SIEL DK 80 Expander (Mint w/Original Box) + Rare PS80 Power Supply

This Siel EX-80 can be used to expand a DK-80, or as a stand alone desktop synthesizer.
It is actually New In Original Box, as I had lost the original power supply decades ago, and it requires a special fitted power supply.  Just last year while traveling Italy in a music shop, I found another PS-80 power supply, and it is used item, unlike the EX-80, which is brand new.  I listed this as near mint, because the box was opened, and the unit was plugged in to see if all the parameters operate, which it does. 

Siel released their DK80 synth keyboard in 1985, which was a 12 voice analogue bitimbric (2 sounds at once) synth. The Expander 80 was also released at the same time being essentially (but not just) half a DK80 - 8 voice polyphonic and one sound at a time. Originally the Expander 80 was not supplied with a power supply, as the DK80 one was designed to drive the pair (Siel expected the DK80 owner to be the typcial owner of the Expander 80). The Expander 80 still retained the 300 event two track sequencer, although both tracks have to play the same sound. Similarities to the Korg EX800 cannot be ignored, especially as the voice architecture and front panel layout do have similarities. The Korg EX800 was released a year earlier in 1984, so the Siel Expander 80 definitely followed it. Internally, they share no common electronics - so it's no surprise they sound different

The Expander 80 architecture has 8 digitally controlled oscillators (DCO), 9 VCA's (8 for the DCO's and one for the noise generator) and a single 4-pole (24dB/octave) VCF (SSM2045), with nine 6-parameter digital envelope generators (8 for the VCA's and one for the single VCF) plus 2 LFOs. A pink noise generator and analogue chorus are also included. A double mode, stacks 2 DCO's together (4 note polyphonic) with detune - though the DCO's have to share the same settings. In fact the oscillators and VCA's are all on one chip (an M112 polyphonic sound generator), and the envelopes are under microproccesor control (a Texas TMS7000 in case you were wondering). The chorus is an analogue bucket brigade delay line (TDA1022).

The M112 chip contains a top octave generator with octave dividers, 5 footage outputs under VCA control, this is organ frequency divider technology rather than synth voltage control technology, though it still remains analogue voice generation.

The oscillators/VCA's are the M112 chip, as this chip was designed for use in organs like Crumar, but the SSM filter is the SSM2045 as used in the Emu Emulator II, and SSM filters (mainly the SSM 2044) are used in the Fairlight CMI II, Korg Poly-6/Monopoly, PPG Wave 2.2/2.3, Kawai K3/SC240 and Simmons SDS5 etc. The early Sequential Prophet V's used SSM 2040's as well as the RSF Kobol.

The oscillators and filters are truly amazing!   Find out for yourself, be the proud owner of an unused EX-80 and expand your music parameters!