Fuzz Face problem

[mcasey1]

I recently assembled a fuzz face circuit, NPN silicon, pretty much like this one:

http://runoffgroove.com/multiface.html

Whenever the fuzz pot is reduced from full gain, the sound becomes quite muddy and dark.  I have yet to debug the pedal, as I dont think the problem merits a debug.

I am using a .01uf cap for in and out caps.  Q1= 2n5088, Q2=2n7000

If it is an inherent problem in the FF circuit, which I dont think it is, would there be a solution, such as a cap attached from the pot to ground?

[tcobretti]

It's not inherent in all FFs.  However, most people who play FFs leave the fuzz knob dimed anyway and just control the amount of fuzz with the their guitar's volume knob.  Many people choose the transistors carefully with the intent of making the fuzz interactive with the guitar's volume knob.

[mcasey1]

I would probably like to omit the fuzz pot altoghter, so it would be as if pot was dimed.  How would I go about doing this?

[aron]

set the pot the way you like. Then disconnect the pot. Measure from outer lug to wiper (using ohms setting on your meter). Write the value down. Now replace the wires that connected to those lugs with a nearest value resistor.

Do the same for the other lug to wiper.

Note that the resistors will "meet" at the wire that used to be connected to the wiper.

|-------------- upper lug wire
<
<
<
|
|-------------- wiper wire
|
<
<
<
|
|--------------- bottom lug wire


for the above diagram, the following is a resistor (so you replace a pot with two resistors). In some cases if the pot is really turned "all the way" in one direction, you would replace with a single resistor.
<
<
< = resistor


Here's an example of a pot "turned all the way"

| ------------ upper lug wire
| ------------ wiper wire
<
<
<
| ------------- lower lug wire
|

You probably want to check this article out.

http://geofex.com/Article_Folders/potsecrets/potscret.htm

[mcasey1]

I guess Im really just looking at a jumper here, because I suppose when the pot is turned all the way clockwise, the resistance is 0.  This is measured from the wiper to the lower lug.  Is this correct?

[tcobretti]

I believe that if you just want it dimed you'll take the pot out and wire a 2k resistor and the 22u cap from the emitter of Q2 to gnd.

[petemoore]

  Take the pot and a dmm...
  attach leads to wiper and an outside *lug...
  measureing...as the shaft is turned 'toward' *that outside lug [assign one for the first 1/2 of this test] the resistance decreases to 0 [if the pots working].
  Second half is to disconnect the outside lug and connect the other outside lug and repeat test with DMM...turning the knob...taking readings and seeing what's happening...maybe even seeing the 'ratio' of a log vs linear pot...by taking notes of R values on both sides with the pot at 0, 1, 5, 9...and 10 settings of the indicator knob on the shaft.
  With a linear 100k pot you should get 50k/50k between the wiper and each outside lug...the 90k/10k or something close when in set to '1' or '9'...an audio pot won't be symmetrical like this...read GEO secret life of pots..