BUFFERING A FUZZ FACE INPUT - QUESTION

[Ricardo Antunes]

Hy all
I'm just finishing to build a basic Fuzz Face (intend to do Fuller mods + Roger Mayer mods), but I've got a little problem: I can't put my Vox847 before FF, only after that cause in that way there's not "WAH", just a distorted shhh  shhhh. . I sometimes could be using this FX configuration (FF+Wah) but not always. Is the solution to put a buffer in the FF input?
What's the way to do this? The buffering solution can be used for all  effect's input? I'm trying to find some related article at Geo, but I didn't.

[phillip]

The two options are to either buffer the output of the wah pedal, or buffer the input of the FuzzFace.  To see how to buffer the output of the wah pedal, check out the Wah-Wah PDF file at Tonepad, which shows an output buffer on the schematic:

http://www.tonepad.com/project.asp?id=29

To add an input buffer on the front of a FuzzFace, check out the "Basic Buffers" article at AMZ.  I've used the buffer pictured fourth from the top with a JFET (I used the 2N5457) and two parallel resistors on the gate.  In the pedals that I've used that buffer in, I've upped the value of those two 1M resistors to 2M2 for an input impedance of 1M:

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

Hope this helps some!
Phillip

[gtrmac]

I'm considering ading a buffer to the output of my Vox Wah to solve this problem. General Guitar Gadgets has a ready to solder PCB available that could be used for instance.

[nightingale]

hello~
a very easy solution, nothing against buffers,i use one...(long cables) but a stage tuner, or some effects(with buffers)... like a microvibe/univibe between the wah and FF will do the trick... e.g., my arion stage tuner betwen my FF and wah does the job nicely... i stole the trick from hendrix!
hth,
~ryanS

[Peter Snowberg]

From my understanding, the behavior of the FuzzFace is quite dependant on the impedance presented to the input. If you buffer your pickups, you will present the circuit with something less than ideal. I think R.G. has an article about using a small transformer coil after the buffer to present typical pickup impedance to the circuit. I have seen this done elsewhere too, but I can't remember where now.

-Peter

[Craig V]

ke a microvibe/univibe between the wah and FF will do the trick... e.g., my arion stage tuner betwen my FF and wah does the job nicely... i stole the trick from hendrix!

Were tuners around back then?  I don't think he used a univibe before the wah either.  I've always heard he had a pot installed in his wahs and FF's.

[nightingale]

craig~
http://guitargeek.com/rigview/354/
i meant the uniV not the tuner... i was just going off of this diagram...
if you've never seen this site, it's a fun one!
best,
~ryanS

[Craig V]

That is quite a site!

I think the layout is confusing one of us - to me, it seems the order goes Guitar>Vox>Octavia>FF>Univibe>amp.  Would that order provide any seperation of the wah and fuzz?  Maybe I'm reading it wrong.

[bwanasonic]

hello~
a very easy solution, nothing against buffers,i use one...(long cables) but a stage tuner, or some effects(with buffers)... like a microvibe/univibe between the wah and FF will do the trick... e.g., my arion stage tuner betwen my FF and wah does the job nicely... i stole the trick from hendrix!
hth,
~ryanS

My DOD 201 does this trick, but the problem is the effect is not true-bypass and mucks with the clean tone when off. I could wire it with a DPDT, but then I'd lose the buffer effect. I'm thinking of putting the wah and phasor into a bypass loop pedal.

Kerry M

[Ge_Whiz]

From my understanding, the behavior of the FuzzFace is quite dependant on the impedance presented to the input. If you buffer your pickups, you will present the circuit with something less than ideal.

When I run a buffered input into my Fuzz Face, I lose the operation of the drive control - it's just at max all the time.

[nightingale]

circles~!

[gez]

Something similar came up a few weeks back and I suggested the following solution.  It was in reply to Chris S, who later emailed me back and apparently it worked a treat.  I don't know if he changed resistor values, perhaps he'll chime in.  I've edited the post heavily to cut down on waffle:

It seems to me that what you want is a buffer with high output impedance which can in turn be loaded by the FF, something with unity gain and output resistance equivalent in value to the internal resistance of your guitar pickup.

You're probably best off with a MOSFET.  You could use a n-channel MOSFET with a 10k drain resistor (for starters) and a 10k source resistor. Connect the gate to the wiper of a 100k trimpot via a IM resistor and connect the outer lugs of the pot across the rails. Move the wiper up from earth till you read 2.5V at the source. The input cap attaches directly to the gate, the output cap comes off the drain.

