Elysia xmax

In a world of retro homages, it’s always refreshing when a manufacturer looks to do something a little different...

As I noted when reviewing their xpector headphone amp and monitor controller in SOS January 2025, German company Elysia aim to develop audio equipment that’s not only of high quality but also has a “certain something”. Well, their latest release, the Class‑A xmax master bus processor, appears to deliver several such certain somethings!

Overview

The xmax is available in three different physical formats that have identical features, liveries, functionality and performance: there’s a 500‑series module, a similar‑looking but standalone Qube version, and a 1U 19‑inch rackmount variant. Being true stereo units, there’s only one set of front‑panel control knobs, and in the case of the rackmount unit that was loaned to me for this review, these are arranged in four groups (Threshold, Control, Gain and Shape), with two placed either side of a central section comprising a backlit logo, three latching button switches and a group of six small LED meters. Each control group comprises three knobs.

This unit’s rear panel carries all the I/O connectors, of course. These comprise a balanced input and output for each channel, presented on both XLR and TRS wired in parallel, and a second balanced TRS output (labelled Ext 2) for each channel. There’s an IEC mains connector, with an on/off switch, a fuse compartment, and 115/230 V voltage selector.

On the rear panel, you’ll find the usual analogue I/O on XLRs and jacks, and a globally compatible IEC power inlet with on/off switch.

While the xmax is designed to receive a left‑right stereo signal at the input, this is immediately encoded into Mid‑Sides (M‑S). The Mid is then split by a variable crossover filter (40‑470 Hz), to create two bands, described as Low and Mid (making it the Mid band of the Mid signal... I wonder if a different name for the band might have been helpful!). The Mid signal’s two bands and the Sides signal each then pass through one of three VCA compressors, each with its own threshold and make‑up gain controls — the threshold controls are the first trio on the left of the rackmount xmax, while the make‑up gains (±12dB) form the first trio to the right of the meters.

After any compression and make‑up gain you apply, the Mid and Low bands are recombined, and the Mid and Sides signals pass through the stereo ±8dB shelving high‑frequency equaliser (whose control is labelled Tone) before everything is decoded for delivery as L‑R stereo to a soft‑clipper stage that can be used to control high‑level transients, and, finally, the output level control.

I’ve discussed the compressor threshold controls already. The adjacent trio of knobs is labelled Control, and the first of them sets the Mid bands’ crossover frequency. The next specifies the release time (10ms to 1.7s), which applies to all three compressors. The third is used to link/unlink the three compressors’ control voltages, and ranges from them acting completely independently to being fully linked. When linked, the loudest control voltage takes precedence — the xmax behaves more like a conventional single‑band VCA compressor, but you can set the band thresholds to determine which parts of the signal are most likely to trigger gain reduction.

Next comes the three buttons, and when active each of these is surrounded by an illuminated LED ring. The first, labelled Hit It!,...