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Elka Synthex



elka synthex

title synthex

audio demo trend price : 5000€
manual schematic demo video comments

Elka Synthex (1981)


Impressive analog polysynthesizer designed by Italian organ societies Elka & Orla.

Synthex reached the olympus of all-time cult machine polysynth.

synthesizer Elka

left board

info KEYBOARD (weight: 30 Kg) 61 keys, 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 IN
- stereo out
- expression pedal control filter cutoff
- footswitch input program up
- footswitch input sustain
- footswitch : EG release
- footswitch : glide control

synthesizer features 8 voices polyphony based on subtractive synthesis generated by 4 overlaped boards featuring 2 voices on each.

edit OSCILLATORS a voice is composed by 2 DCO + white or pink noise generator:

octave range 16' 8' 4' 2' 1' 16' 8' 4' 2' 1'
waveforms saw / pulse / square / triangle saw / pulse / square / triangle
detune yes yes
PWM yes yes
sub oscillator no no
mix volume yes yes


edit OSC SYNC:
- DCO2 can be hard-synched to DCO1
- digital ringmodulator with fixed value

the multiplexed boards features some advanced poly functions:
- double mode: is a layer of 2 sound patches
- split: assign 2 sounds on a keyboard zone
- polyphonic portamento with GLIDE option and adjustable speed rate
- stereo pan mode

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



lfo LFO there are 2 modulators:

waveforms triangle /saw/ ramp / square triangle
destination pitch / width / amplitude pitch / filter
joystick trigger no yes
depth yes yes (by joystick)
delay start yes no


adsr ENVELOPE there are 2 EG:
- EG1 VCF: 4 segments
- EG2 AMP: 4 segments
Also 2 extra functions for envelope control: HOLD and SUSTAIN.

edit SEQUENCER a 4 tracks recorder with real-time or step entry notes. Each track transmits Midi signals, then, during playback, the 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
- 2 knobs for gate EG value


seq spec

edit SYNC internal frequency or slave mode controlled by external +5V trigger pulses.

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

memroy MEMORY
- 40 ROM presets
- 40 RAM user slots
- 128 events per track (X4)
Sounds can be saved only to tape interface.

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

lfo Production Series according to Castelfidardo center there were 1850 machines produced:

- wave 1: 50 units (no Midi)
- wave 2: 800 units (external Midi box)
- wave 3: 1000 units (standard Midi)


repair synthexMAINTENANCE definitely NOT the most reliable machine in the world:

- voice boards lifespan that is quite unpredictable, fortunately enough there are not so many custom IC onboard, Synthex is mainly build with common electrical parts "on the shelf".

- maintenance requires patience and experience since there are a LOT of circuits inside.

- you should not worry too much about this aspect on the future, just be friendly with you trusted technician.

picture by Gallio

big elka synthex


cat on synthex

*Laser Harp is the preset used by Jarre. More info about this controller HERE
**Drums Sequential DRUMTRAKS
***Delay by Dynacord Pdd14
**** acid line Roland Tb303 drums+ Roland Tr909 + Vocoder SCV350

cloud sound Soudcloud Synthex DEMO

beethoven cloud2 cloud1


Paul Wiffen & The Elka Synthex Synthex Demo Sounds Synthenoxe Part 1.0
Paul Wiffen Demo Sounds Synthenoxe Part 1.0

Elka SYNTHEX - My Sounds 1 - 20 Laser Harp sound by Elka Synthex ELKA Synthex & Roland CR-78
My Sounds 1 - 20 Laser Harp sound with Roland CR-78

italian synthesizer


CHECK OUT Synthex prototype page featuring different voiceboards design.


wiseman says:

"even synthex beast need rest and repairs"
DOWNLOAD free schematics HERE.

german scan



german scan



synthex data sheet




music messe


scanning magazine


jarre synthex

laser harp
discover the LASER HARP




UVI Vintage Legends features some SYNTHEX samples but also Yamaha CS-70-20-40, Chroma, Yamaha DX1, DK Synergy and K250. AUDIO DEMO



synthesizer Elka panel slider


-Massive polyphonic sound
- Sequencer


- technical care
- basic Midi
- High price


"The Elka Synthex is one of few analog polyphonic-structured synthesizer that boasts deep bass, rich strings and complex magical electronic sound"

The elka synthex board is for review, tips and questions. Please write only in english. Trading posts are allowed, but at your own risks!



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all snapshots*, sounds, texts copyright Polynominal.com / Eric Pochesci
* overhaul picture by Riccardo Gallio: thanks! also for some demos.

elka synthex 4.5 out of 5 based on 101 ratings. price €5000