. Don't worry about tone control attenuation: with a buffer instead of the subtle gain, you wouldn't loose too much signal. A buffer direct after a guitar works as a gain, since it cancels loading.

[brett]

Hi.
Actually, Zin is less than 47k.  If the Zin of the pot and Q1 is 100k, then it's substantially less.

Overall, it looks like a workable concept.  Do you need three stages before the tone control?  Would 2 do? Also, you might want to use 3 diodes, too.  Some of us prefer asymetric clipping, and it's so easy in this type of circuit.

A simple circuit that you might check out is the Bosstone.  It's different, but I suspect achieves something similar.  It uses an active load on a 2N3904 type transistor to double it's gain and lower the output impedance.  Then it's off to a couple of diodes to ground for clipping.  For some reason, that circuit has always sounded better to me than Distortion+ or Rat type circuits.

Cool concept.

[Steben]

Actually, Zin is less than 47k.  If the Zin of the pot and Q1 is 100k, then it's substantially less.

Well euhmmm... wasn't that clear? I said max potential is 100k.

[PenPen]

DragonFly,

Please let us know when you get one of these built, and how it sounds. It looks really cool, especially the odd feedback-biasing on Q2 using the emitter of Q3. I don't think I've seen that before, and I like the looks of it. I'm really interested in how this turns out.

Once I get settled in the new house and get my workbench set up I may try building this, after I finish my Rat project. Which I still owe you a perf layout for too, as soon as I get my parts order in I'll verify my layout.

[Gus]

Look at Doug H's hot Si

[Khas Evets]

It looks really cool, especially the odd feedback-biasing on Q2 using the emitter of Q3. I don't think I've seen that before, and I like the looks of it.

Fuzz Face??

[PenPen]

It looks really cool, especially the odd feedback-biasing on Q2 using the emitter of Q3. I don't think I've seen that before, and I like the looks of it.

Fuzz Face??

Errr, yea. Never built a FF nor did I look that closely at the schem since I started building.

I'm going to stop talking before I put my foot in my mouth again.....

[Dragonfly]

Errr, yea. Never built a FF nor did I look that closely at the schem since I started building.

I'm going to stop talking before I put my foot in my mouth again.....

essentially, its a bias-able fuzz face sandwiched between two boosts (one w/ a variable bias) and adss a low pass filter and controllable clipping diodes....

[Doug_H]

Look at Doug H's hot Si

For reference: