Wah FAQs & trouble shoot (Jim Dunlop)

from Jim Dunlop site

To understand the differences between the different wah wah pedals, it’s important to understand how the wah works. The wah wah pedal selects a portion of your sound, filters it and then accentuates it. The rest of the sound is reduced. Technicians refer to this concept as the bandpass filter.When you move the rocker up and down, the rocker turns the potentiometer. The potentiometer accentuates a tiny portion of the sound within the range that has been selected. When you put the toe down, your higher frequencies are accentuated. When you put the heel down, your lower frequencies are accentuated. When the rocker is moved up and down, you move between the lower and higher frequencies within the range you have selected.
When people talk about wah pedals, they’re talking about the Crybaby. This is the one that created some of the most timeless sound in rock.GCB95F Crybaby Classic Wah Wah
The GCB-95F comes loaded with the legendary Fasel inductor, which instantly gives you the sound of the classic 60s wahs that are considered the holy grail of wah tone.535Q Crybaby Multi-Wah
The 535Q is the answer to every guitar player’s wah dream. This pedal allows you to select from 6 different frequency range selections, ranging from the high of the Original Crybaby to the low of the Bass Crybaby, and comes loaded with the legendary Fasel inductor.95Q Crybaby Wah Wah
We’ve taken the original Crybaby and added three of our most popular upgrades: the famous “Q” control; Volume boost for up to 15dB of added gain; and our auto return function that automatically engages the effect when you place your foot on the pedal.

ZW-45 Zakk Wylde Signature Wah
With guts that that have been finely tuned to Zakk’s specs, this wah is specially voiced to deliver extra thick and cutting tones and comes loaded with the legendary Fasel inductor.

DB01 Dimebag Signature Wah
This might be the most flexible and powerful wah pedal ever. The DB-01 has an extended sweep range with a fine tune knob, 6-way range selector, kick in volume boost, LED indicator and loaded with the legendary Fasel inductor.

105Q Crybaby Bass Wah
The 105Q selects a frequency range on the lower end to modify the bass tones that are played with the bass guitar.

GCB-80 High Gain Volume Pedal
The GCB-80 is the gold standard of volume controllers. Quiet operation and heavy-duty construction combined with a 1 million cycle taper potentiometer give a player the most delicate control ever.

EW95V Mister Crybaby Super Volume Wah
This wah has both a wah mode, with a wah similar to the Original Crybaby and a boost mode, which offers a 16dB adjustable boost.

JH1D Jimi Hendrix Wah Wah (Formerly JH-1 and JH-1B)
The JH-1 is an altered GCB95. Legend has it that before Jimi used his Crybaby pedal, he would have his tech alter it so that the frequency range selected would be at a slightly lower-pitch. This pedal has a fatter, more open sound than the GCB95.

This is a common occurrence because the inductor in the Wah pedal acts as an antenna. When you are in an area with a lot of radio frequency, the pedal can and will pick up radio stations. It is not very easy to troubleshoot and fix, because it differs so greatly due to the different signals and the varying surroundings. What may work in one region might not work in another.The first step in troubleshooting is to find out where in your rig the signal is coming from.-First check to see if it is coming in through the AC Adapter. Use the effect with a battery and see if it is coming in through the wall. If it is, discontinue the use of the AC Adapter. If this doesn’t work, then…

-Second, check to see if it is coming in through the guitar. Turn the volume of the guitar down to zero and see if you still get the radio signal. If yes, you might want to try putting a .0068-microfarad capacitor on the input jack between the tip and the shaft. (The capacitor can be a ceramic or polyester type and voltage rating of any size works.) This will also kill the high end of your sound. If this doesn’t work, then…

-Third, check the inductor. If you have a metal inductor, you can purchase a shield from us and place it over the inductor with a ground wire that is placed under one of the screws on the PC Board. This acts as both an AC Hum and RF shield. (It is part number ECB99 – and lists for $12.00) If this doesn’t work then…

-Fourth, open up the pedal and unsolder the black wire from the pot. Slide some Ferrite beads onto the wire and re-solder it. The size, number and shape of the beads depends upon the signal that you are getting, and we have not found any rhyme or reason as to which beads work with which signals. If this doesn’t work then…

-Fifth, wrap the entire wire harness in Mumetal foil, which comes in a tape format, and hope that that works, because after that who knows!

