Apart from his work at EMS, Tim Orr is best known for his Powertran synthesizer kits (as published in Electronics Today International magazine) such as the Transcendent 2000. In the Electronics Today International magazine August 1979 a series of articles started on the building of a string synthesizer “String Thing” which later became available as the Transcendent DPX. The articles are included with this post (below the image of the DPX).
The Transcendent DPX by Powertran was sold as a kit from around the late 1970s until sometime in 1982 when it finally disappeared from the Powertran pricing catalog. The selling price for a complete kit in 1982 was £295; at the same time the Transcendent 2000 (mono synth) was sold as a complete kit for £165. The Powertran CEM based Polysynth complete kit (with 1 voice) was sold for £275 with up to 3 additional plug in voice kits at £42 each and £245 for the 4 voice expansion kit taking the Polysynth to 8 voices (16 CEM based Oscillators).
The Transcendent DPX was designed to be a versatile keyboard instrument with a choice of several different voices and characteristic waveform envelopes with a split keyboard and a dynamic option. Realistically, the functions of the DPX are fairly basic in comparison with other Digital Piano and String synthesizers of the time though the inside design and build was ahead of most due to the minimalist cabling required. DPX has two types of “Piano” sound (Honky and Piano) plus Strings and Brass sounds selected using multi poled switches that interlock with one another on the front panel. There is a chorus, vibrato and delay function along with tone and volume control. The keyboard is touch sensitive, the keyboard DAC is 6bit – but 61 note not 64. Output of the DPX is mono (high, low).
The DPX sound generation is based on a single master oscillator (the NE566) producing a 1000.45KHz square wave which is then digitally divided by twelve integers and then divide down further from the top octave, this gives the DPX full polyphony. The cost, restricted functionality and multiple circuit board build of the DPX meant the number of kit units sold was far less than that of the still popular “single board” Transcendent 2000 Mono Synth kit. Powertran’s other synth Kit, the Transcendent Polysynth, was also seen as far too complex for most people to build so again these also did not sell in great numbers.
The description text of the DPX is kindly reproduced from www.vintagesynth.com