GCB-95 mods?

moeburn · August 16, 2005, 07:49:58 PM

I'm ordering a GCB-95, I don't really know how the interior is layed out and how much stuff I can fit in there since I haven't seen it yet. Can anyone reccomend which mods to do first?

Michael Allen · August 16, 2005, 08:28:07 PM

I think Doug Hammond had some Crybaby mods on his site. I think it entailed just adding a JFet input stage and tweaking some other resistor values. Do a forum search and you should find tons more

jimbob · August 16, 2005, 08:29:01 PM

Toss the board in the trash- buy - or perf a board, and check out the GGG site and Tonepads- Also Phillip has a cool one too.

george · August 16, 2005, 10:34:16 PM

Quote from: jimbobToss the board in the trash

don't understand why you'd do that. You'd only put yourself through unnecessary work to recreate what is much the same circuit as any "classic" wah out there.

My advice:

- make it true bypass
- remove the input buffer
- change the inductor to something decent eg red or yellow reissue Fasel

There's instructions for the first 2 at http://members01.chello.se/pastorn/fx/mods/dunlop.htm

It's a nice step-by-step pictorial guide

Then maybe you can futz with other mods that are also documented on this site. I like the 470 ohm resistor changed to 150 ohm (gives more bass)

C Bradley · August 17, 2005, 09:32:00 AM

I love my GCB-95 Crybaby, and all I did was this:

1) changed input cap to .1uF
2) changed Q1's emitter resistor from 390 to 220 Ohm
3) changed the 39k resistor in parallel with the inductor to 47k

Check Geofex's "Technology of the Wah" for more mods.

One thing that I'm considering doing to my wah is changing the controller to an LED/LDR setup to eliminate the scratchy pot noise. Has anyone done this? Did it change the sound of your wah?

Doug_H · August 17, 2005, 09:49:49 AM

Quote from: Michael AllenI think Doug Hammond had some Crybaby mods on his site. I think it entailed just adding a JFet input stage and tweaking some other resistor values. Do a forum search and you should find tons more

At this point in time I think I'd recommend subbing the switch with a dpdt wired for true-bypass and leaving out the input buffer. I'm having problems with buffered effects getting along with my rangemaster in the same chain. I need to fix my wah anyway so I figure I'll pull out the buffer and swap the switch when I get around to the repairs.

The gain and Q mods are cool though. Thanks to R.G.'s wah article.

Doug

Paul Marossy · August 17, 2005, 10:30:12 AM

Here's what I did with my GCB-95: http://www.diyguitarist.com/DIYStompboxes/WahMod.htm
It was a definite improvement.

moeburn · August 17, 2005, 11:30:24 AM

Is there room in the case for a rotary switch for sweep caps?

Paul Marossy · August 17, 2005, 11:36:42 AM

Quote from: moeburnIs there room in the case for a rotary switch for sweep caps?

Most people drill a hole in the side of the shell and mount the rotary switch there. But, there should be enough room inside to internally mount one, with some careful planning.

bass_econo · August 17, 2005, 11:41:48 AM

Quote from: Paul MarossyHere's what I did with my GCB-95: http://www.diyguitarist.com/DIYStompboxes/WahMod.htm
It was a definite improvement.

I'll second Paul's comment... I did this mod to my friends and he loves it now.

Also I would not suggest doing the Volume\Wah mod since the volume will not reduce to zero. You will have about mid-volume to unity. Unless you like that...

vanhansen · August 17, 2005, 11:47:30 AM

Here's what I did to mine:
http://diy.erikhansen.net/gcb95.htm

Pretty much the same that is everywhere else except I added the two caps to make it a JH-1 Wah.

Paul Marossy · August 17, 2005, 12:48:20 PM

QuoteI'll second Paul's comment... I did this mod to my friends and he loves it now

Cool!

bass_econo · August 17, 2005, 02:03:15 PM

BTW, not to thread-jack but Paul how old is your Makenna? Mine turns 3 Sunday.

Paul Marossy · August 17, 2005, 02:07:03 PM

Quote from: bass_econoBTW, not to thread-jack but Paul how old is your Makenna? Mine turns 3 Sunday.

She's gonna be four in October! My son, Luke, will be 2 in December. Seems like the were born just the other day. :shock:

bass_econo · August 17, 2005, 02:18:16 PM

Well Makenna is my only one... for now, but yes they grow up so fast!!!

Paul Marossy · August 17, 2005, 02:30:27 PM

Quote from: bass_econoWell Makenna is my only one... for now, but yes they grow up so fast!!!

Oh, so your girl is also named Makenna? That's cool. Do you know what the name actually means? The only thing I have been able to find out is that it's Gallic (I think) for "happiness". She certainly is the happiest and silliest girl I have ever seen! (not to mention that she makes me happy)

moeburn · August 22, 2005, 04:30:59 PM

i replaced the inductor's 33k resistor with a 47k, and i replaced the 1.5k resistor with a 2.0k. I don't like it. The only 'wah' in the pedal is right in the middle, about %5 of the pedal's travel. It is a very non-linear curve. I'm going to put the old parts back in.

Paul Marossy · August 22, 2005, 04:33:17 PM

Quote from: moeburni replaced the inductor's 33k resistor with a 47k, and i replaced the 1.5k resistor with a 2.0k. I don't like it. The only 'wah' in the pedal is right in the middle, about %5 of the pedal's travel. It is a very non-linear curve. I'm going to put the old parts back in.

Really?! Something sounds strange - mine didn't respond that way... :wink:

moeburn · August 22, 2005, 05:05:11 PM

So how do I widen the range of the wah? I don't think its the 0.01uF capacitor, that only selects the range.

Paul Marossy · August 22, 2005, 05:15:18 PM

Quote from: moeburnSo how do I widen the range of the wah? I don't think its the 0.01uF capacitor, that only selects the range.

The "sweep cap" will shift the frequency range the most of all the mods that you can do. Making that cap smaller will shift it up, and making it larger will shift it down.

News:

GCB-95 mods?

Doug_H