Eric Johnsons Fuzz and the 4.5v at the collector of Q2 thing

[rousejeremy]

I love the tone he has here

http://www.youtube.com/watch?v=rIQMiJMb_Bw

   I've read he is using a Silicon Fuzz Face, I think I even read somewhere that his fuzz had BC183's in it. Whatever transistors are in his Fuzz Face on this track, Hendrix's "Love or Confusion", it sounds to my ears that the collector of Q2 is much higher than 4.5 volts. When I adjust trimpots to get that magic voltage, I always notice the higher voltages start sounding kinda like EJ. Single notes become more compressed sounding, thicker and richer with a good amount of, for lack of better words fuzziness and power chords have that on the verge of exploding buzzy warmth and roundness.
   His amps definitely have a lot to do with the his overall fuzz tone, but I was wondering what other builders have in mind when they HEAR the sound?

[PRR]

I think you are finding why Leo Fender biased his tubes near 2/3rd of supply voltage rather than the obvious 1/2.

[joegagan]

i have built a couple of silicon FFs, usually following gus smalley's recipe (with a few tweaks). i like the way Si sounds at 5.5 to 5.9 volts on Q2 collector as well.

http://www.diystompboxes.com/pedals/gusJH2mod.gif

[Gus]

A few people have posted here and even at AMPAGE in the mid late 90's about operating points of a ff type circuit.  I like to make a FF type with an external bias control for gated to compressed sounds.

[mac]

If you play with Q1 and Q2 collector voltages you'll have more tonal possibilities.
A lot is said about Q2 but almost nothing about Q1.

mac

[Caferacernoc]

Just like most people bias rangemasters at 5-7 volts. That's where the sweet sounds are. I find the same with jfet amp emulations. I like to bias them higher than 4.5 volts also. More even order harmonics I think.

[DougH]

I got a similar sound when I breadboarded the "Fulltone '70" schem that was floating around a few years ago, the one with the asymmetric diode clipping. That is supposedly the "rare purple version", whatever that means... IIRC it was a silicon FF with the diodes which helped "smooth" it out. Sounded very touchy-feely, a la EJ, to me.

[rousejeremy]

I just built the GGG Boutique '70s fuzz and found it's closer to the EJ sound than the GGG '60s fuzz. It was when I was tinkering with the trimpot on the '70 that I started wondering about the voltage thing.
Is the GGG '70 a clone of the Fulltone you mentioned DougH?

[DougH]

I just built the GGG Boutique '70s fuzz and found it's closer to the EJ sound than the GGG '60s fuzz. It was when I was tinkering with the trimpot on the '70 that I started wondering about the voltage thing.
Is the GGG '70 a clone of the Fulltone you mentioned DougH?

The GGG schem looks pretty similar to that schem that was floating around here in the 2003 time frame. I have not been able to find it since. I think I have it at home.