gcb 95 wah circuit different

[Night0wl]

Hi all,

I am going to mod my "Original CryBaby" but I have a slight problem. All the pics of the circuits on the various sites are different to the one in my Wah. The closest I can get is here (top row of pics, 2nd one from the right - Vox V847). The difference is my circuit board is a pale brown colour (not green like in the pic) and I have a 100uF polarised cap and a diode at the top right of the pic (between the top right resistor and the white rectangle on the right). Other than different coloured caps, everything else is the same as the pic. The blue caps (left and right) in the pic are green in mine and the other 2 blue caps (middle and lower) are large red ones in mine.

I bought this pedal in about 1989 and it says "Original CryBaby Model GCB-95" on the base plate.

Further down the page on the link above there is another pic of a V847 circuit illustrating the resistor and cap sizes but this one has no trannys or diode & polar cap where the "Vox" symbol is. I assume the rest of the layout would be the same?

Thanks,
Shane

[Paul Marossy]

From your description, somewhere on the board, it should say "Rev D". I wouldn't worry about the different color caps, they'll work just the same as the one in the picture. The schematic/layout should be the same regardless if the PCB is brown or green.

The differences between yours and the picture is just due to them using parts from different sources/manufacturers over time. The part values are the same, though. 

[Dai H.]

is it like this one?

http://www.pisotones.com/varios/CryBaby/CryBaby.htm

I guess there are also ones with a smaller inductor as well as maybe a little board with a couple parts (filtering?). You should probably take a pencil and paper, plus continuity/ohms function on your DVM, and draw everything out. Or at least stare at it until you figure where things are. It's like the older ones I would think.

[Night0wl]

Dai H, it isn't like the one in the link. It is closer to the Vox one I originally posted. I will post a photo of it later today when I finish work.

Cheers,
Shane

[woulfer]

I've got the circuit in the link!! It looks the same, except the electrolitic is radial instead of axial. I'm gonna be modding it for a friend.(True Bypass, Q pot, External power jack, etc.) Is everything pretty much the same, value wise, as the later revs?

[Dai H.]

haven't looked closely, but it appears more like early Vox/Crybaby than later full-blown GCB-95. BTW, how does it sound?

[woulfer]

It doesn't sound that good. A friend of mine got it off ebay last week. He is running in throught a Lancaster Essix 15, with a custom built tube JCM800 clone preamp in a pedal. It does OK with a clean sound, but the volume drops a bit, and it just doesn't quack as much as it should. Put it in front of some gain, and you can hardly tell it's on, except for the volume drop.

[Dai H.]

thanks woulfer! I haven't messed with my wahs in a couple of months, but (from experimenting) I was starting to think that the amp needs to be run clean to get a good wah effect. Was starting to suspect that Jimi was getting mainly Fuzz Face distortion instead of (or much more than) Marshall distortion. Got to move some junk out of the way so I can do some soldering again...

[Noplasticrobots]

Does your board look more like this?

http://www.geofex.com/Article_Folders/wahmod/wahboard.jpg

[Dai H.]

that looks like it might be from a recent Vox V847. FWIW the two in the links above look the same except for the parts. The V847? board pic also seemed to use the same basic layout.

[Night0wl]

Does your board look more like this?

http://www.geofex.com/Article_Folders/wahmod/wahboard.jpg

Yeah apart from different coloured caps, my circuit is the same as the one in that link. My board has Dunlop printed on it aswell.

[Dai H.]

The closest I can get is here (top row of pics, 2nd one from the right - Vox V847).

aarrgh, I kept thinking second one from the left... 

DOH!!!