Anybody built one before and have any tips? Sorry for the noob post (hence my handle), I'm just trying my hand at something new! Thank you!
I just dug out my notes on the Supa Fuzz. This DAM post was the most helpful. The moderator is a master of TB MKII/ Supa Fuzz:http://dam.10.forumer.com/viewtopic.php?t=779&highlight=collector+voltage
his post regarding gains and Q3 collector voltage:
On vintage units it varies from around -7.6V - -8.9V.
Even seen em with 9.1V! I take measurements with Zinc Carbon batteries which are around 9.6 Volts when fresh. The original batteries used in the MKII's and its variants were PP4's (Eveready 226) which also read high at around the 9.6V level.
Hfe levels are usually higher also. For example my '67 Supa Fuzz measurements...
Q1 - 174
Q2 - 208
Q3 - 194
I wrote a bunch of build reports as I was experimenting, but this is the final one:
I'm finally done (well, at least this build) and thanx to DAM's 200 hfe recommendation, I will barely have to make any change. It is absolutely killer with the 47K reduced to 36K...that's all.
I furthered my leakage tests with a much more controlled experiment. I substituted transistors with the same number (2SB459), almost same hfe, but different leakage...into each of the 3 slots. If you are going for straight out smooth saturated screaming fuzz, then low leakage won out in all cases. If you want a more lower gain, dirty, gated fuzz, then throw a higher leakage one into Q2. In Q1 a higher leakage reduced treble, sharpness, a little volume, and gave it a little fatter sound (not needed with 10uf input cap). In Q3, it reduced the overall attack.
In my previous version I had hfe 186, 193, 213 respectively ...but I upped the ante on the screaming fuzz by increasing Q1 further and keeping the leakage low. So, my final version is hfe 244, 193, 213 ...all leak under 150uF
If I want to get some gating, I can raise the C voltage on Q3 to around -8.3V. This way, you'll have a gate along with a rich, saturated fuzz. I can also get it to gate by lowering the voltage to around -2v, but the tone is way too thin and wimpy. If you want the gate to by dirty (with not nearly as much rich saturated fuzz) simply increase the leakage of Q2.
I like monster fuzz, so I'm going with low leak hfe 244, 193, 213 and a trim/cutoff on Q3 collector to give me from -6v to -8.5v
If I was going to mod it, I'd just put in a switch to alternate between a high and low leakage Q2. That way I could have everything: rich saturated fuzz, a dirtier low gain tone and gating with both.