Jen (Gretsch Playboy) - Harmon Booster

Nightraven has taken his apart and offers some description of the tone of this strange unit: "it's basically an overdrive pedal that borders on fuzztone with the controls dimed and having a dirty amp to start with. very underrated IMHO - i think it's loads better than Tubescreamers and the various copies."

For a better idea of how it sounds check this demo video out:

Soniciv also uploaded a schematic for the unit:

8 transistors! Yep, they aren't all gain stages though as you can see there's quite a few buffer stages in there with a big muff type tone control at the end of the circuit (with a buffer either side of it!)...

And here's a great vero from Sinner over at turretboard.org:

For more info check out the freestompboxes.org forum topic out: http://freestompboxes.org/viewtopic.php?f=19&t=16284