Reinhard Reisenzahn's Glitchman Turns a Sony Discman Into an Instrument of Its Own
Exploiting the anti-skip buffer of a particular portable CD player, the Glitchman project delivers something Sony never imagined.
Freelance sound engineer Reinhard Reisenzahn is making music with a classic Sony Discman portable CD player — making, not playing, thanks to a clever circuit-bending add-on for the device.
"[This is] a circuit-bending project which became part of the final thesis of my studies at the University of Art and Design Linz," Reisenzahn of the "Glitchman" project. "The reason why I decided to use a portable CD player as an object lies in the fact that, as a digital device, it emits different sounds in the event of malfunctions than an analog one. With analog devices, a medium is read, the continuous audio signal is amplified and output. A CD as a digital data carrier does not contain a continuous signal but only information consisting of 1 and 0. In the event of interference, choppy sound artifacts and short snippets (samples) of the music content can become audible. The challenge lies in creating and evoking these glitches in a targeted manner."
The target of the Glitchman project is a Sony Discman ESP2, a common portable CD player that has a feature instrumental to its conversion into an instrument: electronic skip protection (ESP), which stored audio data in a small buffer to compensate for skips caused when the player is bumped during use. "The circuit is to be manipulated before the digital-to-analog converter [DAC]," Reisenzahn explains. "The aim is to send random data stored in the buffer to the input of the DA converter at the touch of a button, which then converts it into acoustic signals and makes them audible."
The Glitchman can be used as a standard CD player, Reisenzahn explains, but the addition of new hardware provides new functionality: pushing buttons generates sound, some of which is fixed and some based on the contents of the ESP buffer — and there's a control voltage/gate (CV/gate) input for control from external devices. "If you change the CD and continue to generate interference with the buttons or via CV inputs, it is possible that sounds from the previous CD that are still in the buffer will be called up, and this can continue for several minutes," Reisenzahn notes. "This is probably due to the maximum storage capacity of the ESP buffer."
The project is documented in full on Reisenzahn's website and on Instructables, complete with printable circuit layouts for home etching.