The above circuit has an output resistance of 10k. This would be loaded by the low input impedance of the fuzzface and 'might' work at sorting out your problem. If loading isn’t enough, you can start increasing the value of the drain and source resistors - keep them equal value and adjust the trim pot accordingly (this is why I recommended a MOSFET - the drain current may get quite low).

[gez]

P.S. It was for an input buffer.  I think I still have the schematic I sent him if you want it.  The Fuzzface wasn't positive ground either (if I recall) so you'd need a p-channel if yours is, or slap a large value cap across the rails.

[Gus]

The 3 tran is a buffered Si ff type.   The guitar pickups and pot etc are part of the circuit of the FF(this is with the guitar to FF).   The base of the first transistor is a summing point.

 One part of the gain structure is the feedback R 100K in standard FFs divided by the mess of the guitar.  Passive pickups being inductive often 2 or more Henrys cause the guitar signal to drop at high fregs as well as the Z of the guitar goiing up.  With the Z of the guitar going up the first stage gain of the FF goes down.    Alot of the feel comes from the first stage reaction with the guitar.

 Back to the 3tran.  The first stage is EF with low ouput Z.  The 10K between the first stage and 2 nd transistor is a Crude pickup,guitar sim.  The .01uf across the 1K in the output section is a lowpas filter set at about 16Khz to take some edge off and sound alittle closer to a FF.

 The use of an inductor between stages instead of the 10K is a good Idea.  This has been posted on the web by others in the past.  Jack or R.G. or I forget.

 Gus

[Ammscray]

ke a microvibe/univibe between the wah and FF will do the trick... e.g., my arion stage tuner betwen my FF and wah does the job nicely... i stole the trick from hendrix!

Were tuners around back then?  I don't think he used a univibe before the wah either.  I've always heard he had a pot installed in his wahs and FF's.

Hendrix had the univibe in between the FF and wah as was mentioned and that's how he got his set-up to work...I discovered this by accident years ago and it works great!

 If you look at his pedals at Woodstock, they are not necessarliy connected in the same order as they are placed...

 BUT, if you have a modern univibe clone with true bypass then it will only obviously work when the univibe effect is ON, since the original was always "on" thanks to the cancel switch...

The other benefit of the univibe (and vox wah) not having true bypass is that it rolled off the highs and thickened the thin sounding stock strat p-ups, and I'm sure Jimi's sound wouldn't have been the same, or been as controllable had he had true bypass in all the pedals...besides the sound being brighter, all his feedback characteristics would be different...

[Ammscray]

ke a microvibe/univibe between the wah and FF will do the trick... e.g., my arion stage tuner betwen my FF and wah does the job nicely... i stole the trick from hendrix!

Were tuners around back then?  I don't think he used a univibe before the wah either.  I've always heard he had a pot installed in his wahs and FF's.

Hendrix had the univibe in between the FF and wah as was mentioned and that's how he got his set-up to work...I discovered this by accident years ago and it works great!

 If you look at his pedals at Woodstock, they are not necessarliy connected in the same order as they are placed...

 BUT, if you have a modern univibe clone with true bypass then it will only obviously work when the univibe effect is ON, since the original was always "on" thanks to the cancel switch...

The other benefit of the univibe (and vox wah) not having true bypass is that it rolled off the highs and thickened the thin sounding stock strat p-ups, and I'm sure Jimi's sound wouldn't have been the same, or been as controllable had he had true bypass in all the pedals...besides the sound being brighter, all his feedback characteristics would be different...

[Craig V]

Sounds like I need to try it.  It's always hard to tell how Jimi had his pedals arranged, with that usual mess of cabling.  On my Berekeley DVD, he doesn't even have the acutal Univibe on stage - just the foot controller.  

This could be a great discovery that you found.  My wah howls like crazy with my FF.

But, if I remember correctly, wasn't the Univibe first used by Jimi in August 69?  I wonder what he did before then.

[idlefaction]

in terms of tone possibilities, the ff loses it's interaction with your tone and volume controls if you buffer it's input - the answer definately lies with buffering the output of your wah.  go with the PCB you were mentioning.  

i think the ff project could do with a warning on it explaining about this cos it just seems so inexplicable to most people!  you put your wah before your ff and suddenly, no sound!