What causes the squealing noises when running a wah into a fuzz face?

[VintageCharlie]

Hi guys,

i'm about to turn my american made v847 into a McCoy/v846 - i want it to be as authentic as possible to the originals - so it will be the same circuit without mods and practically all nos parts (nos parts mainly because i like how they look, not because i believe they would do magic to the circuit), including piher resistors, tropical fish, etc. ( My only concern is this - i want to be able to use it in front of my fuzz face (a JHF1 or whatever it is called - the newer blue/greenish one that sounds ok stock, but that will also get a nos treatment, including some lower gain silicon or maybe some Ge transistors) - and as i tried putting the wah in front of it, i got the terrible squeals all over the wah range. It was unuseable this way. I've read it's a common problem when pairing these two pedals and IIRC it was due to the impedance of the Fuzz Face (don't recall if it's considered high or low). I would like to avoid buffers or boost pedals between the two, as i'd prefer to do it as simple as in the old days. My question is - why doesn't this seem to be aproblem to Hendrix, for example? Wah in front of fuzz - no squeals, or at least rather seldom and controlled. Between my v847 and the JH fuzz i had so much squealing that there is no way how they can be controlled or avoided by playing style, etc. - they are so bad that they render this combination unuseable.
So it would be great if you guys could explain what is the cause for this squeal galore and if there's any way to avoid it when re(building) both of these pedals, without resorting back to a buffer of any kind? Might it have to do with the extremely high hfe in the v847 trannies? Would it be enough to simply build stock circuits like they were done in the 60's, including the rather low hfe transistors to avoid these problems? Or would i have to be prepared to mod some component values?
(Sorry if this topic has been beaten to death, but i had no luck with the search function.)

Thanks a lot in advance!

Cheers!

Karlis

[VintageCharlie]

p.s. the other problem i've read about wah+ff is that the wah sweep gets really narrow if it runs before the ff. Besides a buffer or some other pooster or pedal between the two, is there anything that can be done to widen the sweep. Might this also be related to the high hfe's of the reissue pedals or was it also a problem in the old ones?

[John Lyons]

Impedance mismatch. Put a 100k resistors in series with the output of the wah or the input the the FF.
Or build the Foxroxx wah fuzz enabler (buffer).

[VintageCharlie]

Thanks John!

Would the 100k resistor solve also the narrowed sweep of the wah or just the squealing?
Or would i need the (foxroxx type or other) buffer to get back the whole sweep of the wah?

Thanks!

[Derringer]

good info on a wah output buffer here
http://www.muzique.com/news/wah-pedal-buffer/


My question though ...
A FF type circuit wants to see a signal with guitar-pickups-like impedance right?
So in the above link, isn't it going to see a much lower impedance?

Like you pointed out john regarding the addition of resistance to the output signal, wouldn't it be better to use an output buffer like that but have something like a 10K - 33K resistor coming off of the emitter in series with the output cap?

[VintageCharlie]

Thanks Derringer!

So is there some sort of a consensus on the best buffer design for this purpose? The foxroxx buffer that is being mentioned all over the net or maybe this one: http://fuzzcentral.ssguitar.com/mccoy.php or maybe the one that Derringer gave a link to, or are they all basically the same? (If there is really no way around it altogether). I might settle with adding the resistor to the output of the wah or input of the ff, if that can solve at least the squealing and decide on the buffer later on - if i can't get enough sweep from the wah + ff combination. Though in the old 60's recordings it seems like the wah sweep indeed is rather narrow when used with the ff and i might find it ok like that too.

[petemoore]

  Depends on what you want the buffer to do.
  That stated...
  All the really bad buffers got tagged and nobody uses 'em anymore.
  That leaves...AMZ and various buffers for various purposes.
  I don't drive 30' lines so any...depending on the power supply...and what 'pump' [transistor] I happen to want to get or already have.
  Or opamp...
  It's like car jack, jack car and tire change, don't worry about which jack did it, and drive.
  Since there's no 'magnifying' or multiplying of signal potentials [like a gain stage] and all the 'art' [how well the buffer output copies the buffer input] is easier for the transistor and transistor bias-er to make symmetrical/near identical 1:1 transfer of gain.
  Of course if there's a buncha holes leakin' like there always seems to likely be, and the buffer maintains pressure enough to make the leaks insignifigant, before/after buffer testing will probably show better signal transfer 1:1 instead of one divided by whatever...so bright highs or increased amplitude may make it sound like a voltage boost since the equipment recieving the signal has more 'intact' potential swings to work with.

[zombiwoof]

The interaction between the wah and fuzz WAS a problem for Hendrix, at least in the early days.  He tried using the wah before and after the fuzz, there are times in the live cuts where you can hear the same squealing effect, Jimi just used it to his advantage in making certain noises.  I'm sure that Roger Mayer did mods to his FF and wah later to help with the problem, although it is unclear exactly what he did. Also, it has been suggested that his placement of the Univibe may have helped deal with the problem, although I don't know if this is true or not.  The output buffer added to the wah is the common fix for the problem, though some people don't think it is the ideal solution.  Why wouldn't you want to try it?.

