How to Make a Wah Pedal for a Guitar

Wah pedals enhance and diminish the frequency range of the guitar.

The wah pedal creates an expressive and distinctive sound. Wah pedals filter signal frequencies before they pass to the amp. This creates a sweeping effect. There are two types of wah pedal: Automatic and foot-operated. Automatic wah pedals filter the frequencies in line with a predetermined set of parameters, set by dials on the pedal. Foot-operated wah pedals do the same thing, but the parameters are set by rocking the expression pedal back and forth with the foot. You can make your own wah pedal using a DIY-effects pedal kit.

Things You'll Need

• Wah pedal kit
• Soldering iron
• Screwdriver

Instructions

1. Source your parts. You can order a self-assembly wah pedal kit online. The Build Your Own Clone website lists an Envelope Filter and Fixed Wah kit. The advantage of using a kit is that it comes with all necessary components and assembly instructions. You can salvage your parts if you choose, but this will take longer and there is no guarantee that the parts will be compatible.

2. Inspect your parts. Before you begin assembling the kit, check the parts for damage. Look for cracked capacitors and resistors.

3. Read the schematic. The schematic illustrates the layout of the signal processing circuit. Refer to the schematic throughout the process, but --- before you begin --- familiarize yourself with the terms and values listed therein.

4. 

   The kit comes with a blank circuit board

   Load the circuit board. The turret board will be pre-cut. Load the resistors, capacitors, diodes and processing units as per the schematic. Typical board-mounted components clip into their turret. Once they are in place, solder them to the base of the board. Mount the sockets to the board. These sockets are where the IC chips are inserted. The IC chips are the integral signal processing components and are very important. Mount the transistor flat side down on the board.

5. Mount the circuit board in the housing. If you are building an auto-wah pedal, load the circuit board normally by soldering it down and connecting the input jack to the circuit board as per the schematic. If you are building a foot-operated wah pedal, connect the expression pedal teeth to the board potentiometer before mounting the circuit board. This enables you to adjust the potentiometer with your foot so that you can alter the filter settings.

6. Finish the enclosure. Place the top half of the enclosure onto the bottom half and screw it it shut. If you are building a foot-operated pedal, lubricate the expression pedal teeth before screwing down the enclosure.

Tips & Warnings

• Practice soldering on some scrap wire if this is your first attempt. A neat and tidy solder job is crucial to the success of this project.

• Ensure that all board-mounted parts are correctly fitted before soldering the board into the chassis.

References

• Build Your Own Clone: Envelope Filter and Fixed Wah
• Build Your Own Clone: Filter Instructions
• Build Your Own Clone: Wah
• Area 51 Tube Audio Designs: Vintage Italian Wah Kit

Resources

• Electronics Tips: Soldering Techniques