Scans of my ratty Acxel brochure. There are low resolution scans and high resolution scans.
The Technos Acxel Resynthesizer is an additive synth developed in Quebec, Canada during the late 1980s. Like all additive synths (such as the Kawai K5000/K5, the Kurzweil K150FS, the DK Synergy/Crumar GDS and so on) its architecture is based on lots of sine-wave oscillators. These oscillators are each assigned amplitude and pitch envelopes and form the component harmonics of a sound. They are then mixed to create the resulting composite whole.
At the time the major innovation of the Acxel was, according to Technos, resynthesis. The idea is to sample a sound and extract its harmonic content using the Acxelizer, presumably using FFTs. This information is then used to assign parameters, including envelopes, to the oscillators. The hope is that this will produce something close to the original sound and will allow precise editing of the harmonic content. In practice it comes close, and when it misses the results are usually interesting.
The Acxel comes in two pieces: the Solitary and the Grapher. The Solitary contains the main guts of the machine, including the main CPU board, the oscillator boards, the sampling board, the Acxelizer board, the floppy drive, and the I/O. Each oscillator board contains 256 synthesis cells, which we shall meet presently. Connectors are provided for MIDI In/Out/Thru (although as far as I can tell the MIDI Out isn't used), the sound input to the Acxelizer as a balanced XLR, and an unbalanced phono that replicates the Acxelizer's input for monitoring. My machine is equipped with the individual output option, providing eight individual outputs as well as a "Mix" out, each on balanced XLR as well as unbalanced phono. Apparently machines were also available with only a single output-a sensible choice for the buyer as the software/hardware combination that I have lacks support for the multiple outputs. The tour of the back panel finishes with a DIN connector for the Grapher, the power socket, and a massive fan. The front of the Solitary contains only a red power button, the floppy drive (3.5", double-density) and thumbscrews for opening the case. My solitary came with rack ears; it looks as though it would span about twelve spaces. You may wish to check out a photo tour of the Solitary.
The Grapher is the machine's user interface and is what Technos flaunted in all of its ads. It's an arresting device, consisting of a vacuum-fluorescent display for status information and menus and a surface of touch-sensitive (capacitance-driven, I believe) nodules, 2114 of which contain LEDs. Yes, that's correct: over two thousand LEDs. The main array, the matrix, is 64 units across by 32 high. It is used to adjust spectra, envelopes, and waveforms. Above this is a row of 32 nodules which represent loop points; it is also used as a crude alphabetic keyboard when naming patches. Below the matrix is another row of 32 nodules that is used for selecting what elements of the synthesis architecture to enable or to select the current object to work with. These have a similar function to the four "layer" buttons on the JD-800.
On either side of the matrix are columns of nodules used to select the data the matrix displays, the operation mode, loading and saving of sounds, and so on. These will be described in more detail in a later revision of this page.
The central element of the Acxel's architecture is the ISC which stands rather pretentiously for Intelligent Synthesis Cell. Each ISC comprises: