Why is the Fuzz Face circuit so unfriendly to other pedals?

[Ben Lyman]

Can it be adapted to better work with something else? Would a simple buffer make it work better with a Wah Wah or Tubescreamer in front of it?

[karbomusic]

Because it loads down the guitar, and for many that is part of the heart of the magic. Place anything in front, lose the loading and the magic. There are some circuits to help emulate it but I went the route of not placing anything in front because I want that sound and my attempts to get around the physics via emulation just didn't work for me. YMMV of course.

[Ben Lyman]

OK, I agree, everything I try seems to make it lose "The Magic". Does "loading down" mean the guitar pickup is working harder because the FF has a high or low impedance?
Fulltone claims the Clyde will work before a FF because of the buffer he puts in it. I tried it with my buffer and then with some Boss pedals but nothing seemed to work.
I tried my crybaby wah AFTER the FF and that did not sound good, though I thought I read of people doing it that way. So, anyone here use a wah wah after their FF?
When I tried it, the FF took over and the wah had very little to almost no effect on the tone.

[idy]

Low impedence loads the source, it lets too much current through, more current than you pickups can produce. High, like one million ohms, lets hardly any current through. Kind of funny that a lot of resistance (impedence really) is a small load and a little bit is a big load. Something that loads more "draws" more current.

The tone shaping part of the traditional way is right there at the very end of the circuit with nothing to protect it from interacting with a low impedence down stream.

I experimented enough with the Wah/FF to find the Foxrox Wah buffer that is  small and does the trick. You could put it in which ever box it fits.
Check Sabrotone or just google it.

[Keppy]

http://www.muzique.com/lab/pickups.htm

This describes how to add circuitry to the input of an effect to give the input signal the characteristics of a signal that comes straight from the guitar. Nothing's perfect, but that seems like more or less what you're after. Think of it as an anti-buffer.

Note that if you plug an actual guitar into the pickup sim, it will load it strangely. If you use this, you should either make it switchable, or put a buffer before the anti-buffer, as weird as that sounds.

[Gus]

A search should find a number of theads about this.

[GibsonGM]

Low impedence loads the source, it lets too much current through, more current than you pickups can produce. High, like one million ohms, lets hardly any current through. Kind of funny that a lot of resistance (impedence really) is a small load and a little bit is a big load. Something that loads more "draws" more current.

The tone shaping part of the traditional way is right there at the very end of the circuit with nothing to protect it from interacting with a low impedence down stream.

I experimented enough with the Wah/FF to find the Foxrox Wah buffer that is  small and does the trick. You could put it in which ever box it fits.
Check Sabrotone or just google it.

This is very very close to what happens.   The input IMPEDANCE (AC and DC resistance) of the typical FF is very low...yes, this loads the source...the FF tries to draw current from the source ,the guitar falls a bit short, and hence you get the "magic" of the FF.  It needs the guitar's output impedance to make the mojo, in layman's terms. 

This magic mojo comes, in part, from the fact that because of the capacitances present at the input of the circuit (both intentional and parasitic, as from the Miller effect and the guitar cord...),work with that low input impedance, and you begin to lose high frequencies first...the capacitances pass the high frequencies to ground as caps have a lower REACTANCE (AC resistance), which creates a filtering effect.   You see the effects of this when you turn the guitar V knob down, adding resistance to the 'filter' ("cleans up nice").

Unfortunately, these same mojo-making properties don't play well with the output impedances of other effects, and can result in the loss of that mojo by 'upsetting' the balance of tone-shaping that's in play with your typical FF.   As mentioned, there are 'fixes', but it seems that most of them change the tone you wanted in the first place.

And yup, this topic is well-discussed!