Al

[jasperoosthoek]

The narrow wah range thing is a natural consequence of the wah circuit interacting the the low impedance FF.

Indeed, Jimi used the 'narrow wah range' sound to his advantage. I would even go as far as saying it was one of his signature sounds!

Voodoo Child is a good example. Except for the intro there are no 'normal' wah sounds. It's all done by switching the wah on and off. Maybe as much as 50 times or more in the song. The solo after the first verse is a good example of his narrow  wah/FF sound. At the end of that solo he goes wild with the wah switching while he repeats a lick. The perceived 'w' of that wah sound is actually the FF only. At the end of the solo he bends a 17th fret of the E string. While he bends he turns it on again. It's kind of hard to hear on the original, but I have bootleg studio recording of the original song where you even hear a click of the switch .

I don't know why his wah doesn't always squeel. I have mine setup exactly like that and doesn't squeel at all, never did. Maybe because I use a good split power supply. No daisy chains.

Anyway, if you want the real classic sound then get rid of the squeeling by setting it up properly. An output buffer will solve the squeeling but will be very far from the original sound.

[VintageCharlie]

Well, there are 2 main reasons why i would like to avoid the buffer, if possible - 1. i'm after authentic builds for both pedals and a boffer wouldn't fit good in this paradigm 2. i'm a fan of a lot of Jimi's stuff and like to do covers of his music, hence i also try to mimic a lot of nuances from his gear. And the narrow sweep of the wah, as i mentioned earlier, probably might be a thing that i actually like, as this is what i hear on the recordings too.
My only real concern is the squealing. Of course you hear that in the recordings, but occasionally and controlled - he knew when to get that and used it for the psychadelic soundscapes he created wit feedback, etc. I guess the squealing in his units appeared when he didn't move the wah for a short while. But between the v847 and the ff the squealing was there all the time - it was unuseable. I HOPE that when i mod both to proper vintage spec, including low hfe transistors, that the squealing might be minimized already. I'm just looking for some advice for the case it still might be as bad as now.
Well, maybe Jimi was such a master that he used the wah in very restrictive ways to avoid the squeal when it was not desired, but in my case i couldn't even find a restricted range that would work ok, even while moving the dam thing...

Thanks for all the advice guys!

For the moment i hope i can manage it without the buffer. But it might be that the output or input resistor mod will be needed. And here i'm a bit confused now, as John recommended a 100k resistor, but Derringer asked if a 10k-33k wouldn't be better.

I have little to no understanding of electronics - i'm a "monkey see, monkey do" - just copying the original circuits. (the solderiung will be done by a friend who won't fry anything or make 1/2 of the joints cold, as i would with my current (dis)abilities

[jasperoosthoek]

Are you telling be you have a silicon FF?!! If so, get some proper selected Ge transistors from www.smallbearelec.com and report back . 12 buck well spent...

I built a Si FF last year and it squeels like hell with my wah. My Ge FF doesn't squeel if set up properly and I can replicate those Jimi sounds without a problem. My chops still need work though !

Jelly 292 is another good example of that sound. Love it . Also Midnight from South Saturn Delta (plus Univibe).

[VintageCharlie]

Yes, it's a silicon ff at the moment and i suspect the trannies in that are high in hfe even for silicon - as with all reissues...
I have some NOS transistors, including some real NKT ones, but they are not the 275 marked ones. A guy from another forum helped me out and measured a bunch of them for hfe around 100. Afaik the one at 70 hfe was no problem, but i'm not sure if he managed to find something in the 100-120 hfe range exactly, as these were of a rather low hfe range. I think NKT214 or somnething like that. I haven't tested them myself to see if they really have the proper ranges - getting some extras from small bear might be a good idea, just in case...

But didn't Jimi later use the silicon FF? Also with the wah. Seems to have worked for him. But he also worked like an animal with all that rather finicky gear to get those tones under control.

[Derringer]

For the moment i hope i can manage it without the buffer. But it might be that the output or input resistor mod will be needed. And here i'm a bit confused now, as John recommended a 100k resistor, but Derringer asked if a 10k-33k wouldn't be better.

sorry, what I meant was to have 10K - 33K after a buffer to simulate a higher impedance

but without a buffer, you could always try just putting a 100K linear pot wired as a variable resistor between the wah's output and the FF's input and dial in how ever much resistance you need to get the sound and interaction you want

[VintageCharlie]

ok, sorry for the confusion!
Thanks for the info!
So a 100k trimpot would do the trick too? Or a slightly larger one? This would be best as i could experiment without the need to solder/desolder, etc.

