I got some npn AC187 transistors and built both the Axis Face and the Mindbender over the holidays. I had the same problem with both in that I had to replace the 1K2 resistor with a 100K to get the voltage on the collector of Q2 to between 4 and 5V. (The voltage from the battery was measured at 9.2v). Has anyone else had this problem? I could have sorted it by replacing the 22k (20k on schematic) trim pot with a 220K but that would mean desoldering three lugs instead of two resistor wires. When I was trying to get the correct voltage with a pot it was obvious when it was getting close, the sound suddenly changed significantly and cleared up to how it should sound. I measured the resistance across the pot at 102K and when I fitted a 100k resistor was able to tune it in using the 22K trim.
Once the correct voltage was on the collector both pedals sound superb, and although similar they do have differences, I prefer the mindbender as it has more sustain. I took the mindbender to my bands last practice and was amazed with the sustain and how it sounded so much better with the valve amp than my transistor practice amp. Put a rangemaster clone in front for solos and you're away! Pure 70s/stoner rock.
The MindBender has always been one of my favorites. Since it's a combination of the best aspects of the ToneBender Professional MKII and the Supa Fuzz, it's hard to go wrong with it. It's also NPN so it can be powered by the same 9V power adapter that other modern pedals on a pedal board may be powered by.
The Axis Face Silicon Rev.3 (which will be posted soon) is another one of my new favorites...thick and warm, but not muddy and buzzy like other Fuzz Face-based circuits.