Getting radio stations on your wah pedal is unfortunately the nature of the beast and has been since its inception. In some areas it is worse than others. It is especially bad in the Great Lakes region because the lakes act as large antennas sending out the radio signals to all areas – and all wah pedals.

The following pedals have a Red Fasel inductor: GCB95, GCB95F, 535Q, 95Q, DCR2SR, BG95, SW95, DB01, and the ZW45. The MC404 has both the Yellow and Red Fasel conductors.

The circuitry is designed for 100k pots, so using a pot of any other value will reduce the frequency range. Will this make your wah sound different? Sure. Is that kind of difference desirable? Probably not.

The instructions for replacing the potentiometer are as follows:
1. Remove the bottom plate of the pedal.
2. Loosen the screw holding the cable clamp.
3. Rotate cable clamp and disengage rack from gear.
4. Remove wires for the old pot.
5. Connect wires to ECB24B as show. (NO PHOTO)
6. Remove old pot with ½” open-end wrench.
7. Depress toe of pedal to make contact with switch.
8. Rotate new pot gear counter-clockwise to stop.
9. Install new pot in cradle and tighten.
10. Engage rack gear and pot gear, back off one tooth from stop.
11. Rotate cable clamp into rack holding position.
12. Tighten screw.
13. Replace bottom plate.

Our potentiometers are sealed to keep dirt, grime, and grease out of the pot. The scratching you are hearing is due to wear and not due to dirt in the pot. If you have a scratchy pot, you will need to replace it. If you have an ECB24 (the pot with the silver, round head), you may want to replace it with an ECB2424B (rectangular pot). We have been using the ECB24B regularly now for more than 10 years, and have found that it lasts at least twice as long as the ECB24 and sounds exactly the same. If your pot is scratchy, we recommend replacing it with the ECB24B potentiometer.

Over a period of time, the grease put on the pot can wear off (or become rubbed off through tinkering), and this can cause a mechanical squeaking noise to occur. Another cause of this problem can be that the flat spring in the rear of the pedal needs lubrication or loosening. We recommend using a generic grease to remedy these problems. Apply a small amount on the pot teeth, and for the flat spring, try putting some on the knurled pin (which drives horizontally through the pedal) where it is overlapped by the flat spring. Be sure never to use WD-40© or similar products, as these products tend to attract dust and do not last as long as grease.

There are two different AC adapters used on our wah pedals: the ECB-02 and the ECB-03. If your pedal has a female AC jack, it requires the ECB-02 (a 3.5mm plug); if the AC jack has a pin in the center of it, it requires the ECB-03 (a 5.5/2.1mm coax plug). Any versions of our wah pedals that support AC adapters require the following power parameters: anything greater than 20ma, 9volt. The ECB-02 is positive tip polarity, and the ECB-03 is positive outside polarity.

This typically occurs when the inductor (also known as the coil) on the pc-board becomes defective. Usually this is from dropping the pedal or trying to do a modification to the pedal and the drill goes a little too far. The inductor can be found near the center of the pc-board and is the largest component on the board (except for the input and output jack on later revisions). You can determine if the inductor is bad by measuring the resistance across the 33Kohm resistor (orange/orange/gold); if you measure 100 ohm or higher, the inductor is definitely open (i.e. bad). For you tech types, the inductor is in parallel with this resistor – thus the reasoning behind measuring the resistor.

We sell every part that comprises our current revision GCB-95 pedals, down to the transistors, grommets, etc. For older pedals, we still have many parts available, but older pc-boards are no longer stocked and are difficult to obtain. To check which parts are available and how much they cost, visit our Parts Pages. If you have further questions, please email us at customerservice@jimdunlop.com.

All  pedals should only be powered with the recommended voltage.

Please refer to our ‘True Bypass’ article on our Dunlop Blog for an up-to-date list of our pedals which contain true bypass.

Check to ensure that your adapter or battery have the correct voltage and/or polarity. Ensure that both cables are plugged into the correct input/output jacks.

There is a possible impedance mismatch with other pedals in your effects loop. Isolate and remove the pedal from the loop to see if this still occurs.

It depends on which pedal and how it has failed. Please contact our Technical Support Department as this is a case by case matter.