This week we reviewed the Rega Aethos, a high-end model with a double mono design that uses audiophile-quality components to efficiently develop a high output power of 2 x 125 watts. Sold for €3999 and awarded multiple times by the specialist press, will this amplifier live up to the reputation of the British manufacturer?
Rega Aethos: the brand
Rega is a British brand founded in 1973 by Tony Relph and Roy Gandy. At the time, Roy was working as a technical editor for Ford and spent his evenings making his first turntable, the Rega Planet. More powerful and reliable than rival models, this Rega turntable quickly gained an excellent reputation and sales were such that Roy Gandy was able to quit his job at Ford to concentrate exclusively on Rega. He then opened a factory located in Rochford in the Southeast of England to meet the growing number of orders.
In 1975, the British manufacturer presented the iconic Rega Planar 2 turntable. This model rapidly gained a reputation as one of the best turntables in its price range. More than 45 years after its release, the latest generation of the Rega Planar 2 is still part of the manufacturer’s catalog and benefits from the brand’s latest innovations. One of Rega’s biggest strengths is that it constantly improves its different turntable ranges.
In 1977, Rega revealed its latest model, the Planar 3. The British magazine HI-FI News and Record Review didn’t hide its enthusiasm, writing, “The complete unit is worth a look”. With the success of this new model, the small Rochford company quickly grew. By 1980, the latter employed 13 people, had 20 distributors in the UK alone, exported its turntables to 12 different countries and even had to put customers on a waiting list. Rega then bought an old mill near Rochford and transformed it into a factory to meet the requirements of the market.
In the early 80s, the British manufacturer began designing tonearms, releasing the Rega RB300 in 1983 and the Rega RB250 in 1984. With over 400 000 units sold, the Rega RB300 tonearm became a reference for audiophiles and its successor can be found on the Rega P3 turntable. Five years later, production of the Rega Bias and Rega Elys cartridges began. After only a month, the company sold over a thousand units.
The 90s marked a major turning point for Rega. In addition to producing its iconic turntables, the manufacturer began designing and building hi-fi electronics with the Rega Elex and Rega Elicit amplifiers. Two entirely analog models designed to meet the highest performance standards. These characteristics can be found with all the brand’s amplifiers, including the subject of this review, the Rega Aethos.
Rega Aethos: packaging and accessories
The Rega Aethos amplifier comes in a cardboard box inside of which it is held in place and protected by thick sheets of polystyrene. It comes with a quick start guide and an infrared remote control. The latter provides access to all the main management functions for the amplifier, but also those of the brand’s CD players.
Rega Aethos: presentation
The Rega Aethos is the fifth amplifier made by the British manufacturer. It is the intermediary model between the Rega Elicit-R and the top-of-the-range Rega Osiris. Its design is a subtle blend of both models. It features a robust chassis made of thick metal panels. On either side of the amplifier, there are two large heatsinks on which the transistors are mounted. By placing these passive heatsinks on the outside of the device, the Rega Aethos amplifier benefits from a chassis without any perforations, which means that the internal components are protected more effectively from electromagnetic interference. Lastly, the chassis rests on wide metal feet, the base of which is covered with a rubber pad to absorb unwanted vibrations.
Underneath its robust chassis, the Rega Aethos amplifier features a double mono structure that uses a Class A polarized preamplification circuit. The latter is paired with an amplification section in which each channel benefits from a very low-impedance control stage using four Darlington-type Sanken transistors mounted in a double push-pull layout. These transistors are used for their theoretical dissipation of 16 amperes and 160 watts. This design enables the Rega Aethos amplifier to provide a similar performance and sound to a pure Class A amplifier, while producing less heat and consuming considerably less power. The Rega Aethos can therefore deliver up to 2 x 125 watts into 8 ohms or 2 x 125 watts into 6 ohms. The use of low-impedance transistors also ensures that the Rega amplifier delivers this output power across a wide bandwidth, from 10Hz to 30kHz and 10Hz to 50kHz in direct mode and with a very low distortion rate.
To handle the widest dynamic range, the Rega Aethos hi-fi amplifier is equipped with a regulated power supply that uses a large, low-noise toroidal transformer. Situated in the center of the amp, this transformer is paired with 1000μF Rega K-Power QC111 filter capacitors to ensure a high power reserve as well as a perfectly linear and clean power supply.
