Cherry Audio Elka-X Review: The Rare Synthex, Revived

May 13, 2025

The Italian Poly Almost Nobody Owned

Only around 1,850 ELKA Synthex were ever made, yet it turns up on records by Jean-Michel Jarre, Stevie Wonder and Depeche Mode's Martin Gore. That kind of rarity usually means four-figure prices and a service bill to match. Cherry Audio's Elka-X puts it in a plugin for a fraction of that.

It's not a pixel-perfect clone, and it doesn't try to be. What it gives you is the Synthex's bright, glassy character with a lot more flexibility than the original ever had.

What It Is

The Synthex was designed by Mario Maggi and launched by ELKA in 1981. It was an eight-voice, bi-timbral analogue poly with two DCOs per voice, a multimode filter and a four-track sequencer, and it was a commercial flop despite all that. Jarre used it for the laser harp sound on Rendez-Vous, which is probably its most famous moment.

Elka-X keeps that architecture and doubles the polyphony to 16 voices, which you can layer or split across the keyboard with two different patches. It runs as a plugin or standalone.

Cherry Audio Elka-X oscillator and filter section

The Sound and the Architecture

Each layer has two DCOs with triangle, saw, square and variable pulse, plus white or pink noise. Ring modulation and cross-PWM between the oscillators are where the Synthex gets its bell and chime tones, and they're well worth exploring. The filter is a CEM3320-style multimode with 12 or 24dB lowpass, 6 or 12dB bandpass and 12dB highpass, followed by ADSR envelopes for filter and amp.

The character is bright and clean rather than fat and woolly. Pads shimmer, brass is crisp, and with the chorus on it has that wide, slightly glossy early-80s sheen. 4x oversampling keeps the top end clear. In a mix it sits above the low mids rather than piling into them, so it layers well with a warmer synth underneath.

What It's Good At

The layering is the star. Put a pad on one layer and an arpeggiated pluck on the other, pan them apart and you've got a finished part from one instance. Each layer has its own echo and reverb settings, and the reverb uses Cherry Audio's Galactic algorithm, which goes properly huge when you want it to.

The sequencer has been expanded to four monophonic tracks of up to 128 steps each, assignable to either layer and saved with the preset. Tracks can run at different lengths, so they drift against each other, which is great fun for Berlin-school and Jarre-style sequences. There's an arpeggiator that can be assigned to either layer too, plus chord memory, unison with detune and glide. The 600+ factory presets are strong, and quick to tweak into something of your own.

Cherry Audio Elka-X effects and layer controls

Where It Falls Short

The voices can sound too uniform. Sound On Sound's review noted that identically tuned voices lack the slight variation you'd get from analogue hardware, and there's no "analogue drift" control to dial some in. The arpeggiator and sequencer also send every note at full velocity, so velocity-sensitive filter patches can come out louder and brighter than you'd expect, and the output limiter will distort if you push it.

The oversampling isn't light on CPU either, especially at high sample rates with small buffers. Stack a few instances and you'll want to bounce some to audio. And unlike several of Cherry Audio's synths, there's no MPE.

Living With It

A quick word on programming. The panel follows the original closely, so it's laid out logically from oscillators to filter to envelopes, and Cherry Audio's Focus zoom helps on a smaller screen. Everything is MIDI mappable with MIDI learn, so if you've got a controller with plenty of knobs, it's a pleasure to tweak by hand rather than by mouse.

Who It's For

Synthwave, retro electronica and soundtrack work, and anyone chasing that early-80s Jarre sound. It's a good second poly if you already own something warmer like a Jupiter or Prophet emulation, because it covers the bright, glassy end those don't. If you only need one synth for everything, it's probably not the first one to buy.

Cherry Audio Elka-X step sequencer