First of all many thanks to Philip for his great site full of cool projects/ schematics and useful information!
Few days ago I finished un NPN Tonebender MKII clone ( Mindbender).I desided to use Ge/Si/Si configuration for Q1,Q2 and Q3 respectively.I was not satisfyed by the sound of the Ge tranyes at Q2 and Q3 that"s why I did this change. The sound with this configuration for me is thighter, has more definition and the sustain is longer.There is a lot of bite in it and I like it a lot! Thogh thete is a noticable frequency/amplitude oscilation at maxed fuzz settigs especialy on A of the 4-th string most noticable when the tone starts to decay. Gains of the Q's are right- 76,75,105, voltages too in acceptable dimensions.I tried various ways to get rid of this oscilation with no considersble success.One thing works- a 220 ohm resistor between E of Q3 and Fuzz Pot but it kills the bite and so the magic of the sound disappears and this is no solution for me at all!It simply works by reducing the gain.100 ohm resistor at E of Q2 does not help almost at all even higher values do not do.This oscilation exists even with all Q's being Ge too. I even tried combinations of Ge, Si, FET and MOSFET's at Q2 and Q3 positions. They work but my favorite is GE/Si/Si and there is still the above mentioned oscilation in all of them at highest setings of the fuzz pot. Is there solution for this problem?
