Crybaby GCB-95 schematic with correct component designators

[TejonSorceror]

Greetings, all. I'm working on some mods to the GCB-95 Crybaby (wah pedal). There's lots of good information about this circuit out there, notably at electrosmash.com and geofex.com. However, I couldn't find any version of the schematic diagram with component numbering which corresponds to the actual PCB from Dunlop. (Does anyone know of such? I'd still like to find it, as my own efforts are slightly primitive.) Also, the schematic as seen on the sites I mentioned appears to be a version which has been widely copied and distributed -- but unfortunately it has an error (beyond just the numbering), which everyone seems to copy and propagate without checking.

So to give myself something better to work from in my experimentation, I drew up a pen-n-paper version of the schematic with the correct refdes numbers, and with the aforementioned error fixed. Here's a link, in case it helps others:

Crybaby GCB-95 schematic -- with correct component designators!

I am indebted to the work of others on the sites geofex.com and electrosmash.com, where much info can be found about this interesting circu...

crybaby-schematic.blogspot.com

BTW, if in doubt, you can tell that you've got the ubiquitous, erroneous schematic, because it labels the input transistor, which Dunlop calls Q3, as "Q0"; and associated passive components are labeled things like "Rin3".

--Benjamin Ketcham-McGrath

 

[generic202]

You may need to consider the fact that there are different versions of GCB-95 with some changes over the years. For example, some GCB-95s don't have input buffer stage, some don't have any component labels on the board, some have different component layouts, etc. That's probably why there are inconsistencies between schematics on the web. I'm sure your schematic is "correct" to the version that you worked with but that does not mean the others are wrong unless you have verified with every version of GCB-95s out there.