anybody ever mess with the ESR Graphic Fuzz?

pinkjimiphoton · Post by **pinkjimiphoton** » 25 Jun 2013, 00:33

i was a-lookin' at this thing,

it looked stupidly easy, so i figured i bet it sounds like poo, so let's mutate it..

i TRIED to add "soft clipping" (hey, i haven't really messed with chip dirt too much) that was switchable in and out,

also added power supply filtering and polarity protection....

added in my "shift" control, for panning between two different kinds of diode clippers, and made it switchable in/out

and finally, a simple tone control just to take a little edge off if it's too brite.

some values may need to change some here or there... i'm sure. but this it the preliminary idea, do ya think it can fly?

or am i fatally messing this thing up... it looks kinda weird to me on the schematic, like, i think s1 just gives either fuzz or poor bypass. i just figure i'll TB the whole mess if/when i get it running.

suggestions welcomed!! (i know, breadboard it, pink!! lol)

anywho, cuz i'm obviously anal AND retarded both, i whupped up a vero for it too, which i believe should be good to go...
unless pins 1,5 and 8 on the 741 need to be grounded...

here ya go...

don't build this unless you're willing to debug it... like i am. usually. i think. (we can only hope)

NOT VERIFIED (yet) BUILD AT YOUR OWN RISK!!![/b][/i][/color]

opinions/advice/criticisms/etc welcomed!!!

help me make another pedal for a "stupid pedal trick"...

earthtonesaudio · Post by **earthtonesaudio** » 25 Jun 2013, 12:25

The original is powered by +/- 4.5V because the battery is floating.

This *may* impart something unique to the sound, or maybe not. One way to tell would be to build a more standard version without the floating supply, and bias it to +4.5V, capacitively couple in and out, etc. Then compare the two.

pinkjimiphoton · Post by **pinkjimiphoton** » 25 Jun 2013, 15:43

so, just use a voltage divider and take the half voltage as ground?

dave, you're way beyond my knowledge here...

tho i am thinking, without the feedback loop it may be a decent fuzz. the feedback loop is cool, but it's not something i'd use, and the uglyface does it better imho!

earthtonesaudio · Post by **earthtonesaudio** » 26 Jun 2013, 17:15

I would make a version like this to compare.

Note that besides converting to a single supply, I added a series 100 ohm resistor before the level control. This is to protect the opamp from having its output shorted to a low impedance when the volume is turned all the way down (in this case the low impedance is the 100µF cap; in the original it was ground). An alternative would be to wire the output level control as a voltage divider (this would be more standard) but then it would behave much differently (pots would be less interactive).