my first attempt at Crybaby Wah Modding

Started by Exactopposite, April 27, 2006, 09:43:05 PM

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Exactopposite

Awhile back i got a crybaby wah (standard gcb-95) used for $35 just to experiment with modding it. i have a colorsound reissue wah that i really dig, and while i can get some great sounds out of it, it doesn't do the classic vox wah sound. so i figured i'd get a crybaby or vox and mod it to suit that purpose.

anyway, now the time has come to get down to the mods. i'm doing all your standard mods (vocal, q, true bypass, etc) to this thing at one time to see what i come up with. i have a yellow fasel, a switch, and a fulltone pot on the way from small bear. i got the rest of the parts locally from radio shack. i'll see how it sounds first before i start trying different types of resistors and caps. since this is my first time trying to mod a wah i wasn't sure which inductor to pick so i jsut took a shot on the yellow fasel.  i saw from searching here that a lot of people like them. since i'm use to the sweep of the colorsound, i'll have to adjust to the crybaby (i never use it) , so things that will affect the sweep (like the pot) won't be a big deal for me. it's not gonna make the pedal feel different to me since i haven't been using it anyway.

i just wanted to come and share my project with the rest of the pedal geeks. when the parts get in and i finnish the modding i'll post a clip (maybe a few) of it and see where i stand.

while i'm at it i'm curious to know about replacing the transistors and which ones may be good to try. i may or may not decide to replace mine depending on how the mod goes, but i haven't seen much info on this aspect of wah modding.

(next up, true bypass mod for my vintage big muff. the bypass on that thing  SUCKS)

petemoore

   It probably has MPSA18's in it.
   Lower Gainers like 2n2222, 2n2369 [good for FF, and if you're socketting the transistors anyway...], NTE123, 2n3904, 2n5088, all sound different and can influence the frequencies of the sweep.
  BC109's or BC108's had a 'unique' [to them] grind to them in my YFaseled Etc. modded Vox Wah.
Convention creates following, following creates convention.

LyleCaldwell

What does this button do?

psionicaudio.com

Exactopposite


Noplasticrobots

I made direct recording of my wah before and after installing a buffer...holy crap, what a difference. The thing literally had breathed after installing that buffer.
I love the smell of solder in the morning.

Exactopposite

Quote from: Noplasticrobots on April 28, 2006, 02:53:07 PM
I made direct recording of my wah before and after installing a buffer...holy crap, what a difference. The thing literally had breathed after installing that buffer.

how much of a difference does it make if there is another pedal in the chain with a buffer?

Noplasticrobots

To be honest, I'm not too sure. I don't have enough cables to find out! I need to get some patches.
I love the smell of solder in the morning.

Exactopposite

i jsut did a few of the mods while i had time. i replaced the 33k resistor with a 100k (vocal mod). replaced the .01uf cap with a .022 (range mod). and i replaced the 1.5k resistor next to the .01 cap (that got changed to .022) to a 2.2k resistor to increase the mids. the switch, inductor, and pot were shipped yesterday so they weren't here for me to install.

it sounds a lot better now than before, but now the bottom half of the sweep does nothing. it gets to this bassy part and there is no change for the rest of the way back. before i did the range mod i adjsuted the pot so that it would be as far as it could go in the treble direction when the pedal was pressed all the way down, so it's not where the pot is set at. i'm hoping the fulltone pot will have better range and remedy this when it gets here.

the part of the sweep that is working sounds much better than stock, but the lower part of the frequency range is unsuable right now.

if it matters, the resistors were your garden variety radio shack stuff. the shack was out of .022 caps so i used the only one i had on hand which came out of my MIM strat when i replaced it with a different value.

Exactopposite

oh and while i'm at it. i recall seeing an article somewhere for called something like "anatomy of a wah". does anybody have the link? i cna't seem to locate it.

Paul Marossy

Quotei recall seeing an article somewhere for called something like "anatomy of a wah". does anybody have the link?

