Companion Box Recipe (Hardware Remix / Circuit Bending)

Hardware remixing is a way to re-examine the affordances of musical technologies. Companion Boxes are circuit bent DIY electronic musical instruments. The sounds they make depend on the circuit that is used. The devices I made are based on multi-effects processors by the Zoom company. This remix changes the effects from audio processor to audio generator.

It is assumed anyone following this tutorial will have knowledge / experience of how to solder. For more information on soldering; find the adafruit tutorial online.

MATERIALS

Used ZOOM multi-effects processing unit,
VHS cassette box (or other suitable enclosure),

Non-latching push switches (x2 SPDT),

A10k potentiometer,

connecting wire (recycles if possible e.g.: printer ribbon cable),

TOOLS

Screwdriver,

soldering iron & solder (30w),

wire cutter & stripper,

crocodile clips,

glue (hot glue gun or epoxy resin),

drill,

file,

craft knife,

OTHER USEFUL ITEMS

signal generator,

amplifier,

audio cables,

& to document the process: camera, notebook, pencil.

Check the effect circuit still functions. Power up the circuit. Send a signal to the input. Listen to the output using an amplifier.

Use the screwdriver to open the enclosure of the effect unit. Remove the PCB. Take care not to damage any connections (e.g.: power cables).

Identify the input and output jacks; the markings on the original enclosure are a guide. There are several points of interest: the solder pads for positive input, positive output and negative ground these three points will be connected to the lugs of the potentiometer. Another four pads are used for adding push-button switches to move through pre-set patches.

Power up the unit. Using crocodile clips; make a temporary connection from the positive input to the positive output. Connect the PCB output to an amplifier using the audio cable. An oscillating note or pattern should be audible.

Using crocodile clips, join the input pad to lug 1 of the potentiometer and lug 2 to the output pad and lug 3 to ground. Turning the potentiometer should now change the amount of feedback between the input and output. Listen to changes in the sound. The most common change is in the amount of gain or volume in the output, other novel modulations may appear.

Use crocodile clips to join the pins of the pads on the PCB attached to the switches for changing patches. Touching the ends of the clips should allow you to shuffle through pre-sets.

This step requires safe usage of hand tools (drill, file, knife, pliers).

After testing the switches and potentiometer, it is time to assemble the parts. The PCB mounted audio and power sockets can be made to fit into the spine of a VHS cassette case. Put the PCB in place and mark where holes can be made on the enclosure.

Drill small holes. Carefully make the holes large enough to accommodate the PCB mounted components (audio and power sockets). Check alignment as you go.

Plan where the new controls (potentiometer and push switches) will work best. Ensure there is enough space for them in the enclosure, without interfering with the PCB. Drill holes and mount the new hardware.

Measure & cut wire to connect the new components to the PCB. Strip & tin the wires. Connect the potentiometer using the solder & iron. Put the potentiometer in the hole you prepared and use the pliers to tighten the nut to hold it in place.

Put the push switiches into place and fasten in place using pliers. When they are secure, solder the two lugs of the switch to the two lugs on the PCB.

Make music using your new feedback instrument.

The aim of the player is to listen and learn what the instrument is capable of & how it might fit into a performane. Players are expected to learn what their instrument can and cannot do by approaching the instrument with an intention to listen & judge its output whilst investigating th affordances of the minimal control interface.

The sounds made will rely on the pre-sets stored on the device, the amount of feedback between input and output and connections between components on the PCB.

The minimal interface of the instrument can be expanded to increase the amount of timbres available to a performer by making connections from legs of the RAM chip to external connections on the interface. Increasing the number of nodes connecting the inside to the outside, increases configurations available to a performer and the chances of creating new tones and sound behaviors.

If this guide is followed and th maker uses the device to record a performance; please share the sounds:

toneburstrecs at gmail dot com