This instrument is inspired by a thumb piano, a bass guitar and the Rhodes and Wurlitzer Electric Pianos in it's aesthetics and electrical design. Made for a university course in which we were tasked at making an original instrument, it was made to create strange percussive hits and low rumbles and thus is more a sound design tool than a classic instrument.
The steps in this guide were written to replicate the layout and aesthetics of this particular design but obviously, get creative and do what you like with this basic principle.
Step 1: Required Materials and Tools
1 x bass guitar pickup
1 x bass guitar bridge
1 x 1/4" TS output terminal
4x cut lengths of bass guitar strings (length = 12cm)
1x potentiometer (5K algorithmic)
1x circular metal disc from plunger
1x knob for potentiometer
1 x 30cms of wire
1 x chopping board (30cm x 20cm x 1cm
1 x block of soft wood (5cm x 7cm x 5cm)
1 x round piece of soft wood (diameter = 10cm, height = 1cm)
2 x cylindrical pieces of soft wood (18cm x 2cm x 2cm)
18 x screws of various sizes
4 x springs
1 x 9cm cut length of generic plastic folder spine
1x cut length of foam (9cm x 1.5cm x 1cm)
Tip - most necessary components can be found by taking apart a bass guitar (pickup, bridge, potentiometer, strings, springs, output jack terminal and some screws)
Electric Drill with drill bits to match screws
A variety of screwdrivers to match screws
Step 2: Putting It All Together
This is a very easy procedure for anyone versed in woodwork however, a step by step guide is shown below.
Firstly, screw the two cylindrical pieces of soft wood onto the bottom so that the board sits off the ground. This ensures that the 1/4" TS output terminal and the wiring won't be disturbed when placed onto a surface.
Attach the pickup and the block of soft wood together and onto the board with drilled guide holes and a screwdriver. I used two on the bottom to securely attach it to the board and four onto the side in the correct placements for the pickup to be attached. Drill a hole down to underneath the chopping board for the pickup's wire to lead.
Note - Springs placed onto extra long screws in between the block of wood and pickup enable you to move the pickup back and forth along the board. This means you can alter the placement of the pickup after everything has been permanently placed down.
Next, attach the bridge, the round piece of soft wood, the cut length of foam and the cut length of generic folder spine together. There are only two screws attaching all these pieces together, as shown in the images, and appropriate guide holes should be drilled in the right places for all components. Place the four bass strings, cut to length, into the bridge and tape them down on the back. Place the piece of foam and the folder spine on top of the strings on the bridge, shown in the images. Screw together and onto the board ensuring that the strings are 5mm away from the pickup.
Drill a large hole for the potentiometer to poke through to the top of the chopping board and screw it into the circular metal disc. Screw the disc to the board and attach a the knob to the end of the the potentiometer.
Lastly, drill the 1/4" TS output terminal onto the board as shown in the image.
Step 3: Wiring
Image Credit - Seymour Duncan
The wiring for this instrument is a basic 1 pickup, 1 volume circuit similar to single pickup instruments such as some of the early Fender Telecasters but with no tone control. Following the above diagram and the image of the bottom of the chopping board in Step 3, solder the two wires leading from the pickup to the potentiometer onto the appropriate pins, and then onto the 1/4" TS output terminal. The circular metal disc attached to the top which holds the potentiometer can be used in place of the bridge for grounding. Make sure that all connections are soldered securely, everything is connected to right terminals, and grounded correctly. Don't worry, there is no danger in wiring things incorrectly as there is not enough voltage travelling through this circuit to hurt anyone.
Step 4: Play
Plug the instrument into a guitar or bass amplifier and give it a play by hitting and plucking the strings or by tapping on the various parts of the bridge.
- Use the volume control to change the attack and release of each sound.
- Experiment with different guitar pedals like delays and distortion.
- You can attach a variety of different things to the strings like springs, tape or blue tack to change the sound of each string in a similar way to a prepared piano
- Tap the strings hard so they hit the chopping board below creating a percussive sound