The Tone Bender variant called “Boutique Bender” from generalguitargadgets, supposedly identical to the Fulltone SoulBender.
Update (24.01.2011): Just finished the Boutique Bender circuit (hooked up to a charge pump for negative voltage) and it works like a charm! Vero layout hereby verified.
Update (05.05.2011): Finally completed the Soul Bender. I’m not happy with how it turned out on the inside; once I added the transistors the board was much too tall to fit resting on top of the pots, so I had to push the pots aside to dig out some extra space. The wiring ended up a bit messy as a consequence. But it sounds nice and looks nice on the outside.
Update (20.10.2011): Fixed dead layout link.
Completed this recently, used a matched set of AC128 transistors from an online store here in Australia, 2 of them having factory installed heatsinks. Sounds great, thanks for the layout Harald!
I’m not knowledgeable enough to give you the correct answer. It is sitting between the signal path and ground though, so I’m guessing it’ll contribute some signal clipping at the very least.
Thanks for the answer Harald! May I ask you another question? Is the germanium diode there to offer temperature stability to the transistors or for another reason? Thanks, once again!
Hi gus. You’re right. Germanium transistors do vary a lot and you can get very different sounds out of this based on which ones you pick.
Your best bet is to visit http://www.smallbearelec.com; they sell ready-matched sets so you don’t have to do all the work. Get a “ToneBender PNP” set.
hi.. i read in a forum that i have to bias the tranzistors. i have no idea what this means and how to do it. i thought that it was all about soldering the right components to the board! did you bias the tranzistors? could you tell me what i have to do? thank you very much!!