Synthux Audrey III: a three-string feedback drone synth
Synthux Academy launches Audrey III, a desktop synth with three feedback string voices, stereo Feed input, MIDI and USB-C power, at $549.

Synthux Academy, a Dutch non-profit, has opened orders for Audrey III, a desktop synth built around neither classic oscillators nor samples, but three string-like feedback loops. It follows Audrey II, which had a single one. The official store lists it at $549, with shipping in December. This article is based on Synthux Academy’s product page.
Feedback synthesis instead of oscillators
Synthux describes Audrey III as “three guitar players feeding back together on huge amps”. In practice, each of the three voices is a feedback loop: a signal (here “a drop of noise”) runs through a very short delay line and loops back through filters. The loop length sets the pitch, and the amount of feedback decides whether the sound decays like a plucked string or sustains all the way into saturation. That is the principle behind Karplus-Strong synthesis, the simplest of the so-called physical modelling techniques.
The engine does not stop there. After the strings, Synthux lists a fixed chain of filters and effects:
Three voices instead of one
Going from one voice to three changes what the instrument can do: Audrey II held a single drone, while Audrey III can sustain a three-note chord and play arpeggios from a MIDI keyboard or sequencer. Three voices is still limited polyphony; the difference between polyphony and paraphony is covered in our explainer on polyphonic, paraphonic and monophonic voice counts.
A “Feed” input to make other sounds resonate
A stereo audio input sends an external source (drums, vocals, another synth) straight into the strings. The incoming signal interacts with the feedback: the strings resonate with and harmonise whatever you feed them, much like sympathetic strings.
Drone by default, triggered notes on demand
Audrey III wakes up in drone mode: the last note you let go of keeps sounding. A shortcut (hold Tap and touch the second plate from the right) turns drone off; each touch then triggers the feedback, which dies away on release. The pump, a sidechain-style rhythmic ducking effect, is built into the output amplifier and runs from a single knob, locked to the tap tempo.
Specifications
| Feature | Stated value |
|---|---|
| Engine | 3-voice feedback string synthesis |
| Effects | Stereo tape echo, reverb, pump with tap tempo |
| Controls | 8 pressure-sensitive touch plates, 12 knobs, 1 fader, Tap button |
| Connections | Audio in, headphone/line out (3.5 mm), MIDI in/out (3.5 mm TRS type A), USB MIDI, sync in/out |
| Power | USB-C, 5 V, 1.5 A (computer, charger or power bank) |
| Build | Aluminium enclosure, 205 × 121 × 42 mm, 420 g |
| Warranty | 2 years, 30-day returns |
In the box: the instrument, a USB-C cable, a MIDI DIN to 3.5 mm TRS type A adapter and a printed quick-start guide. The manual and firmware updates are listed as “coming soon” on the support page.
Who it is for
- Ambient, drone and experimental musicians looking for evolving, hands-on textures with no screen or menus.
- Live players: every knob does one thing, and USB-C power from a power bank means it can run away from a wall socket.
- Anyone processing other sources: the Feed input also makes it a resonator for a drum machine or a voice.
It is not an all-round first synth: with no conventional oscillators or adjustable envelopes, it will not do subtractive basses or classic pads. For those basics, see our guide to choosing a first synth: analog, digital or hybrid.
What it costs
$549 on Synthux Academy’s official store, shipping from December. For a limited time, Synthux covers import duties and taxes for the US and the UK; for the European Union, the page says VAT is included, without showing a euro price when we checked.
What it competes with
- Arturia MicroFreak: its digital oscillator includes a KarplusStrong mode among more than a dozen engines, plus a touch keyboard, sequencer and mod matrix, for considerably less money. It does plucked strings among many other things; Audrey III makes feedback its whole identity, with three voices, a resonance input and dedicated effects. See our Arturia MicroFreak spec sheet.
- SOMA Lyra-8: the benchmark eight-voice “organismic” drone synth built on feedback, with richer interaction between voices, but considerably more expensive.
Put simply, Audrey III targets a spot few instruments fill at this price: a compact, USB-powered, MIDI-controllable drone synth. No verdict on the sound here, as we have not heard it: the product page offers a playable in-browser demo of the engine.


