Slight OT: JH-1 and CryBaby (GCB-95) Wahs

[brett]

What are the differences between these wahs?  (links to schematics?)

Which do people prefer?

[Jim Jones]

Hi Brett,

I don't have any schematics, but I didn't mind the Hendrix wah when I played through it years ago.  It was way fuller sounding than the awful GCB-95.  I own the latter and it is the crappiest, trebliest piece of wah junk made, IMHO of course.  

Jim

[Arn C.]

[/quote]GCB-95. I own the latter and it is the crappiest, trebliest piece of wah junk made, IMHO of course

Jim,
     I got one in trade from a friend I did some work for and I modded it.  I gave it to my son.   It is way too cool now.  I have all the modding info if you need it.  If not and you don't want or use it, I will buy it off you or trade for it.  But you will like it after modding it!!!
Arn C.

[Marcos - Munky]

I have the schematics, and I found two differences. The JH-1 uses a MPSA18 for the first transistor, and GCB-95 uses a MPSA13, and the JH-1 have a 0.01uF cap in parallel with the inductor. Maybe there's more differences, but I found only these two.

[Jim Jones]

Hi Arn,

I did start to mess with it after finding Stuart Castledine's great site.  After some monkeying I got it sounding better but in the process I wound up having some traces lift.  I plan on making another board from scratch and trying again though.

Did you replace the inductor, too?  I really want a nice pukey-sounding wah - "White Room" is it for me.

Jim

[phillip]

The schematic for the JH-1 wah is on Justin Philpott's Effectronics schematics site:

http://www.geocities.com/j4_student/schematics.htm

Scroll down to the "wahs" section and it's the third link down

They've added two new capacitors: there's a 0.022uF capacitor between the wiper arm of the wah pot and ground, and there's also an extra 0.01uF capacitor in parallel with the inductor.  Other than that, it's the same as the GCB-95.

Phillip

[Arn C.]

Jim,
   

Did you replace the inductor, too?

No!

Peace!
Arn

[Jim Jones]

Kept the inductor, eh...hmm...

If you don't mind letting me know what you did to yours please send me an email!  house-of-jim@shaw.ca

Thanks!

Jim

[phillip]

I would do some standard wah mods to it...shouldn't change the overall vibe of the JH-1 mods.

1.  Convert to true bypass using a DPDT or 3PDT switch
2.  Remove the input buffer (no longer needed with true bypass)
3.  Change the 68K input resistor to 47K to make it a little louder
4.  Change the 33K resistor parallel to the inductor to 68K
5.  Replace the MPSA18 transistors with BC109C with gains of 300-350 (highest gain of the two in Q1 position)
6.  Add a JFET output buffer so it will get along with Fuzz Faces and ToneBenders more

Those 6 things are mods that I usually do to wah pedals that friends bring me to modify.  They really help the wah sound a LOT better

Phillip

[Prive]

There's enough difference, JH-1 is darker, don't have the crispy treble end, but to my ears is more "plastic tone".
Is easy to try, in the GCB-95 there is place to make the changes, the pcb have holes and is ready to mod.
I hope it helps you.

Saludos, Marcelo.

[Prive]

There's enough difference, JH-1 is darker, don't have the crispy treble end, but to my ears is more "plastic tone".
The 2 caps made some audible changes in tone.
Is easy to try, in the GCB-95 there is place to make the changes, the pcb have holes and is ready to mod.
I hope it helps you.

Saludos, Marcelo.

[brett]

Thanks everyone.  I was wondering about the merits of purchasing a GCB-95 vs the JH-1.  It seems that I can easily mod a crybaby to JH-1 specs.  Excellent.

[Prive]

Buy the cheapest and add or take off two caps to your desire.

Saludos Marcelo.

[jimbob]

Jim jones- I was modding my gcb-95 had the same problm with the lifting--im making a new board as well.. Maybe they were just made cheap?

[Jim Jones]

Hey Jimbob,

I don't know if the Dunlop boards are overly cheap - I've had problems with repeated de-soldering on other boards too.  PCB's just aren't meant for that kind of abuse, (that's why I do my amp builds on eyelet boards.)  

Good luck with your new board - I guess we'll both be working on those.

By the way, what sort of wah tone are you looking for personally?  Any song reference in particular?

Jim

[jimbob]

The wah was one of my first mods ever--that might also explain it. But Greenfuzz had a great site id been looking at for mods. Im not sure what kind of sound im looking for really--i suppose ill have to build them all.. And i probably will over a period of time--that way ill have more choices. I wish i had a siple layout for the vox wahs..im not good at building from schem yet. but i have 2 dunlop wah shells i plan to fill..1 with a vox and the other with..?...not sure yet.

[Gearbuilder]

Hi ,
I've got two Jim Dunlop models ,a VOX reissue and a real old VOX here's my test results :

- Cry baby :thin trebles
- JH 1 :more voice but muddy bass (little black can inductor)

-VOX reissue : it's ok only for the enclosure,bad effect !

The vintage VOX  is the best (it's the model with the red Fasel inductor )of my wha-wha's.The inductor is VERY important.I've  tried the Fasel on the JH1 ,and it a lot better than his little black can inductor.
Maybe i'm goig to buy a Red Fasel at Jim Dunlop ,just for try the new inductors in my VOX reissue.The JH1 sounds better than this one !!
Bruno