Wah Output Buffer

[soupbone]

So,I finally found a wiring diagram for this old Dunlop crybaby I've been trying to get going.Got it working finally!My next thought is should I add an output buffer,or no?

[GibsonGM]

I wouldn't bother, personally. Your output Z should be fine for the next stage.

[Seljer]

The output buffer really only changes things when you're placing it in front of a pedals thats very sensitive to impedance (i.e. the relatively low impedance input of a fuzz face, where running wah->fuzz creates crazy oscillations)

[DougH]

http://www.aronnelson.com/gallery/main.php/v/DougH/OddsNEnds/crybaby_sch.gif.html

The output series resistor helps it work in front of a low Z fuzz more than anything.

[joegagan]

my newest thinking on this, especially after checking the result in LT spice is that an output buffer is needed when there are gain/ volume trimmers or pots in the wah to add low end or gain. on my sweep-widened circs and some others, by the time i get a wah signal with a low end that i like, the volume exceeds the bypassed sound. adding a simple out volume changes bias and robs the low end that i worked so hard to achieve.
a simple out buffer allows use of an out vol that is isolated from the circ sufficient to preserve low and with no other ill effects i have found.

[joegagan]

the dunlop bonamassa sig wah has an out buffer.

[GibsonGM]

http://www.aronnelson.com/gallery/main.php/v/DougH/OddsNEnds/crybaby_sch.gif.html

The output series resistor helps it work in front of a low Z fuzz more than anything.

Since it's a FF problem, I consider the series resistor to be a FF INPUT component!! LOL   
Really, we MUST stop blaming the wah!  )

Does the Dunlop sig wah have a high output Z, Joe???

[joegagan]

[/quote]


Does the Dunlop sig wah have a high output Z, Joe???
[/quote]

i sold the one i had, did not measure, but i can PM you the schem, a buddy of mine in WIS did a sweet hand drawn one.

[GibsonGM]

Cool...if you've got one, I'd take a look, if for nothing more than curiosity (as in, why is there an output buffer?).  Not generally needed, but sometimes something ahead of it may make it a necessary thing, I guess.

[DougH]

http://www.aronnelson.com/gallery/main.php/v/DougH/OddsNEnds/crybaby_sch.gif.html

The output series resistor helps it work in front of a low Z fuzz more than anything.

Since it's a FF problem, I consider the series resistor to be a FF INPUT component!! LOL   
Really, we MUST stop blaming the wah!  )

Yes, that's really true. For a hi Z input (say, 500k-1M), 47k is fairly negligible. But for the lo Z FF input it really makes a difference.

[joegagan]

i have a theory about the bonamassa, but i could be wrong.
they are using a fancy-dancy pot from Tt industries. 2 million cycle job. the log taper that TT offers is still quite wide with the standard size gear, they are actually sweeping it from 40k to 100k.  i believe they tuned the circuit to mesh with this  R range ie; similar to the old colorsound / foxx / musonics that used only 50 to 60 % of the R range ( similar 40k to 100k range) they tune the whole filter so low that the 0 ohm to 40k are really low. without an output buffer the highs would suffer in this arrangement. it's all just a theory. they might just do it because JB thinks he needs one to go into a fuzz.

( edit - i should clarify that the theory part only applies to the conjecture about why dunlop put a buffer there. the other part about the treble being preserved with an output buffer has been proven by me in spice and real world experiments.)

there are a few other tricks from the colorsound in the JB wah, which is funny because they stress the 'vox-ness' of the inspiration in the marketing.

[zombiwoof]

I would add that the buffer in the Bonamassa wah is switchable on/off, so you can have the original non-buffered output if desired.  Bonamassa says he prefers this setting.  I assume he must use the wah after the Fuzz Face, as the non-buffered output of the wah would make the wah into FF have oscillation problems, as is a common problem with wahs and vintage fuzzes.

