Dunlop cry baby classic GCB-95 / GCB-95 F wha effect level adjust mod

[Rusty]

Dunlop cry baby classic GCB 95 / GCB 95 F wha effect level attenuation trimmer adjust mod.

If you own one of these cry baby models or similar and you notice that when you switch the wha pedal on that there is a big guitar volume signal gain boost compared to the normal pedal off signal, then here's a simple mod that you can do.

You will need a 1M Ω mini pot, a little piece of heat shrink tube, and a little amount of glue or similar to secure the pot inside, and a little piece of wire to extend one of the wires on the ribbon cable to the pot and another little piece that go's back to the switch.

I have figured out what is what at the switch and have drawn up a block schematic diagram for you to see what is going on.

So then, here we go.

1. Cut the ribbon cable off the DPDT switch circuit board as close to the small switch circuit board mounted on the switch and remove that little circuit board, it's of no use any more.

2. Carefully separate the ribbon cable strands with a blade, strip the ends of the wires, prime them with solder to get ready

3. You can put some heat shrink tube on the wires, I was lucky enough to have some different coloured stuff lying around, but not necessary if you follow through these instructions. (See the photo 3.)

4. On the switch, solder in a jumper link wire between the two top and bottom solder lugs to the right hand side. (see the diagram and photo.)

5. The ribbon cable from top to bottom is, again see the diagram and photos that I have posted.
                     1, output, (yellow,)
                     2, wha circuit output, (blue)
                     3, wha circuit in, (red) 
                     4, input, (green)

6, Solder on # 1 (yellow, top) of the ribbon to the top centre lug of the switch and solder #4 (green, bottom) of the ribbon cable to the bottom centre lug of the switch. Then solder #3 (red) to the bottom left lug on the switch.

It's just #2 (blue) of the ribbon cable we are dealing with now.

7, Jumper wire the left and centre tags on the pot together with a tiny piece of wire to make it rheostat style.

8, Extend wire no' # 2 (blue) on the ribbon cable, heat shrink shield the solder joint, then solder that wire to the centre tag/lug on the pot.

9, With another short piece of wire, solder it to the right hand side tag/lug of the pot, then solder the other end to the top left of the switch.

10, now all you have to do is secure the pot inside the pedal.
(I used sticky back foam tape to do mine as it's tidy, but it's up to you what you use to do this, as long as you don't ruin the pot with glue or whatever you use.)

Plug it in to your guitar and amp and play with the cry baby off and on.

From here you adjust the pot to get the on and off guitar signal exactly equal to each other.
When you get it equal screw the bottom cover back on and that's it.

This mod DOES not affect the tone of the wha cry baby effect.

Well that's how I have done it, please look at my diagram and pics for clarity of what I am talking about.

Good luck and happy wha, wha-ing. 

Rusty.

[rabidgerry]

What a great and thorough mod!

I don't have a wha but it would be of use to someone I'm sure 

[vansinn]

Cool ;)