A fuzz circuit

[Gus]

Simmed a fuzz I built in the 90's.  Three controls, volume after the buffer, external bias control, output volume control
To the left of the input is a simple guitar cable sim.  You can adjust the coupling cap values to taste

[pinkjimiphoton]

thanks gus!

gotta try this one as well, LOOOOOOVE the OUSB!!

it's on the list!!

hopefully i don't screw it up too bad like i usually do!! lol

peace!

[John Lyons]

I have wanted to try this for years...
I'll print it out now and try to find some time.
Thanks Gus

[Toney]

Will definitely be giving this go.
cheers, Gus.

[LucifersTrip]

looks cool...like a fancy Bosstone (minus clipping diodes) with an emitter follower up front.

thanx for posting

[mac]

It looks like the 60s fuzz in jack's site, a circuit that is tricky to bias.
Based on that one I've built something similar but without the input buffer, AC187-126 transistors, drive pot at the emiter and clipping diodes. Same voltages, just different bias.
Worth the try!

mac

[Gus]

mac  

Yes it does look somewhat like the 60's fuzz.  I changed the transistors and offset the the emitter follower emitter voltage from 1/2 the supply,  Yes tricky to bias but because the output transistor is direct coupled to the 2nd transistor both change with the adjustment of R7.

As the R10, R11 volume control is turned up the bass is cut a little.  Often you want to cut some bass as you turn up the gain of a fuzz.

[mac]

I wrote a little application to calculate bias for this circuit, I mean q2,q3. As long as the emiter of q2 is close to the collector resistor, and there is a resistor at q3 emiter bias are pretty stable even for leaky germs.
(220k, 47k) (4k7, 10k) (4k7, 25k) should do it for germs of about hfe: 100 and leaking 300ua, like average ACxxx. That will put vc2 at 8.3v and vc3 at 3v. If not tweak the 220k.

Actually this and and my rangemaster are the only pedals I use 99% of the time...

I'd like to add that a 9v Heathkit sounds almost the same, calculator in my gallery (meaning q2,q3)

mac