SIEL DK80 with Expander in Original Box

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"A RARE SYNTH FROM THE '80'S NEW IN BOX....

JUST UNPACKED FOR PHOTO.

COMPLETE WITH PS80 POWER SUPPLY AND EXPANDER!

ALSO, DK-70 STAGE SET, WHICH CAN BE USED WITH THE DK-80.

ALL NEW IN BOX EXCEPT THE POWER SUPPLY, WHICH IS LIKE NEW!

RARE OPPORTUNITY!!!

You are bidding on a rare and complete DK desktop system by SIEL from 1985! It includes the DK 80, Expander 80, power supply and ultra rare and hard to find RAM Cartridge! This thing sounds unique and incredible. Nice Italo Brass and synth sounds. Don't miss out on this unique opportunity!!


The SIEL DK 80 is a nice mid-level synth from 1985. It features:
- 8 voices
- Double sound generation
- Advanced MIDI functions
- 87 programmable parameters
- Up to 150 programs on line
- 2-track real time polyphonic MIDI sequencer.
The "sonic character" of the DK 80 is very nice and interesting, and it's a classic "hybrid" with DCOs and VCFs/VCAs. Still, it's capable of very powerful and "fat & gluey" sounds.
The DK 80 can also have an optional pedalboard, called "PD 80" which features two pedals: the one on the left is programmable, and the one on the right is dedicated to Sustain. A great setting for the left pedal is to "scroll" the patch programs, because - in pure mid-80s style - one needs to select the program with the keypad and then press "Enter". With the left pedal, it's much quicker to go through the programs to play / check them out. It's also great for live use.
The left pedal can be assigned to:
- Start/Stop of the sequencer,
- Program Up
- Key Data To MIDI

The Italian company Siel released their DK80 synth keyboard version 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 definately 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 conatins a top octave generator with octave dividers, 5 footage outputs under VCA control, this is organ frequency divider technology rather thna synth voltage control technology, though it still remains analogue voice generation.

The Expander 80 block diagram:

OK - the Expander 80 shares with the likes of the Korg Mono/Poly, Poly 800, EX800 and also the Moog Opus 3 (so it's not alone) - it only has one VCF. If playing single notes (monophonic playing) no issue, if playing block chord stabs - no issue, but trying to play two hands at once will mean either notes not sounding again, or all notes retriggering with each new note played. The Expander 80 has a trigger mode for the user to decide which mode is best. There are some sounds when this retriggering effect can become a useful part of the sound, so it is not always a limitation!"