HI, A while ago, I built an MKII professional using the pcb layout and schematic on Fuzz Central. It sounds great, but it's hissy as hell. I changed out all the transistors, and mounted everything (except the caps, leads were too thick) into sockets. The voltages are about 9, 0.7, and 4.5 on the collectors of Q1, Q2, and Q3, respectively. The hiss seems to increase the longer I play. What could be the problem?
Thanks, Aaron
P.S. I used carbon comp resistors (that may add to the noise?), sprague orange drops, and sprague atom capacitors. Also, I have a diode, a 1M pulldown resistor, and a 47k (instead of 100k) q2 collector resistor installed.
Do you know how much gain your first transistors have? A germanium circuit can get a ton of noise sometimes. I have a vox treble booster and any amplifiction put after it, is met with plenty of noise. Its gets so bad sometimes, I started using a commercial noise reducer. Also you might have leaky transistors or some kind of biasing problem. Check out RG Keen's site. He has a ton of information on how to deal with germanium transistors used in fuzz. tfc.
Yeah, Q1 is 67, Q2 is 69, and Q3 is 100. It's pretty ideal, and this isn't the first set I've tried. I'm wondering if it could be the cap that connects the collector of Q1 with the base of Q2. Thoughts?
I don't know if its that capacitor or not. You should check/replace all the parts carefully but pay careful attention to the first two stages. I however, use active and sometimes passive filters on the outputs. Helps, but its not a cure all. Reality is, its just a seriously bad problem. tfc.
Sometimes the problem is the emitter direct coupled to ground. I put a small 10-100 Ohm resistor in my clones and have less noise. Also I use a 2000-4000uF from + to -. Sometimes the transistor is bad, so trying with another may help.
