Rega’s integrated amplifiers, side by side. Here is the Aethos alongside the models beneath it and their specifications, showing what your money buys at each step.

The Aethos is where Rega stops adding things. There is no DAC and no phono stage: five line inputs, a tape loop, a preamplifier output, a power amplifier input and a headphone socket. That is deliberate. Rega’s reasoning on the phono stage is worth repeating, because it is honest rather than convenient: the dual-mono chassis leaves little room for one, and the turntables most Aethos owners will pair with it, the Planar 6, 8 and 10, are usually fitted with moving-coil cartridges that deserve a better stage than could be fitted inside. Rega already makes those in the Aria and Aura. So the Aethos spends its budget on amplification alone, and it shows.

Brief product overview

A dual-mono Class A/B integrated amplifier delivering 125 watts per channel into 8 ohms and 156 watts into 6 ohms, using four 160-watt, 16-amp Sanken Darlington output transistors per channel with a low-impedance Class A driver stage, arranged as a complementary emitter follower emulating Class A conditions. The preamplifier stage uses Class A discrete circuitry throughout, with a combined feedback and passive volume control originally developed for the Elex-R, here improved with discrete FET input operational amplifiers using Linear Systems LSK389 FETs and an RK27 Blue Velvet potentiometer, an arrangement that keeps channel tracking accurate at low volumes. Power comes from a custom-wound toroidal transformer with regulated supplies for the amplification and driver stages. Connectivity is five RCA line inputs, a tape loop with parallel outputs so you can record and drive a headphone amplifier at once, a preamplifier output and a power amplifier input, plus a 6.35mm headphone output. There is no phono stage and no DAC. It weighs 17.5kg, with cooling fins along both sides, and is made in Southend-on-Sea.

How it sounds

The Aethos is the point in Rega’s range where the drive and timing that characterise the smaller amplifiers arrive with genuine authority behind them. It sounds effortless in a way the Elicit does not quite manage, holding complex music together at volume and giving instruments room to breathe, with the dynamic range and rhythmic precision that won it What Hi-Fi’s best amplifier over €3,000 award. The Class A preamplifier stage is the heart of it, and the volume control arrangement means the amplifier stays tonally consistent whether you play quietly or loudly, which is not true of every design at this level. Left running for a while it warms noticeably through the side fins, which is a consequence of how it is biased rather than a fault.

What we’d partner it with

For speakers, the Aethos has power to spare for most designs. We suggest the Fyne Audio F501SP, the UK Special Production version of the F501, built around a 150mm IsoFlare point-source driver with the 25mm magnesium dome compression tweeter at the centre of the cone, plus a second 150mm bass driver, firing down into Fyne’s BassTrax Tractrix diffuser. It is 91dB sensitive with an 8-ohm nominal impedance and a 30 to 180 watt recommendation, so the Aethos drives it comfortably. The SP version adds crossover components from the F700 series, Van den Hul silver-plated wiring, an aluminium sandwich plinth and a bi-wire panel with a fifth terminal for grounding the driver chassis against RF interference. Good alternatives from brands we carry are floorstanders from Sonus faber, Dali, Monitor Audio and Wharfedale.

For vinyl, note the Aethos has no phono stage, so a turntable connects through an external one. We suggest the Rega Planar 8 through the Rega Aos MC, a dedicated moving-coil stage whose circuit is taken closely from Rega’s reference Aura: two all-analogue stages with no digital control circuitry, low-noise FETs configured so that no bias current disturbs the cartridge coil, and wide gain and loading adjustment for low-output cartridges. It is the natural match for a Planar 8 fitted with the Apheta 3. As a Rega deck, the Planar 8 earths through its phono lead, so there is no separate ground wire to attach.

For digital, the Aethos has no converter either, so the source supplies it. We suggest the HiFi Rose RS451, a network streamer and DAC using dual ESS ES9027PRO converters, one dedicated to the preamplifier output, with a toroidal linear supply, an 8.8-inch touchscreen and playback to DSD512 and 768kHz PCM. It connects to a line input through its unbalanced outputs; note the Aethos has RCA inputs only, so the RS451’s balanced outputs cannot be used here. Its HDMI eARC input also lets a television join the system.

On cabling, use a well-made speaker cable of appropriate gauge for the run; the F501SP can be bi-wired if you prefer. AudioQuest and Chord are the cable brands we stock.

Who shouldn’t buy it

If you want a phono stage or a DAC built into the amplifier, the Aethos has neither, and the Elicit Mk5 includes both with 105 watts for considerably less. If you have several sources you switch between often, note that the Aethos cycles through its inputs rather than selecting them directly, which is a small but real irritation. And if you want Rega’s ultimate expression of this thinking, the Osiris sits above it.

The Aethos runs warm through the fins along its sides, so leave clear space either side as well as above it. For vinyl, connect the Planar 8 to the phono stage and the phono stage to a line inpup. For streaming, connect the RS451 to a line input using its unbalanced outputs and set its output level so the Aethos controls volume comfortably. The RS451 has a volume-controlled preamplifier output, so it could in principle drive the Aethos’s power amplifier input directly, but that bypasses the Class A preamplifier stage that gives the amplifier much of its character, so we would not. The F501SP has a fifth binding post for grounding the driver chassis; connect it if your environment suffers RF interference.