freestompboxes.org

Hi,
PNP transistor circuits. Needs positive ground. To make this, and still to be able to use standard 9V dc adapter we are uisng 7660 reverse voltage converter
My question is: why? Why we can't just replace PlUS with ground on schematic and design layout with it? Like Lovepedal Silicon Fuzzmaster? (BTW, why this pedal doesn't just use 3904 instead of 3906 and reverse voltage?)
So, what are advantages and disadvantages of both solutions to power PNP-based circuits? Because I don't believe that simpler idea is not in use because is not very popular.

Because of the power adapter.
You can use a battery or a separate adapter or an isolated power supply.
If you use one power supply and daisy chain all your negative AND positive ground effects, as soon as you plug a guitar cord from a negative ground pedal to one with a positive ground, you will short out the power adapter.

Hmmm, can't find a way to edit posts. Accidently hit submit instead of preview...
Anyway, as far as being able to swap the ground and positive connections as in the Lovepedal, that does NOT always work, especially with older, original designs.