Circuit Bending

My circuit bending research focuses on exploring different approaches to adding external control mechanisms to found circuitry. This post provides information about a sampling of controllers designed to control circuit bent instruments in performance as well as installation settings. A few select circuit bent instruments and toys are also briefly presented.


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The Toys interface is an ongoing exploration in controlling circuit bent toys and instruments with Arduino powered interfaces. Toys was shown as an interactive sound installation at the 2014 Digital Arts Expo at the California Institute of the Arts. The interface controlled 4 Farmer Says toys, a robotic talking bear, and three keyboards. The interface is powered by an Arduino Mega and can be either powered by battery or USB. It functions both as a controller for hacked electronic devices as well as a tool for hardware hacking and circuit probing/bending. It is designed specifically for interfacing with low voltage DC circuits and can’t handle anything with a high voltage or high current. The first eight output channels feature PWM, each channel has its own pot to control the pulse width and a single pole switch to disconnect the output. These outputs are also effected by a master delay pot stationed in the upper left corner of the interface. The master delay sets the length of a timer that periodically reconnects the outputs. This is effective for simulating switch or toggle conditions in bent circuits and is necessary for getting many instruments to reach incantation.The next five outputs are effectively the same as the first eight with the noticeable exception that they have no feedback LEDS, no on/off switches, are not effected by the reset timer, and are arranged on the interface in a separate group. In the rear, all 13 outputs are accessible via RCA connectors. The ring corresponds to common ground while the internal pin is the signal. There is one additional RCA connecter in which both the ring and pin are connected to ground, allowing for easier probing and bending. The front of the interface has a built in ultra-sonic rangefinder which allows the unit to be aware of someones presence. When the installation is idol, it remains off for just under a minute before pulsing all its channels; calling for interactees. It continues repeating this cycle until someone approaches and activates its ‘active’ state.

Here is a short video demo of the Toys interface in action.

Cat Keyboard

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I started working with the Cat Keyboard in February 2014. This wonderful toy has the functionality of any other good toy keyboard with several notable additions. Firstly, it has a Meow setting; which is awesome. It also has a microphone that you with amplification and recording capabilities. It was a relatively easy circuit to work with; the design has lots of space on the inside which allowed me to maneuver easily.

As with most of my bends, the first modification was the addition of a voltage divider for controlling the clock speed of the board. Next, I added three body contact points as alternative ways to manipulate the toys clock. I proceeded to remove the shitty stick microphone and replace it with a balanced 1/4″ input jack. Naturally, I added a 1/4″ output jack for application and recording purposes.  I wired up a switch to reset the circuit by disconnecting the battery back in case of circuit failure.  Lastly, I soldered in a ‘noise’ pushbutton that introduces white noise or tone into the sound chain when pushed.

A video of the Cat Keyboard jamming with my Farmer Says can be found is below.

Bruins Guitar

The Bruins Guitar is the best example of how your source material is the number one contributing factor to the overall awesomeness of your final bend. The toy guitar stores about a dozen simple melodies and uses a score playback system to cycle through the melodies. There is a RED led on one side of the body ring that shines across the gap into an IR sensor on the other side. This crease a optical connection that, when broken, will play the next note in the score. The guitar has six timbre settings including french horn, guitar, and banjo.Bruins_Guitar_01

 The bend consisted of adding a 1/4″ output jack (just like a real guitar), a pitch pot, a reset button, and a note trigger button. The reset was needed because rarely the circuit would seize up needing a reboot. The note trigger button is so the player can more quickly trigger the device; for the IR sensor resets slowly and you drop triggers if the guitar is strummed too fast. The pitch pot is really where the magic happens, its just a simple voltage divider circuit that replaces the resistor that regulates the toys internal clock oscillator. When the instrument is down pitched it shines as a menacing noise machine. The Bruines Guitar is the highest fidelity of any of my circuit bent toys; once amplified, and integrated into a FX chain, it sounds even more wicked and unworldly.

You can watch a video demo of the Bruins Guitar below

Butterfly Phonics


While I was working on the Butterfly Phonics I had just read Handmade Electronic Music my Nicolas Collins and was pumped the effects of body capacitance. I was able to find seven points on the tiny circuit board that when touched with a dental pick while the toy was sounding produced interesting sonic results. I soldered one end of a wire to each of these points whiles the other ends were soldered to a thumb tack that were pushed through the plastic casing. Last, I added a reset switch on the front, as well as my standard 1/4″ output on the side.

My Kidz Keyboard


Although somewhat unremarkable in its technical specs the My Kidz Keyboard is one of the most functional circuit bent instruments I have created. In its first version, it had one pot for controlling the distortion level and a second pot for the pitch, or clock speed, of the board. I also added a switch for activating and deactivating the distortion all together.

While the control is quite simple, the magic of this device lies in the samples available for playback. The toy has a farmer theme and includes many barnyard animal noises as well as quite a few silly drum beats. When pitched up, the animal noises are more like instruments. When pitched down and amplified through a nice stereo system via the added 1/8″ jack, the keyboards sinister side becomes apparent as the clips begin to crackle and break.

Farmer Says Incantor

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The Farmer Says Incantor has two centers for control. The primary section is the button pad located in the middle of the instrument. The button pad is what the large plastic arrow presses as it rotates in circles. I removed the arrow and glued the pad to the front of the toy, allowing for precise control over what buttons are being pressed. The second set of controls is on the bottom front corners of the device and contains all of the glitch controls. There is a switch that disconnects the onboard speaker, another switch that turns the instrument on and off, several momentary ‘glitch’ buttons, and a volume/overdrive pot which also aids in entering into an infinite glitch state (incantation as Reed Ghazala likes to call it).

Here is a short little demo showcasing the Farmer Says See n Say in action.

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