I think you mean "The Technology of Wah Pedals" at www.geofex.com ?

Exactopposite

Quote from: Paul Marossy on April 29, 2006, 12:36:00 AM
Quotei recall seeing an article somewhere for called something like "anatomy of a wah". does anybody have the link?

I think you mean "The Technology of Wah Pedals" at www.geofex.com ?

yup that's it. i guess that's why i couldn't find it. lol

thanks

Toney

Quote from: Exactopposite on April 28, 2006, 09:09:45 PM
i jsut did a few of the mods while i had time. i replaced the 33k resistor with a 100k (vocal mod)

You might try something more like 68k here.


lacto

Just my two cents worth, but I have gotten heavily into modding wahs the  past several months and for the mid resistor, the 1.5K,
2.2K is too much IMO, as 1.6K would be noticeable. Raising the mid resistor also flattens out the sweep removing the abrupt change
from low to high, not necessarily a desireable thing. Also, not sure what .01uf cap you are refering to the sweep or the input cap ,both are sensitive but especially the sweep cap. It should be adjusted in increments like from .01uf to .011 etc, inching your way up. I would put your original .01uf cap back in and and see what you think of the low end of the sweep. As far as resistors go the most significant changes are made with the bass resistor, 470ohm, and the Q resistor in parallel with the inductor. For the Q you should get resistor values in between 33K and 100K and experiment as somewhere in between is the ideal balance of vocality and quackiness. A trimpot for the Q is a great idea so you can just dial in the value without having to solder/unsolder several times. Have fun it is rewarding and maddening modding wahs, a simple circuit with so much variability.

Exactopposite

Quote from: Toney on April 29, 2006, 02:48:24 AM
Quote from: Exactopposite on April 28, 2006, 09:09:45 PM
i jsut did a few of the mods while i had time. i replaced the 33k resistor with a 100k (vocal mod)

You might try something more like 68k here.



i didn't have a 68k around to try there. the vox clyde schematic here ( http://fuzzcentral.tripod.com/mccoy.html ) has a 100k there so i figured i'd try that.

Exactopposite

Quote from: lacto on April 29, 2006, 03:14:46 AM
Just my two cents worth, but I have gotten heavily into modding wahs the  past several months and for the mid resistor, the 1.5K,
2.2K is too much IMO, as 1.6K would be noticeable. Raising the mid resistor also flattens out the sweep removing the abrupt change
from low to high, not necessarily a desireable thing. Also, not sure what .01uf cap you are refering to the sweep or the input cap ,both are sensitive but especially the sweep cap. It should be adjusted in increments like from .01uf to .011 etc, inching your way up. I would put your original .01uf cap back in and and see what you think of the low end of the sweep. As far as resistors go the most significant changes are made with the bass resistor, 470ohm, and the Q resistor in parallel with the inductor. For the Q you should get resistor values in between 33K and 100K and experiment as somewhere in between is the ideal balance of vocality and quackiness. A trimpot for the Q is a great idea so you can just dial in the value without having to solder/unsolder several times. Have fun it is rewarding and maddening modding wahs, a simple circuit with so much variability.

the link i got the info form is above. you can see there which cap i'm talking about. the cap is listed as being .022 in the clyde mccoy schematic i have. as far as the mid resistor, i tried 2.2k since that's what was listed ont he info i had. when i get home form work i'll see what other values i have around to try there. thanks for your input.

lacto

The inductor is the heart of a wah circuit. You really can't make any adjustments until you decide upon the inductor you will
use and tune the rest of the circuit to that. When you get the yellow fasel, that will change everything and you will have to
tune it up accordingly. The article you are using does refer to the sweep cap and suggests first a .015 and then the .022uf
which is way to much IMO. A Clyde wah used a 100K for the Q, but that has a totally different inductor, a halo inductor, which
is quite different from a fasel inductor. Good luck, most any changes you make will be an improvement from the stock version
of your wah.