Al

i have a theory about the bonamassa, but i could be wrong.
they are using a fancy-dancy pot from Tt industries. 2 million cycle job. the log taper that TT offers is still quite wide with the standard size gear, they are actually sweeping it from 40k to 100k.  i believe they tuned the circuit to mesh with this  R range ie; similar to the old colorsound / foxx / musonics that used only 50 to 60 % of the R range ( similar 40k to 100k range) they tune the whole filter so low that the 0 ohm to 40k are really low. without an output buffer the highs would suffer in this arrangement. it's all just a theory. they might just do it because JB thinks he needs one to go into a fuzz.

( edit - i should clarify that the theory part only applies to the conjecture about why dunlop put a buffer there. the other part about the treble being preserved with an output buffer has been proven by me in spice and real world experiments.)

there are a few other tricks from the colorsound in the JB wah, which is funny because they stress the 'vox-ness' of the inspiration in the marketing.

[joegagan]

there is a switch- it can go between true bypass and 'drag down' mode like old non tbp wahs- but stangely, the way they did it, the signal goes thru buffer in front of wah at all times. i think tripps said it was to get the treble rolloff effect when wah is switched out ( but it isn't doing the same thing as a vintage wah with the buffer there).

the input buffer is typical dunlop input buffer, but smd under the board.

there are two buffers in the jb - input and output, both on and in circ at all times.

[pinkjimiphoton]

fwiw, i found a "passive" buffer using a 50k pot in series with the output of the wahboard itself (i put mine on a switch) works better than every buffer that's been posted
on the net. the best one is probably the foxrox one, for anything but wah use.

a small resistance will help if you need a buffer. all the ones i've tried (i built every wah buffer i could find on the dang net, and people delude themselves thinking it will help with
fuzz interaction.

my brother mike is a guy who uses the wah buffer and silicon fuzzfaces and he sounds good, but i played his rig, and it's not even close to the same response.

i personally don't care for the oscillation between wah and fuzz at all, and buffers just make it worse on every one i've tried. note: this is only putting a wah before a true fuzz in the signal chain.
if using silicon  distortion devices, or if the fuzz comes after the wah, a buffer is like any other circumstance... if you feel the signal needs it, it's all good.

but if you're asking cuz ya want it to play nice with fuzz... try the resistance trick. a fixed resistor is even fine if you don't wanna use a pot.

if you're not a germanium addict, you can put wah before fuzz, but you won't like it i don't think. overdrives and distortions and stuff sound better after.

[joegagan]

jimi, your experience gives good insight. you have a highly developed tone which you have spent decades defining and refining.

but i find that my experience is opposite much of what you have said above - which brings us back to the old adage

"try for yourself in your particular setup".

[MrStab]

i'm not much of a fuzz guy myself, so any output buffers i've put in my wah have purely been out of having nothing better to do,  but i've read about this issue from time to time, and Jimi's more-effective solution, and wondered: wouldn't the same "cure" for active pickups into fuzzes be the ideal solution, as in a simulated pickup via. a transformer? e.g http://www.muzique.com/lab/pickups.htm. i built a fuzz for someone once, and was unsure if they had passive or active pickups so i did a bit of reading for either eventuality, and i got the impression that an output buffer is probably the last thing you want. but then people like Joe have had differing results, so who knows.

i've not done much reading exclusively about this, so apologies if this has already been debunked a million times

[pinkjimiphoton]

jimi, your experience gives good insight. you have a highly developed tone which you have spent decades defining and refining.

but i find that my experience is opposite much of what you have said above - which brings us back to the old adage

"try for yourself in your particular setup".

+1 bro. just dispensing the caveat that just cuz net wisdom says something is good, doesn't mean it is in reality. i (like you) have spent as you said decades chasing
the dragon. a lot of that for me was (still is) false leads down blind alleys.

i will say this.. the 50k pot trick was/still is the only way i can get my fuzzface(s) to play right without having the fuzz first. it ain't right... but it gets pretty close.
the foxrox one was closer, but still messed with the guitar/fuzz interaction wayyyyyy too much, particularly when the guitar rolled back some.
fuzzes are often kinda muddy when the guitar is cranked, but when ya turn down they tend to boost treble more, as does the buffered signal (for different reasons... the buffer is preserving guitar tone, the fuzz is augmenting it).... too much treble can sound gawdawful and have ya reaching for tone knobs that just don't quite cut it. i don't want my basic tonal range to change unless i want it to, not talking levels of distortion or other effects , but the general frequency response of the guitar. when i kick on some dirt, i want it to sound like my guitar, but with dirt.
but i tend towards different kinds of sounds than most seem to prefer.
with solid state fuzzes, it's a different story... they often need buffering to really process the guitar and sound good. 

