Modify a Cry-baby... Any ideas or tips?

Started by JJRockford, October 02, 2003, 06:51:53 AM

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JJRockford

I would like to modify my Dunlop Cry-baby, but I haven't found any schems on the internet... Any ideas? I would like to be able to adjust which frequenzies to boost, how much to boost, a tonecontrol (most wha's I tested are a little to "thin", maybe it's bad technique from me :)), and a led so I can see if the wha is on or off (I guess most of you have been in live-situations when you don't really hear your amp?).

Thanks!
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Please visit VII Gates official homepage at http://www.sevengates.se


Jim Jones

Hey there,

Stuart Castledine has some excellent info at his site, too!  Check out http://www.green-fuz.freeserve.co.uk/wah.html

Jim

Ansil

change the inductor,  try a radioshack transformer,  a bass pickup, with or without, a magnet on it, a small audio choke from an electronic crap board off a modem card.  a guitar pickup

Paul Marossy

To my ears, the new manufacture Dunlop CryBaby wahs sound a little lame right out of the box. The tone sounds thin, the bass response is a little weak, and they are not very vocal sounding at all. I originally bought my CryBaby just for the shell. I was intending to put a vintage V847 wah circuit in it, but with my current setup, I could not make it stop humming no matter what I tried to do. So, I looked into what modifications I could do to make the new GCB-95 circuit sound better. There are a few different versions of circuit boards in the Dunlop wahs, each with different layouts and slightly different components. My wah has the GCB-95, Rev. G PCB in it. Refer to this picture for the following:

http://www.green-fuz.freeserve.co.uk/effects/gcb95.jpg

Stuart Castledine's wah wah mods page gave me the basic blueprint for tailoring the new CryBaby circuit to my liking. Here's what I did:

I wanted the sweep to sound a little thicker and I wanted a little more bass and midrange response. So I changed the sweep cap from the stock 0.01uF to a 0.012uF. (The sweep cap is between the emitter of Q2 and the inductor) This gives a little more bass response and makes it sound fuller on the high end without sacrificing the treble response too much.

To increase the midrange, I replaced the stock 1.5K resistor between the base of Q2 and the inductor to a 2.2K resistor. This also helps to smooth out the response between the bass and treble.

I also wanted my wah to sound more vocal, so I replaced the 33K resistor in parallel with the inductor with a 47K resistor instead of the recommended 68K. I really like the way this sounds, much, much more vocal sounding than stock. (This may also be because of the other modifications I have made)

Finally, I replaced the stock 470 ohm resistor at the emitter of Q1 with a 270 ohm resistor. This gives the circuit a little more gain, and it also helps to increase bass response some, too. Now my volume doesn't drop off the way it did before I made these modifications.

The only other thing that I may consider down the road, is replacing the stock inductor with a replica "stack-of-dimes" type or a new manufacture Fasel one. I'm still not fully convinced that the new Fasels sound as good as the original ones did, though. I probably will leave things as the are, since it sounds good to me. I have not measured the inductance of the inductor on my circuit board, but from the information I can find, it appears that it is 660mH instead of the original 500mH used in the vintage Vox Clyde McCoys. But then again, most of the inductors made were all considerably above the 500mH inductors in the first wah pedals that were manufactured. The old wah pedals were just as highly variable in sound as the original Fuzz Faces were.

Now I am quite happy with the sounds this wah makes. It sounds just about as good as my ill-fated vintage wah circuit does! It costs five dollars or less for the parts and takes less than an hour to perform these modifications with the careful use of some de-soldering braid.

Hope that helps.

Adam Shame

Thanks for all the great information!  I have a dead Crybaby that I want to ressurect, and this information will sure help!
Q: What do you get when you cross an owl with a bungee cord?

A: My Ass

JJRockford

Yes, that was a lot of great information! Thanks!!
*************************
Please visit VII Gates official homepage at http://www.sevengates.se

R.G.

Have you read "The Technology of Wah Pedals" at GEO?
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.