The MKIV is based on the three-knob Solasound Tonebender (versions 3 and 4).

The pedal features the following extras:

• PSU port
• on/off indicator (LED)

The transistors are a relatively rare combination: two Russian “Spaceships” plus one NOS Newmarket NKT MT57F “RED DOT”. This is the explanation I found on Analogman’s website:

“In late 2019 I realized that some Newmarket UK made NKT red dot transistors that were out of spec for Sun Face would work great in this pedal. I tried them and they sound great, a thick, deep tone with lots of harmonics and touch sensitivity. We can use one NKT in the third position along with Russians or Mullards in the pair, and offered these NKTs optionally till we ran out (about 100).”

I bought it second-hand but it was, and still is, in perfect working order and in a very good cosmetic condition. I’m selling because it really is surplus to requirement: I’m not a massive Tone Bender person and I have several pedals that cover similar territory (e.g. a Hudson MKII clone that I adore). I hope it goes to someone who will truly appreciate its unique vintage sound.