Exactopposite

Quote from: lacto on April 29, 2006, 04:22:28 PM
The inductor is the heart of a wah circuit. You really can't make any adjustments until you decide upon the inductor you will
use and tune the rest of the circuit to that. When you get the yellow fasel, that will change everything and you will have to
tune it up accordingly. The article you are using does refer to the sweep cap and suggests first a .015 and then the .022uf
which is way to much IMO. A Clyde wah used a 100K for the Q, but that has a totally different inductor, a halo inductor, which
is quite different from a fasel inductor. Good luck, most any changes you make will be an improvement from the stock version
of your wah.

the inductor, pot and switch came in today. i just got in from work and i'm not sure that i'll bother with it 2nite. i'll get them in there 2moro. as for the other parts, i put them in but nothing is set in stone. after i get the rest of this stuff int here i'll see where i stand and take it form there.

thanks for your input. i really appreciate it

Exactopposite

Quote from: Toney on April 29, 2006, 02:48:24 AM
Quote from: Exactopposite on April 28, 2006, 09:09:45 PM
i jsut did a few of the mods while i had time. i replaced the 33k resistor with a 100k (vocal mod)

You might try something more like 68k here.



like i said above, i didn't have a 68k availible so i tried the 100. i'll probablly get a trim  pot for this. i'll see what toher resistors i have availible to try. i stopped by radio shack after work but they were already closed. i think i'll make up a list and head down to my local electronics store to get some stuff.

Exactopposite

ok so here's where things are righ tnow.

i did the true bypass mod. i replaced the switch with a TPDT switch (i'll add an LED later). i replaced the stock inductor with the yellow fasel, and the pot with the fulltone pot.

i put the .01 cap back in and the sweep went back to normal, so it'll stay there for now. i also put in a 68k resistor instead of the 100k i had in for the vocal mod. i realided i had a couple of 68k reistors i ahd overlooked the toher day. i sitll ahve the 2.2k in to increase the mids. i don't have another resistor between the 2.2k and the stock value of 1.5k right now, so i left the 2.2k in. i replaced the 68k input resistor with a 47k so i don't lose volume when the pedal is turned on.

as it stands right now it sounds pretty good. it's hard for me to comapre it to stock becasue i really neer used it since i have my colorsound. it doesn't sound nearly as thin or as harsh as i remember stock crybaby's sounding tho.  it's very vocal sounding now. the high end on it is still pretty shrill, but i don't want to adjust the pot back anymore than i already ahve as there is a lil bit of dead space on the bass end of the sweep as it is. what's the method of finding a happy medium between killing some of that treble and still having the ENTIRE sweep be useful?  really it's not so bad as it is right now. i don't hang out on that treble end of the sweep anyway.

BUT...there is a bit of troulbe in paradise. when the effect is on the switch makes noise whenever the rocker touches it. if i do the same thing wiht the effect off there is no noise. i'm not sure what's causing that. if any of you have ideas i'd be glad to hear them.

other than the issue with the switch i'm pretty satisfied overall. i'll have the chance 2moro to give it a more thorough test and compare it to the colorsound. it needs a bit more tweaking but it's not far off where i want it to be right now.

Ed G.

Quote from: Exactopposite on April 30, 2006, 08:33:48 PM
BUT...there is a bit of troulbe in paradise. when the effect is on the switch makes noise whenever the rocker touches it. if i do the same thing wiht the effect off there is no noise. i'm not sure what's causing that. if any of you have ideas i'd be glad to hear them.

Not sure if it's the same thing, but I was fixing a friend's wah, he said it didn't wah, just got louder. I got the wah and plugged it in, and it worked, strange. But I hear some noises just by barely tapping on the casing, anything. The wah was microphonic, for lack of a better word. I went and I reheated every solder join, hoping that would do it. Then the wah just died. Acted like my friend said it did. I replaced the inductor with one I had lying around and that did it. Apparently the inductor was on the verge of dying, maybe a wire was loose somewhere and heating it up did it in, but I've never heard of that one before.