Siel DK80

" polysynth based on M112b structure with SSM filter and sequencer. Module version with less voices polyphony is EX80.

Overview

OVERVIEW Synthesizer 61 velocity sensitive keys main panel features a segment display, 24 buttons 2 knobs and a modulation wheel.

TERMINAL CONNECTORS:
- stereo output (mainly for chorus effect)
- sequencer clock input
- headphones out
- Midi interface
- pedalswitch input (assignable to LFO retrig, sequencer start/stop or patch UP)

VOICE machine handles 12 voices polyphony type DCO based on a custom SGS IC M112B1 which is also the VCA + SSM2031. The internal voices that can be played together or layered as a pair of 6 oscillators or even in split mode these are divided in PART1 and PART2 .
The oscillator is digitally controlled DCO which basically features 2 shapes:
- Square with 3 summable harmonics (each has individual gain)
- Square at 16' / 8 ' / 4 '
- Sawtooth

Filter, LFO and Envelope

FILTER paraphonic resonant filter based on a single SSM2045 at 4-poles slopes with keytracking option.
This IC can be found also on other italo- machine like Solton Project 100 or famous milestone like EMU Emulator II or some Fairlight CMI versions.

ENVELOPE 2 EGs (A.D.B.S.S.R. stands for: attack, decay, break-point, slope, sustain and release )

- EG 1 voice A.D.B.S.S.R

- EG 2 filter A.D.B.S.S.R

LFO up to 2 delayed modulators range from 0,25 Hz to 10 Hz and 2 destinations:

- LFO1 DCO pitch

- LFO2 VCF cutoff

Sequencer, effects and editor

SEQUENCER manages up to 2 tracks with no special functions but an internal Metronome.
Sequencer clock can be synched to either:
- analog trigger input
- digital Midi clock

EFFECTS just one analog chorus based on BBD TDA1022P with no possible edit; Chorus is not available when using WHOLE DCO detune.
Other machine with TDA 1022 chorus: Elka Synthex / Siel Cruise / Orla DSE24 / Elka Omb5.

EDITOR Just a few editors are available:
- Midiquest DK80 editor (pc/mac)
- GD80 for Commodore 64, absolutely no info but this pic:

Memory, OS and Midi

MEMORY ROM 40 sounds+ RAM 10 sounds +RAM 300 notes
RAM can be expanded using special cartridge RAM PACK which adds 50 slots.

Battery replacement: soldered CR-2032 battery 3V

OS 4OS is burnt on a single EPROM TMS2564-45JL * DOWNLOAD LATEST BIN *

MAINTENANCE common issues is the power supply model PS-80 weird 16 V AC with 500 mA and custom pinout - be sure to get this one before buying one unit!

MIDI all parameters can be controller by Midi control change:

SIEL EX80 Technical Data

Company: Siel
Model: Dk80
Class: Analog synthesizer 61 keys
Dates: 1985
Country: Italy

Display: 7 segments
Technology: analog
Synthesis: subtractive
Oscillators: 8 DCO
Polyphony: 4/8 voices
Multitimbric: 1 part

Filter: LPF paraphonic
LFO: 2 modulators
Envelope: 2 Egs
Sequencer: 2 tracks
SYNC: Midi clock / trigger
Effect: analog chorus
Midi: IN / OUT / TRHU

Memory: 10 slots
Storage: RAM cartridge
DCO IC: SGS M112B1
Filter IC: SSM 2045
FX IC: BBD 1022P / SSM2031

PSU: 16V AC- AC
WEIGHT:
DIMENSIONS: