Traguisma – the TRAnsient GUItar State MAchine. Or, if you prefer the official title: ‘Algorithms for Combined Sound Analysis and Synthesis and their Implementation in a Multi-Processor Environment’.

This was to become a ‘Diplom-Informatiker’, my graduation project. In short it was about improving guitar synthesizer, with a focus on the attack phases of a pluck, in particular re-plucking a string that’s already vibrating.

The intended target platform was GWIZ’ Infinity Box, but as this project was cancelled, I implemented it on CNMAT’s multi-DSP box Reson8.

Here’s the PDF


A typical hardware hacking project while working at STEIM: Jane Henry approached us with a ‘Jingle Bells’ melody-greeting-card whose almost drained battery caused it to sound like Jimi Hendrix thru Granular Synthesis. In order to make the process a little more controllable we fed it with a fresh battery combined with a pressure sensor that would reduce the supply voltage. In addition a set of mercury switches combined with a resistor ladder would create even further disturbances and interruptions. The latter was moulded into a sort of anklet, while the pressure pad would go between Jane’s toes.


A simplified way to approach the Chromasone is to call it a virtual piano, although that doesn’t tell the story by far. It is played with a pair of data gloves fitted with bending sensors that are connected to a SensorLab, which also takes care of the 3-D spatial tracking of the hands’ positions, and outputs MIDI data that feeds synthesizers and samplers. Rather than replacing the piano’s keyboard for thin air, the Chromasone provides a sort of ruler that acts as a playing reference and can be rotated & tilted to change parameter mappings. Most of the initial development was done by Bert Bongers.


COEXIS = COmpiler & Emulator for maX Incorporated SPIDER (SPIDER = SensorLab Programming Integrated Development Environment). A project from my early days at STEIM as an intern, COEXIS was the bold attempt to write a cross compiler between Max and the SensorLab’s programming language SPIDER. While the project never made it past the proof-of-concept phase, it resulted in a set of externals for dynamic object creation, i.e. self-modifying code (since Max 4.5 this has become easier with the new scripting options).


A four-channel audio converter for the NeXT cube and the ispw (i.e. the IRCAM signal processing workstation).
This started as a hack with a couple of evaluation boards and some blobs of glue logic. With help from Atau Tanaka, and the original design by CCRMA.The second version though had its own board and features analog inputs as well as AES/EBU and S/PDIF. It was designed around an FPGA (by Xilinx) to allow for easy modification in the event that other customers might want to run it off a different machine. These days, however, with tons of multi-channel soundcards available it’s hard to thrill people with quadro…


The Topophonien project marks the point at which I turned my hobby of building music-related electronics into a job. Prior to this I had mostly tinkered with various guitar effect circuits, so when Sabine Schäfer approached me in 1990 with a request if I could build her a computer controlled spatialization mixer this was a rather tall order. Starting with a small 4×8 matrix with noisy VCAs and limited control, we expanded over the years to ever bigger systems with up to 40 DSP-driven channels and realtime spatialization control.

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