Modify Your Wah Pedal
by James Haskin in Circuits > Electronics
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Modify Your Wah Pedal
After making my talk box I started surfing the web for other guitar related things I could do myself. I found loads of info on the Dunlop GCB-95 wah pedal. This Instructable will walk you through all of the modifications I made to my wah pedal...
*True Bypass Mod
*Volume Boost Mod
*Wah-Volume Pedal Mod
*Vocal Mod
*Midrange Mod
After having completed all of these mod and a few others I recommend doing them one at a time and testing in between mods so if you don't like something, you can easily reverse it.
Your gonna need some basic soldering tools...
-good soldering iron (mines a Weller WESD51D I got for christmas)
-solder
-wire cutter/stripper
-helping hand (a must!!)
also the to wire anything to the board itself you will need 24AWG wire
*True Bypass Mod
*Volume Boost Mod
*Wah-Volume Pedal Mod
*Vocal Mod
*Midrange Mod
After having completed all of these mod and a few others I recommend doing them one at a time and testing in between mods so if you don't like something, you can easily reverse it.
Your gonna need some basic soldering tools...
-good soldering iron (mines a Weller WESD51D I got for christmas)
-solder
-wire cutter/stripper
-helping hand (a must!!)
also the to wire anything to the board itself you will need 24AWG wire
Research
I think this is a big step in all of my projects. You don't want to just jump in without input from multiple sources. A few of the site that helped me were...
http://homepage.ntlworld.com/s.castledine/greenfuz/wah.html
http://www.stinkfoot.se/andreas/diy/mods/dunlop.htm
http://www.guitarzone.com/forum/index.php?showtopic=176864
http://www.geofex.com/- click "FX Technology
-Technology of the..." in the upper left
http://www.geocities.com/overdrivespider/tb.htm
http://www.geocities.com/j4_student/schematics.htm
These are some pictures I found useful...
http://homepage.ntlworld.com/s.castledine/greenfuz/wah.html
http://www.stinkfoot.se/andreas/diy/mods/dunlop.htm
http://www.guitarzone.com/forum/index.php?showtopic=176864
http://www.geofex.com/- click "FX Technology
-Technology of the..." in the upper left
http://www.geocities.com/overdrivespider/tb.htm
http://www.geocities.com/j4_student/schematics.htm
These are some pictures I found useful...
True Bypass
So when your have you pedal off it doesn't affect your sound right? WRONG!! You may have noticed that even when off some of you effect pedals "suck" the tone from your guitar. A better explanation can be found Here.
I chose to remove the input buffer because it seemed to be the most easily reversible and from what I read, sounds better.
1. Open up the case and remove the circuit board.
2. Desolder the components.
3. Desolder the switch.
4. Install the new switch. (i used a 3PDT switch. Check out ebay for good deals)
If you use a 3PDT switch you can also add an LED to you pedal but I didn't want to.
Check It Out
I chose to remove the input buffer because it seemed to be the most easily reversible and from what I read, sounds better.
1. Open up the case and remove the circuit board.
2. Desolder the components.
3. Desolder the switch.
4. Install the new switch. (i used a 3PDT switch. Check out ebay for good deals)
If you use a 3PDT switch you can also add an LED to you pedal but I didn't want to.
Check It Out
Volume Boost
This is one of the easier mods because If you've converted to true bypass, all you need to do is replace the 68K series input resistor with a lower value. I read that too low a value is likely to result in the pedal picking up radio interference. I made the mistake of following That_Pink_Queen's model almost exactly. Luckily this is one of the ones he made that sounds good.
Wah-Volume Pedal
Now I'm sure we would all love one of these here, but if your like me you just need something that works and wont cost you your left nut. By adding a DPDT switch that disconnects the 4.7uF capacitor you can cancel the wah effect and you'll have yourself a volume pedal.
I got 50 of these babies on ebay for $10 w/shipping.
I got 50 of these babies on ebay for $10 w/shipping.
Vocal
This one is pretty cool because it allows you to treak the sound of wah itself.
"Replace the 33K resistor... with a 68K. This gives a more vocal quality to the wah. Some Vox Clyde McCoy wahs had 100K resistors here." - http://homepage.ntlworld.com/s.castledine/greenfuz/wah.html
I decided to go with That_Pink_Queen and use a 100k ohm lin variable resistor so I could dial in the sound I wanted. Or you can mess around with multiple resistors and a rotary switch. Your choice.
"Replace the 33K resistor... with a 68K. This gives a more vocal quality to the wah. Some Vox Clyde McCoy wahs had 100K resistors here." - http://homepage.ntlworld.com/s.castledine/greenfuz/wah.html
I decided to go with That_Pink_Queen and use a 100k ohm lin variable resistor so I could dial in the sound I wanted. Or you can mess around with multiple resistors and a rotary switch. Your choice.
Midrange
"Replace the 1K5 resistor... with a larger value. This increases the midrange and helps if your wah sounds dull and muted when you rock the pedal back. Try 1K8 to 2K7. Higher values than stock also smooth out the bass-treble transition." - http://homepage.ntlworld.com/s.castledine/greenfuz/wah.html
So I replace my 1.5K (1k5 same thing) resistor with a 2.2k. Sounds fine but I since I did all my soldering in one go and the removed what I didn't like I cant say weather or not the difference was noticeable. Try it out for yourself.
Tip: Save all of the components you remove and store them in a container. That way if you want to change something back... you can.
So I replace my 1.5K (1k5 same thing) resistor with a 2.2k. Sounds fine but I since I did all my soldering in one go and the removed what I didn't like I cant say weather or not the difference was noticeable. Try it out for yourself.
Tip: Save all of the components you remove and store them in a container. That way if you want to change something back... you can.