The Alesis Andromeda A6 has spent twenty-six years as one of the great unclonable synths. Sixteen voices of genuine analogue, two oscillators and two filters per voice, and a control architecture more like a modular system than a preset machine — all of it hanging off custom ASICs that nobody has been able to source or substitute since production ended.

Isla Electronics has now previewed ASICS, which appears to be the first serious attempt at emulating it.

Modelling the Chips, Not the Sound

The name is a hint at the approach. Brad Holland, the developer behind Isla's Caladan hybrid polysynth, has said he modelled the Andromeda's custom ASICs directly, alongside the Moog 921B-style oscillator circuit, the SEM state-variable filter and the Moog ladder filter — the two filter topologies the A6 famously provides per voice.

That is a very different exercise from sampling an instrument or approximating its character with generic building blocks. Circuit-level modelling is slow, expensive in CPU terms, and difficult to get right, but it is the only method that reproduces how a synth behaves at the edges: what happens when you overdrive the ladder, how the SEM's notch behaves under modulation, how the oscillators interact when hard-synced.

For an instrument whose reputation rests almost entirely on the density and complexity of its raw voice, that choice looks like the right one.

It Also Talks to the Hardware

The detail that has drawn the most attention is that ASICS is fully SysEx-compatible with the original machine and can act as a remote controller for it. Holland has confirmed the plugin can function as an editor for A6 hardware.

Andromeda owners will understand why that matters. The A6 has an enormous modulation matrix and a front panel that, while unusually generous, still buries a great deal behind menu diving. A full-screen editor that speaks the instrument's own SysEx dialect — and that happens to also be a working emulation of it — is a genuinely useful pairing. Patch libraries can move between the plugin and the hardware in both directions.

The Expression Question

The Andromeda occupies an interesting position in expressive-playing history. Its own keybed does not transmit polyphonic aftertouch, but the instrument's voice architecture — sixteen fully independent analogue voices, each with its own filters, envelopes and LFOs — is exactly the kind of structure that responds well to per-note control. Players have long driven A6 hardware from external controllers to exploit that, and the synth is capable of receiving polyphonic aftertouch to address voices individually.

An emulation removes the hardware constraint entirely. In software, sixteen independent voices with independent modulation is simply a voice-allocation decision, and per-note pitch, pressure and timbre routing becomes a question of what the developer chooses to expose.

Isla has not announced MPE support, and nothing in the previews confirms it. We are flagging the architecture, not the feature list. If ASICS ships with per-note expression routing into that modulation matrix, it would be one of the more compelling MPE targets to arrive in a while — a large, genuinely complex analogue-modelled voice with somewhere for every expression dimension to go. If it does not, it remains a faithful reconstruction of a synth that was never designed around MPE in the first place.

Anyone considering it specifically for expressive playing should wait for the released specification rather than assume.

Where It Came From

ASICS grew out of Isla's work on the Caladan, a multi-timbral hybrid polysynth with expansion cards that entered pre-production earlier this year. The Andromeda model was originally developed as one of the digital engines for that instrument.

Public reaction to the demos was strong enough that Holland decided to release it separately as a VST/AU plugin as well. He has described it as almost feature-complete, with polish work remaining.

What We Know and Don't

Confirmed: circuit-level modelling of the ASICs, 921B oscillator, SEM SVF and Moog ladder; SysEx compatibility and hardware editor functionality; a plugin release in VST/AU format.

Not confirmed: price, release date, platform support beyond macOS and Windows, voice count in the plugin, CPU requirements, and — as noted — any MPE or per-note expression handling.

For a synth that has resisted emulation for a quarter of a century, "coming soon" from a developer who has already shipped working analogue-modelled hardware is a more credible position than most. We will cover the release when specifications are published.

More information: Isla Instruments

Sources: Synth Anatomy, Synthtopia