Improving my Crybaby gcb-95 (photoessay)

A forum devoted to mod, tips and suggestions for upgrading and rehousing your VERY CHEAP commercial stompbox to near boutique excellence.
Post Reply
User avatar
grrrunge
Diode Debunker
Information
Posts: 810
Joined: 20 Mar 2010, 10:51
Completed builds: Loads!
Location: Copenhagen, Denmark
Has thanked: 50 times
Been thanked: 206 times
Contact:

Post by grrrunge »

bajaman wrote:Forget about Teese wahs and all the bullshit about specially manufactured parts etc., here is how to make any standard cry baby wah sound much better. :wink:
First - replace all those shitty little blue capacitors with some better quality ones - I used those little grey MKT film types, but you could use xicon film for still better results. (They are 10n x 2, and 220n x 2).
Second - find the 4.7uf electrolytic capacitor and it's 82k ohm bypass resistor - replace them with a 3.3uf BP paralleled with a 680n film type (for close to 4uf) and a 100k metal film resistor (or metal oxide).
Third - replace the 390 ohm resistor with a 510 ohm ( or parallel 2 x 1k ohm)
That is it :wink: - just plug in your guitar and enjoy wah wah sounds ( not woh woh as in the stock GCB95)

No need for special taper pots, fasel inductors or any of the other bullshit stuff - just good quality capacitors and the correct value resistors is all you need
Cheers
bajaman
Inspired by the above post, I decided to rip my old crybaby apart, as she's been on the shelf for years now. Who knows, maybe I'll fall in love with her again :)

Digging teh interwebs yielded loads of grainy lo-resolution pictures of the circuit board, so i decided on starting out by making these:





Parts list is as follows:
D1: 1N5239B (9,1V zener)

Q1: MPSA18
Q2: MPSA18
Q3: MPSA13

C1: 10nF
C2: N/A
C3: 4,7uF
C4: 220uF
C5: 10nF
C6: 0,22uF
C8: 0,22uF
C9: 10nF (code 103)
C10: 22pF (code 220)
C11: 100nF (code 104)

J3: N/A

R1: 1,5K
R2: 1K
R3: 82K
R4: 22K
R5: 33K
R6: 470K
R7: 470K
R8: 10K
R9: 390R
R13: 1,8M
R14: 10K
R15: 68K
R16: 2,2M
R17: 0R
R18: 1K

I'll be replacing the caps with proper film equvalents, and all resistors with low tolerance metal film type resistors.
Next step: applying Bajaman's mods on the drawing board.
Does anyone have a proper schematic of this pedal? The ones i could find via google were pretty crappy, and some of the values were different...
A true believer in the magic of Sherwood Forest Pedal Pirates
---
New base of operations: http://www.knucklehead.dk

User avatar
Fredenando
Breadboard Brother
Information
Posts: 129
Joined: 20 Mar 2010, 11:37
Has thanked: 453 times
Been thanked: 90 times

Post by Fredenando »


User avatar
grrrunge
Diode Debunker
Information
Posts: 810
Joined: 20 Mar 2010, 10:51
Completed builds: Loads!
Location: Copenhagen, Denmark
Has thanked: 50 times
Been thanked: 206 times
Contact:

Post by grrrunge »

Thanks! at least the quality is good. The part names and numbers are weird though :scratch: I'm going back to the drawing board.
A true believer in the magic of Sherwood Forest Pedal Pirates
---
New base of operations: http://www.knucklehead.dk

User avatar
grrrunge
Diode Debunker
Information
Posts: 810
Joined: 20 Mar 2010, 10:51
Completed builds: Loads!
Location: Copenhagen, Denmark
Has thanked: 50 times
Been thanked: 206 times
Contact:

Post by grrrunge »

Slight update on a slooooow project :D
Here's a schematic redraw, with the right component designations corresponding to the PCB:
GCB95.png
A true believer in the magic of Sherwood Forest Pedal Pirates
---
New base of operations: http://www.knucklehead.dk

User avatar
GeoMan
Information
Posts: 1
Joined: 03 Jan 2016, 22:23

Post by GeoMan »

Thank you for this schematic. I'm working on some mods to my CryBaby and this is the first one that appears to be labeled accurately when matching the values with my DMM. I appreciate the work you put into it.

Cheers.

Post Reply