Modding a GCB-95 to ZW-45 or DB01 specs

[ledvedder]

Does anyone know if it's possible to mod a standard GCB-95 to ZW-45 or DB01 specs?

[Joe Hart]

My understanding is that the ZW wah uses the standard Crybaby board, so you should be able to do that conversion. The DB one uses some op-amps, so it may not be as easy. Hope this helps.
-Joe Hart

[Govmnt_Lacky]

I would be interested in this too.

I guess the best way to do it would be to find a schematic or layout for the ZW-45 or DB01, find the differences, and work from there. It might just be a matter of different component values and a different inductor.
The GCB-95 is all over the place so you should have no problem finding it.

[Govmnt_Lacky]

Looks like the only changes between the ZW-45 and the GCB-95 is the sweep cap is changed (22n) and the input gain stage emitter resistor.

[ledvedder]

Looks like the only changes between the ZW-45 and the GCB-95 is the sweep cap is changed (22n) and the input gain stage emitter resistor.

But, wouldn't that just make it a Hendrix wah?

[Joe Hart]

It's supposedly almost identical to the Hendrix wah. That's what Zakk wanted. But compare schematics and see.
-Joe Hart

[ledvedder]

Looks like the only changes between the ZW-45 and the GCB-95 is the sweep cap is changed (22n) and the input gain stage emitter resistor.

What's the input gain stage emitter resistor?

[Govmnt_Lacky]

What's the input gain stage emitter resistor?

Exactly what it says it is. This is the resistor that is directly adjacent to the emitter leg of the input transistor.

The sweep cap is the capacitor that is immediately after the parallel inductor/33K resistor stage. In the GCB-95 it is .01uF. In the ZW-45 it is .022uF.

[ledvedder]

What's the input gain stage emitter resistor?

Exactly what it says it is. This is the resistor that is directly adjacent to the emitter leg of the input transistor.

The sweep cap is the capacitor that is immediately after the parallel inductor/33K resistor stage. In the GCB-95 it is .01uF. In the ZW-45 it is .022uF.

OK, I understand the sweep cap value on the ZW is .022uF.  But, what is the input gain stage emitter resistor's value on the ZW?

[Govmnt_Lacky]

"Give a man a fish and he eats for a day....

Teach a man to fish and he eats for a lifetime." 

[Joe Hart]

"Give a man a fish and he eats for a day....

Teach a man to fish and he eats for a lifetime." 

I always here this and it's so true...

Google is your friend.

-Joe Hart

[anti-idiot]

Main changes are (besides the op-amp or fet buffers, the boosts thingies or pretty lights):

Re1: 470 (GCB-95/DB-01) and 390 (JH-1/ZW-45)

Cf: 10n (GCB-95), 22n (JH/ZW) and multiple caps on DB


and 1k trimpot in series w/inductor (Q control) on DB-01.

Now, go read RG's article to find out what Re1 and Cf means.

Cheers!

[Bullet79]

the same GCB-95C pcb with red fasel and 1% metal film resistor except for R13 (1M8) and R17 (jumper)... and .022 sweep cap...
sure u'll notice big diff after doing all the stuff mentioned... (i have done it but with .015uf for the sweep cap) .. and true-bypass dpdt..  metal film resistor are good..!!!

[Joe Hart]

...and 1% metal film resistor... metal film resistor are good..!!!

Did you replace all the resistors with metal film? And did you notice a huge difference? And what was it, just lower noise? I'm very curious. Thanks!
-Joe Hart

[Bullet79]

i've got 2 GCB95 crybaby... stock pcb dpdt true-bypass hot potz 2 pot, and the other one fitted with red fasel,clairostat 'Hot potz 1' and all metal film resistor... seriously you can hear the diffrence when comparing them side by side.. i dunno whether the metal film or the fasel or the taper of that 'clairostat' pots that makes the diff...  but what i can say is the sound is more LIVE..!! 

[Joe Hart]

i've got 2 GCB95 crybaby... stock pcb dpdt true-bypass hot potz 2 pot, and the other one fitted with red fasel,clairostat 'Hot potz 1' and all metal film resistor... seriously you can hear the diffrence when comparing them side by side.. i dunno whether the metal film or the fasel or the taper of that 'clairostat' pots that makes the diff...  but what i can say is the sound is more LIVE..!! 

Oh okay. I would say that the other differences account for much more than just the resistor type does. That being said, is it quieter? My Wah hisses a bit (I know they all do because of the circuit emphasizing higher frequencies). Thanks!
-Joe Hart

[Bullet79]

no noise at clean channel even at loud volume level... i never complain when in hi-gain channel... supposed to be like that... wild feedbacking to the max.. you could try to play with the transistor hfe's,.. it really does tweaking the wah presence....  lower hfe makes the wah a bit dull while higher ones make it screams.... the clairostat pots (dunlop hot potz 1) also contribute to good tones... maybe the taper is diffn then hot potz 2..

both of my wah still retain stock the buffer...

[hailtoarms]

I have been doing lots of research into modding this pedal to sound like the zw-45. Like said before, all the resistors have been swapped for 1/4 watt 1% metal film. I really don't see the need, though I don't doubt the sound difference. The only two resistors that are the same are R13 and R17. They also changed out the caps for what looks like some wanna be orange drops. They may, be i don't know. I plan on changing the "sweep" cap to .022uF. And of course the fasel, which I hope will make a noticeable sound difference. I also plan to change the R1 resistor, which is a 1.5K to a 2K for some added midrange. The 95 I have already has the 390 in the R9 spot, which is less work for me. In the end I hope to have a bigger sounding wah with a little of the Zakk Wylde attitude. I will let you guys know how it turns out in a week or so.


by the way i got my wah for free so if I end up having a half ass zw-45 for only $35 its a win win

[Bullet79]

something like this..??



i found a lot of tonal change between dunlop Hot Potz 1 (clarostat) and the later Hot potz 2 (black),.. 

[hailtoarms]

That's awesome. Did you change out everything to mach the zw-45? Do you think the resistor change will make that big of a difference?