Elka Synthex (1981)

 

Impressive analog cult poly synthesizer designed by Italian organ societies Elka & Orla.

KEYBOARD 61 keys (no velocity) optional pair of legs.
The main panel features 36 knobs, 84 buttons, 6 levers and a joystick for pitch bending and modulation.

Back panel terminal connectors:
- tape interface
- sequencer sync input
- stereo analog out
- expression pedal input control for filter cutoff
- footswitch input program up
- footswitch input sustain + EG release
- footswitch input glide control.

 

TECH main 8 bits CPU 6502 clocked at 1MHz manages 8 voices polyphony organized on 4 voice boards with stereo mode . A synth basic Synthex patch is composed by 2 DCO oscillators + 1 white-pink noise generator.

Hear stereo mode

 

OSCILLATOR DCO1 and DCO2 can be ringomodualted and mixed with individual mixer and have similar characteristics:

octave range: 16' 8' 4' 2' 1' shapes: sawtooth / pulse (variable width) / square / triangle detune: yes Hardsynch: 2>1 Hear hardsync harp

PERFORMANCE the multiplexed boards feature 4 playmodes:

- double mode: is a layer of 2 sound patches - split assigns 2 patches on a different keyboard zones - stereo panning mode: voice boards are sequenced to left or right stereo field - polyphonic portamento with glide option and variable speed rate Hear glide

FILTER is a multimode resonant model based on 8 Curtis CEM 3320 chips.
The VCF works in 3 different modes with possible polarity inversion option:

- lowpass at -24 dB slope - bandpass at -12 or 6 dB slope - highpass at -12 dB slope.

Hear filter sweeps




LFO there are 2 LFO, a main one (LFO1) and a simpler one (LFO2) triggered by joystick that modulates onlu pitch and filter with a triangle shape. LFO1 is quite complet:

shape: triangle /saw/ ramp / square destinations: pitch / width / amplitude delay: yes depth: yes Hear Insane LFO

ENVELOPE 2 EGs:

- EG1 VCF 4 segments ADSR - EG2 AMP 4 segments ADSR. In addtion 2 extra functions for envelope control: hold and sustain.

SEQUENCER a 4 tracks recorder with real-time or step entry notes.

Each track transmits Midi signals, then whole sequence can be shifted in real-time for performance. Recording function are limited to 5 buttons and 2 knobs: write, beats, delete, loop mode, ready-reset, gate EG value.

SYNC internal frequency or slave-tempo mode controlled by external + trigger pulses.

EFFECT based on TDA1022 is a 3-modes analog chorus fixed rate and depth values.

Hear Chorus modes

MAINTENANCE Synthex suffers from common issues

voice boards lifespan that is quite unpredictable, fortunately there are not so many custom IC onboard, Synthex is mainly build with TTL and common electrical parts on the shelf - maintenance requires patience and experience since there are a lot of circuits inside and a precise calibration.

MEMORY:

- 40 ROM presets - 40 RAM user slots - 128 events per track (512 total) Memory based on a 3.6V internal battery, created sounds can be saved only to tape interface - Click to enlarge pic -

 

OS on EPROM 2532 (x2) + 2516

DOWNLOAD BINARIES

MIDI second and third Synthex versions implement a simple Midi interface manage only basic note ON-OFF data.

According to Castelfidardo center there have been 1850 machines produced: - wave 1: 50 units (no Midi) - wave 2: 800 units (external Midi interface) - wave 3: 1000 units (standard Midi)

RELATED FAMILY

	The 2015 Synthex reissue failure. After a failed crowd-funding campaign named "indiegogo Bringelkaback" the Finnish company just gave up on this project- even J.M jarre made a vid to support this funding. Reality is: elka synthex will NOT be come back.
	SYNTHEX 2- "the evolution of a legend" The original italian engineer Mario Maggi is working a new digital project called "Synthex 2". READ THE SPECS from Synthex 2 website.

 

 

VST PLUGIN / SAMPLED VERSION there are some free and commercial samples set:

	Polynominal 2 sounds fully sampled at 4 octaves: bass and a kind of brass pad sound.	30 MB FREE! Free donation
	ZOOTOOK Xils-Lab Syn'X	SYNTHEX VST- Free Commercial VST plugin

GALLERY:

		Early model

 

SPECIAL AWARDS:

- technical care