Tone bender clone negative ground wiring help please!

[ray jones]

Hello everyone,

I have little very little electronics knowledge but have built and modded a few pedals, in a paint by numbers kind of way!
I want to build a 3 knob tonebender for bass from a kit but would like to be able to daisy chain it. Aside from using NPN transistors is it just a matter of swapping the red and black wires from the power input & battery, also I'd have to change the direction of the diodes / caps?
Here's a wiring diagram, http://www.musikding.de/popup_image.php/pID/888/imgID/0
pcb layout http://diy.musikding.de/berichte/eff/derbender/bilder/layout.gif
schematic http://www.musikding.de/popup_image.php/pID/888/imgID/0
Also any transistor recommendations would be fantastic!

[petemoore]

1  I would start with an NPN Neg Gnd. Schematic [NPN tranny's].
2  Or of course there's the other good option, tried and true, the PNP Pos. Gnd Tonebender...recommended for use with it's battery or other floating power supply.
3  Then there is a PnP/NEg Gnd. circuit, which has been a source for quandries, disappointments, failures, re-do's to some other PS scheme, and good sounding Tonebenders.
  Choose one of the top two that are known to always work, or try your luck with #3. 

[anchovie]

Schematics for NPN germanium and silicon versions here: http://www.generalguitargadgets.com/index.php?option=content&task=view&id=84&Itemid=112

[petemoore]

  Looks like a positive Gnd. circuit to me. I see a + of an electrolytic cap and a diodes' anode connected to an emitter.
  It's a bit of a hard read on the PCB though for me.
  Perhaps you can see the schematic, it's a picture of a board and pots/wiring again for me.
  Sticking with PNP germanium...
  Or convering to NPN Germanium...
  is best done with selected transistors for Hfe gain / leakage.
  Moving to NPN, take a look at 'Hot Silicon', or 'Silicon Tonebender', Q1 base requires a different bias iirc, [other mods].