Fuzz Face and Impedance

[vanessa]

I recently had a post were I had an issue with the Axis Fuzz Face V3 si. It turned out that the PN2369 was causing noise when the volume was off on the guitar. I solved the issue by putting a resistor in series with the circuit. It was a low value 8.2k but just enough to stop the noise and still preserve the FF’s tone.

I have read that putting a resistor in series with this circuit will get you back your wah sweep as inherently there is an impedance mismatch between the two circuits.

Has anyone had any success doing this and what is a good value to get the wah sweep back but still keep the fuzz face tone intact?

[vanessa]

Bump...

:cry:

[Coriolis]

Eh...wah sweep in a Fuzz Face?  I'm a little confused as to what circuit you are referring to, will have to check at Fuzz Central. :?:

C

[nightingale]

Vanessa,
I get what you are saying. I think a true FF purist would say that to preserve the tone of the FF it must be connected directly to your guitar, with no series resistance on the input. There have been several discussions about the unique sound quality that comes from your guitar pups being loaded down by the impedance of the FF. [at least i think that is how it goes].

RG Keen touched on the series resistance in his technology of the FF article. It is a good one for sure! everytime i re-read it.. i get a fresh urge to mess around with the FF circuit again.

I personally like series resistance in my FF pedals. I use alot off wah wah drenched in echo, so I have gone the Gagan pre-gain route. This is a guitar pot wired in series to the front of the FF circuit. It pretty much acts as an extra guitar volume pot wired to the front of the FF circuit. It can be seen on some of the Easy Face variants. This helps the FF and the Wha get  along just fine.  I have never noted the the perfect amount of resistance to   avoid the wha problems you speak of.

This is sort of off topic, but i prefer a little extra series resistance on my BMP type builds. Instread of the normal 33k. I usually swap that for a value somewhere around 150k or so. This way i get more usefull fuzz at the lowest fuzz settings.

hope this helps,

[markusw]

I don't know whether a R is sufficient, but a buffer at the output (e.g JFET) should do it, if you mean you've got an issue with the fuzz after the wah. Please correct me if I'm wrong.

Markus

[vanessa]

I don't know whether a R is sufficient, but a buffer at the output (e.g JFET) should do it, if you mean you've got an issue with the fuzz after the wah. Please correct me if I'm wrong.

Markus

I guess I should clarify myself a bit.

Wah-wah into Fuzz Face has an impedance mismatch.

I've looked into the JFET buffer at the output of the wah-wah (that's where your suggesting to put it?). I have read that this affects the fuzz face's tone greater than putting a resistor in series with them. Is this BS?

No magic resistor value???




:cry:

[trjones1]

I don't know about putting a resistor in series with the fuzz, but I just added a jfet output buffer onto my wah and I would highly recommend it.  I didn't notice any great difference in the fuzz tone (other than what the wah is already doing) and the buffer gives you the option of boosting the wah output a little.  I was wah-wahing all night.

[Doug_H]

Put a buffer and a 47k series resistor on the output of your wah. That should do it.

Doug

[Seljer]

I just made a fuzz face 3 days ago and just now I discovered this problem. Luckily, the mods from the Geofex site mention a 50k trimpot for input volume thatI had allready made it with and I can fix things up. Its something like 10k for no whine from having the guitar volume on 0 and somewhere around 33k for having no whine from the wah wah.

[formerMember1]

wait isnt that what the Bias pot on the Fulltone 69 fuzz is for....

Now isn't that the same as the Smooth pot on the Axis Face SiliRev3?

Isn't the above all series resistance like Vanessa mentions she wants?

[brian wenz]

Hello Hello --
 formerMember1-- Yeah, any of those "pre-gain" pots are variable res. in front of the circuit.........which is what I was talking about in the original thread. I've found that by putting a fixed resistor [1K, 10K, whatever...] at the front of a Fuzz Face type circuit the gain is slightly decreased and noise may actually be increased.   Come to think of it, everytime I put a pot at the front of a FF the noise is increased a bit, too.
Brian.

[formerMember1]

wow i never knew that thanks man

[brian wenz]

Hello Hello--
   The thing is, I wish that I could find out some hard-and-fast-rule about the real reason for the extra noise.........maybe there is something else going on that is actually more of "the real reason" for the hiss.  
Brian.

[aron]

Perhaps try a metal film, fixed resistor and see what happens?

[Doug_H]

Don't mod the fuzz face input- mod the wah output.

Doug

[Johnny Guitar]

Is the Axis FF pos or neg ground?

[brian wenz]

Hello Hello--
   The Axis Fuzz Face is NPN [neg. ground.]
Brian.