[Derringer]

yeah

it might be all that you need

do you have a breadboard?

[VintageCharlie]

Nope, but the friend who will do the job has one for sure.

And as for the buffer - i might as well just build a simple clean booster of some sort and put it inbetween the wah and fuzz in case i want more sweep? If i understood it correctly, there wouldn't be any difference if it's on-board on the wah or a seperate unit?

Thanks for all the fast replies and help guys!

[Derringer]

a booster never hurts any rig 

but if you build it with true-bypass, then when you have the booster off you'll be back to square one with the wah going direct into the fuzz face

Some folks like putting a variable resistor (50K usually) on the front end of their fuzz faces anyway. Fulltone did it.
When you increase the resistance there and play with the regular fuzz knob you'll get some slightly different shades of fuzz.
Putting some resistance on the input of the FF would be the same as putting some on the output of your wah.

[zombiwoof]

Well, there are 2 main reasons why i would like to avoid the buffer, if possible - 1. i'm after authentic builds for both pedals and a boffer wouldn't fit good in this paradigm 2. i'm a fan of a lot of Jimi's stuff and like to do covers of his music, hence i also try to mimic a lot of nuances from his gear. And the narrow sweep of the wah, as i mentioned earlier, probably might be a thing that i actually like, as this is what i hear on the recordings too.
My only real concern is the squealing. Of course you hear that in the recordings, but occasionally and controlled - he knew when to get that and used it for the psychadelic soundscapes he created wit feedback, etc. I guess the squealing in his units appeared when he didn't move the wah for a short while. But between the v847 and the ff the squealing was there all the time - it was unuseable. I HOPE that when i mod both to proper vintage spec, including low hfe transistors, that the squealing might be minimized already. I'm just looking for some advice for the case it still might be as bad as now.
Well, maybe Jimi was such a master that he used the wah in very restrictive ways to avoid the squeal when it was not desired, but in my case i couldn't even find a restricted range that would work ok, even while moving the dam thing...

Thanks for all the advice guys!

For the moment i hope i can manage it without the buffer. But it might be that the output or input resistor mod will be needed. And here i'm a bit confused now, as John recommended a 100k resistor, but Derringer asked if a 10k-33k wouldn't be better.

I have little to no understanding of electronics - i'm a "monkey see, monkey do" - just copying the original circuits. (the solderiung will be done by a friend who won't fry anything or make 1/2 of the joints cold, as i would with my current (dis)abilities

I think you're missing one point, Jimi's pedals had the same problems as you are experiencing, until they were modded by Roger Mayer.  So, his pedals weren't stock after Mayer started working with him.  The problem of the wah not interacting with some fuzzes is inherent in the original design of those pedals, so getting your wah to original specs is not going to fix the problem.  Yes, you can interject a pedal in between the wah and fuzz that will help with the squealing when all three are on, but that in-between pedal either has to be true bypass and off when you are using the fuzz by itself, or of the perfect impedance to work in front of the FF when it's on.  The advantage to the output buffer on the wah is that it is only activated when the wah effect is activated, when the wah is bypassed so is the buffer.  So, if you want your FF and wah to be stock original circuits, you are going to have to live with the inherent problems of those circuits.  I have had a little success with certain compressor pedals inserted between the wah and fuzz, that seem to be just the right impedance to work with either or both, but it takes some experimentation to find the right pedal.  And the FF variable input thing works for some people, but it will probably change the sound of the FF a little.  There are little trade-offs to all of the options, you just have to find one that works for you.

Al

[VintageCharlie]

Thanks for the heads up!
You're right, i shouldn't get caught up on one particular solution. I guess i'll have to experiment with the options that are available. I'll probably start with the most primitive and easy ones.

[jasperoosthoek]

But didn't Jimi later use the silicon FF? Also with the wah. Seems to have worked for him. But he also worked like an animal with all that rather finicky gear to get those tones under control.

I didn't know he used silicon transistors in the FF circuit. But I do know he used the Roger Mayer Axis Fuzz which has silicon transistors.

And as for the buffer - i might as well just build a simple clean booster of some sort and put it inbetween the wah and fuzz in case i want more sweep? If i understood it correctly, there wouldn't be any difference if it's on-board on the wah or a seperate unit?

Like zombiwoof said, if you want to have a clean booster between the fuzz and wah then you have to integrate it in the wah. A permanent unit in front of the FF it will change how the FF sounds. The characteristic sound is caused by the interaction of the guitar's pickups and the FF. That will be lost if you permanently use a buffer. Or you would have to turn it off together with the wah. Then you might as well integrate it in the wah.

I personally like how it interacts with the wah. I wouldn't want to change that. The fuzz is too muffled sounding to work with a wah propery. If I want good interaction fuzz and wah I use the Colorsound Tonebender (like Tony Joe White).