GCB-95 mods?

moeburn · August 22, 2005, 05:16:59 PM

Quote from: Paul Marossy
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.

Yeah, how do I shift it up and down at the same time? I want to widen it.

Paul Marossy · August 22, 2005, 05:20:17 PM

Quote from: moeburn
Quote from: Paul Marossy
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.

Yeah, how do I shift it up and down at the same time? I want to widen it.

I need to answer that with another question: are you sure that your pot is adjusted properly? It almost sounds like your pot rotation is off - meaning it's in the region where it doesn't do much...

moeburn · August 22, 2005, 07:11:18 PM

Sorry about all that guys, I was testing this on my crappy amp for some reason. Of course it sounds flat, that amp cant DO bass.

I played it through my two-footer amp and it sounds farking awesome. Thanks for all your help guys! I'm gonna get a rotary switch for 0.068uF to 0.008uF, install true bypass, a pot on the inductor's resistor, and maybe even a fasel.

Paul Marossy · August 22, 2005, 07:21:08 PM

Quote from: moeburnSorry about all that guys, I was testing this on my crappy amp for some reason. Of course it sounds flat, that amp cant DO bass.

I played it through my two-footer amp and it sounds farking awesome. Thanks for all your help guys! I'm gonna get a rotary switch for 0.068uF to 0.008uF, install true bypass, a pot on the inductor's resistor, and maybe even a fasel.

Cool.

moeburn · August 22, 2005, 07:53:53 PM

I was reading "The Technology of Wah Pedals" in the section of why the Fasel inductor was better than stock inductors, and I read this:

QuoteWe came to the conclusion that the only way this could happen was if the inductor core had some kind of magnetic offset in it, so one polarity of the waveform saturated earlier than the other.

He suggested that in order to induce a magnetic offset, you would have to put another inductor around it and feed current through it.

I have a huge collection of neodymium magnets, I'm wondering if stacking them on top of the inductor to induce the magnetic offset will have the same effect. I'm gonna open it up and try it out.

Paul Marossy · August 23, 2005, 10:43:35 AM

I have heard of people using refrigerator magnets in a similar fashion. I'm not sure that it really does anything, though.

moeburn · August 23, 2005, 11:42:29 AM

No, it didnt really do anything.

Paul Marossy · August 23, 2005, 12:01:39 PM

Quote from: moeburnNo, it didnt really do anything.

Those are pretty weak magnets. Your experiments may yield better results... :wink:

nooneknows · August 23, 2005, 12:23:54 PM

If you don't want to use a dpdt switch but you still hate highloss, try to substitute the input bjt of the stock pedal to a jfet, pulling out the useless resistor and putting a 1M or a 2.2M R from the gate to ground.
This raises the input impedance to 1M circa, high enough to limit high-end losses, mine works fine this way.
ciao,
M.

moeburn · August 23, 2005, 06:09:33 PM

Ok there are a couple more mods I want to do, but I'm not really sure how to do them. I have a spare "x-wing" DPDT switch, how can I mod the crybaby to use it as true bypass with an LED? I dont really want to solder extra wires to the board, since that makes it much more difficult to remove the board for extra mods.

I also want to put a power switch on it, since all my pedals have that (I hate unplugging 6 cables when I'm done playing). Any suggestions for location?

Paul Marossy · August 23, 2005, 06:20:23 PM

Quote from: moeburnOk there are a couple more mods I want to do, but I'm not really sure how to do them. I have a spare "x-wing" DPDT switch, how can I mod the crybaby to use it? I dont really want to solder extra wires to the board, since that makes it much more difficult to remove the board for extra mods.

Check out this page: http://www.diyguitarist.com/PDF_Files/WahTrueBypass.pdf
It's a really simple mod. You may want to tweak the input resistor a little after the mod by doing the following: "replace the 68K series input resistor with a lower value, say 47K. This gives a slight increase in volume. Too low a value is likely to result in the pedal picking up radio interference. This can be addressed by adding small value (10 - 20pF) capacitors between the collector and base of each transistor." (from http://homepage.ntlworld.com/s.castledine/greenfuz/wah.html)

moeburn · August 24, 2005, 11:05:19 AM

Its two days after I got the wah and its already making scratching noises when i play it. I dont really want to shell out $50 CAD for a new pot. But it appears its only scratching when I plug it into my computer. On my amp its fine. Whats the deal?

Paul Marossy · August 24, 2005, 11:32:16 AM

Quote from: moeburnIts two days after I got the wah and its already making scratching noises when i play it. I dont really want to shell out $50 CAD for a new pot. But it appears its only scratching when I plug it into my computer. On my amp its fine. Whats the deal?

Some DC from the wah must be appearing at the input of your soundcard. If you put a 0.01uF cap (or maybe an FET buffer) between the input of your sound card and the wah pedal, it will most likely stop doing that. Not sure how it would affect the tone, though.

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