and even then there's drawbacks, like with anything.

the one thing i WILL say for the buffered wah first is at some settings, you will get a tuneable oscillation you can sweep with your foot.. it's almost like playing two instruments at once,
and i can see why hendrix eventually preferred it for his style.... those oscillations can sound surprsingly like a second guitar sometimes.


but i agree with the esteemed mr. gagan, try for yourself. but by all means, do it with fresh ears, and gear you're familiar with enough where you can spot more subtle things.

don't just say, oh wow, this new YATS is SOOOOOO much more awesome than the last YATS cuz one value on one part was changed, and not for tone, either.

i don't care what manufacturers say.... i read this hyped up baloney even from guys that used to be like us.... class a fuzzbox from mr. wampcat comes to mind.
i realize he's trying to make a point to people who don't know effects, but he's adding to the misinfo out there. the lexicon of guitardom is whack enough already.

i mean... "sounds like a cranked class a (ummm... more like high a/b) vox ac30" is one thing... saying it's a class a circuit? ummm...

seriously, try stuff... all of it... but don't get sucked into hearing something that may not be there just cuz the "gurus" tell you it's there. including myself, tho i am far from a guru.

sorry to derail the thread so bad..
bowing out... peace to all!

[pinkjimiphoton]

i'm not much of a fuzz guy myself, so any output buffers i've put in my wah have purely been out of having nothing better to do,  but i've read about this issue from time to time, and Jimi's more-effective solution, and wondered: wouldn't the same "cure" for active pickups into fuzzes be the ideal solution, as in a simulated pickup via. a transformer? e.g http://www.muzique.com/lab/pickups.htm. i built a fuzz for someone once, and was unsure if they had passive or active pickups so i did a bit of reading for either eventuality, and i got the impression that an output buffer is probably the last thing you want. but then people like Joe have had differing results, so who knows.

i've not done much reading exclusively about this, so apologies if this has already been debunked a million times

grant, the only way to tell is to try it. some people swear by them. others can't stand 'em. i'm in the latter school.

i too added them / subtracted them just to see what they'd do.  i'd bet if i gave you three of my crybabys... one buffered, one unbuffered, and one with the 50k pot most people couldn't tell the difference. put a germanium fuzz before and after, and i bet they COULD tell the difference.

put the fuzz in front of each, and (as they're mine and all tuned to my ear) and you probably couldn't tell.

put the wah first, only one of 'em is gonna reallys sound good. see... that's the problem. if it's not gonna make it sound better, why do it?

it's an impedance issue. i am no EE by far, but if memory serves, any time you put a resistance in series with audio, and take the output off the resistance, you've changed the voltage to a current which seems easier to handle for the next thing in line.

fwiw, if i ever make it down to new mexico, or he ever makes it here to connecticut, i hope to spend a little time with joe playin pedals drinkin' beers and talkin' gear a while.

he's one of the few guys who can make silicon sound RIGHT.

ok. NOW i'm outta here!! lol

[MrStab]

it's an impedance issue

it's your very pot/resistance method that made me think to apply the active pickup remedy here - i just thought surely the two issues must be related. but now i think about it, even if pickup simulation did turn out to be the ultimate solution, it'd probably be overkill if your method is tried & tested.

i've been considering an octave fuzz lately, so maybe i'll enter Fuzzville in the not-too-distant future...

[soupbone]

Good stuff guys!I think i will add an output buffer to mine using fuzz central's layout;http://fuzzcentral.ssguitar.com/mccoy.php It has a 100k trimpot for the "volume drop" after making it true bypass.I could "adjust" the volume drop by changing the 68kr by making it 47k,but this one is an original 1st issue dunlop crybaby.The only thing i wanted to do is make it true pass with a carling dpdt switch.Plus,i'm probably gonna build me a fuzz soon.