I finally have completed my Tonebender family.  Just finished building a Mk. III version.  It ended being a somewhat exasperating experience.  As outlined in my post in the DIY section I had problems with the pedal just not having any fuzz sound or any sound at all after completing the build.  I spent many hours debugging the build and discovered that there was an error in the board with no connection between the collectors of the of Q1 and Q2 9a Darlington configuration) and gratefully concurred by Wilkie, displaying the great community on this board.  After making a jumper to connect the Q1 and Q2 collectors, I got fuzz, but not great sounding fuzz.  Very raspy with gating that occurred as I played higher up the fretboard.

Still convinced there was something wrong, I isolated the problem to be somewhere near fuzz pot.  The fuzz and volume pots pretty much acted as on/off switches with fuzz occurring only with the fuzz control full up and the volume control full up.  Looking at the schematic, the fuzz pot connected to a Ge Diode so I got out my magnifiers and there appeared to be a slight haze on the Anode side of the diode.  I hooked up my DCA55 semiconductor analyzer to the diode and got a reading that stated Unknown or Damaged part.  I don’t know why because I was careful soldering the part to the board, but may not have used a heat sing attached to the diode when soldering.  So I had to pull the Diode off the board and solder in a new one (with heat sinks clipped next the the glass part of the diode and another at the end of the leg).  Once soldered in, I confirmed I had a working diode with the DCA55.  Fired up the pedal – and glorious fuzz!  Really great sounding fuzz, which is somewhat similar schematically to the GuitarPCB Fuzzy Bee.  I wish GuitarPCB offered a Pumped Up version of the Mark III because I totally trust the GuitarPCB boards

Top of Pedal:

Jumpered parts on back of PCB:

The Tonebender Family.  Top row – Mark I, Mark 1.5 (Vox Version), and Mark II (second pedal I ever built).  Bottom row – Mark III, Supa Tonebender, and Hot Chilicon (supposedly a Si Tonebender circuit).  The Mark III, Supa Tonebender and Hot Chilicon (now Siracha fuzz) are GuitarPCB projects.