Sujet Pb de son sur un clone de Fuzz Face DIY

Citation : Fuzz face and biasing suggestions
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This is the schematic for a Fuzz Face pedal, a very
popular and simple pedal from the 1960's. There are two PNP
Germanium transistors, three capacitors, four resistors, and two
potentiometers. If you prefer maximum volume and maximum fuzz (what
else?) you can leave out the potentiometers, and just put in a 1K
resistor to ground at the fuzz pot. It is powered by a 9V battery,
with a positive ground. Jimi Hendrix used it, so it must be good.

There's not much to it, so you can make one if you want! The tricky
things are to get the transistors biased, and to make sure it is
loud enough. By fiddling with the resistors, you can probably
get it to bias properly. Here's one way. With a voltmeter,
measure the voltage at the collector "c" on the first transistor.
Make this be -0.5V under ground by adjusting the 33K resistor
(replace it with a trim, for example). With the fuzz all the
way on (the 1K pot) set the collector of the second transistor
to be at -4.5V to -5V or so by adjusting the 8.2K the same way.
Listen to make sure you get it right. When biased properly, the
Fuzz Face will seem to clean up and get brighter when you decrease
the volume on the guitar. To make the pedal louder put the volume
on the pedal all the way up (the 500K pot), and increase the 470
Ohm resistor until it is about right. In other words, use three
trims replacing the resistors in quotation marks; fiddle them back
and forth to get the voltages right, and the loudness right.

"470"
"8.2K"
"33K"

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