electro harmonix graphic fuzz schematic request

[beatnik]

hi guys, i want to modify the power supply of my graphic fuzz

i can't find the schematic of the pedal, all threads in the forum have dead links

anybody has that?

[Mac Walker]

Had one in for repair recently myself.....

http://smokingtip.files.wordpress.com/2014/03/aagraphicfuzz.pdf

[beatnik]

thank you very much

i was thinking to add a 79L12 regulator to obtain -12V

i would power the pedal with a 18V DC power supply

do you see any inconvenience? maybe 18V is too much for 12V regulators?

[anchovie]

A negative voltage regulator doesn't turn a positive voltage into a negative one - it's for regulating voltages that are already negative.

[beatnik]

right now i see. should use AC supply instead! thanks

so at this point i don't think is worth modifying the circuit, since i would have to use a separate power supply anyway

but also i am thinking that maybe that power supply design is not the best? that 40V with those big resistor seem overkill

do you have any suggestion?

[PRR]

> that power supply design is not the best?

What is wrong with it?

It *IS* very strange. But it does give good regulated +/-12V at MINIMUM cost. The resistors throw about 1.3 Watts, but all power supplies have "some" waste. Next to your 50 Watt (even a 5 Watt) amplifier, the "waste" here is trivial.

And it works (right?).

[beatnik]

well, i was thinking maybe the resistor dissipate too much heat on the circuit board?