The British manufacturer has paid a great deal of attention to the Rega Aethos amplifier’s volume control system. It is controlled by an ALPS RK27 potentiometer from the Blue Velvet series that is combined with a feedback loop to ensure extremely precise adjustment of the gain stage. The latter uses JFet transistors to prevent loss. The level is adjusted by the preamplification circuit and not the potentiometer itself, which ensures that there is no unbalance between the two channels and optimizes the precision of the volume. This design also ensures reduced noise and saturation, as only the gain required to amplify the signal is applied. Such a volume control system is usually found on professional equipment where the adjustment must be extremely precise and without any noise whatsoever. The volume can be controlled by the large motorized potentiometer located on the front panel of the amplifier. However, during our review we found that the control was more precise using the infrared remote control.
The Rega Aethos amplifier has an exclusively analog design. Its connectors include 6 RCA inputs, which allow you to connect a CD player, phono preamp, network media player or an audio DAC, for example. The Rega amp also features a Direct In stereo input so that it can be used as a power amplifier, as well as a pre-out connector to pair it with an external power amplifier. Lastly, its speaker terminals can accommodate thick gauge cables, banana plugs and spade connectors. They are gold plated to ensure optimal contact and to maximize the signal transfer.
Rega Aethos: specifications
- Aluminum chassis
- Double mono design
- Toroidal transformer
- Rega K-Power filter capacitors
- Sanken transistors
- Class A amplification
- Passive volume control
- 2 x 125 watts RMS into 8 ohms
- 2 x 156 watts RMS into 6 ohms
- Frequency response: 10Hz (-0.8dB) to 30kHz (-0.5dB)
- Frequency response (direct mode): 10Hz (-0.8dB) to 50kHz (-0.5dB)
- Input sensitivity: 224mV at 17 Kohms
- Maximum output level: 11.5V
- Direct input sensitivity: 840mV at 50 Kohms
- Gain (Direct input): 31.6dB
- Total harmonic distortion + noise: 0.007%
- Output power into 32 ohms: 2.7V
- Output power into 54 ohms: 4V
- Output power into 300 ohms: 9V
- 6 x RCA line inputs
- 1 x Record output
- 1 x Record Link output
- 1 x Direct In input
- 1 x Pre-out output
- Dimensions (W x H x D): 433 x 95 x 360mm
- Weight: 17.5kg
Rega Aethos: listening conditions
For our review of the Rega Aethos amplifier, we connected it to Klipsch Heresy IV speakers, 3-way models equipped with a 12” woofer, using QED XT40i cables. Afterwards, we paired it with the Jean-Marie Reynaud Voce Grande compact speakers, models with an AMT tweeter capable of reaching 30kHz, using Jean-Marie Reynaud HP1132 cables. For our source, we used the Zappiti One SE 4K HDR network media player that we connected using Viard Audio Premium HD RCA cables. We used the latter to play 24-bit/192kHz flac files shared over the local network and Pure Audio Blu-rays. We also used a Hi-Res compatible network media player to stream music from Spotify and Qobuz. The latter was connected using Audioquest Yukon RCA cables.
Rega Aethos: listening impressions
We kicked off our review of the Rega Aethos amplifier by listening to Michael Jackson’s album Off The Wall. Right from the very first songs, the Rega Aethos proved to be particularly dynamic and had no trouble in bringing vitality to the tracks. The sound was perfectly balanced, with deep and full lows, rich and warm mids, and transparent highs. The soundstage was wide and filled our test room. The different acoustic levels were nicely structured and each tiny detail was perfectly audible.
The Rega Aethos’ dynamic character was confirmed with the album The Four Seasons by Anne-Sophie Mutter. The significant dynamic shifts present in these iconic pieces by Vivaldi were expertly handled by the Rega Aethos. It managed to reproduce the most powerful upswings without protest or the slightest hint of distortion, even at high volume.
In addition to its dynamic character, the Rega Aethos amplifier was also very delicate when the music called for it. On Stan Getz and Joao Gilberto’s track Corcovado, the sound produced by the Rega Aethos was gentle and warm. The fact that the Rega Aethos’ works like a Class A amplifier was evident here. It was almost as if we were listening to a tube amplifier. Astrud Gilberto’s voice was soft, natural and perfectly reproduced at the center of the soundstage. The different accompanying saxophone notes were full and clear. The overall restitution was bursting with cleverly structured details.
Rega Aethos: compared to…
Marantz PM-KI: retailed at the same price, the Marantz PM-KI has the advantage of incorporating a high-quality phono preamplifier compatible with MM and MC cartridges. Regarding sound, it is a little less dynamic than the Rega model, but provides a much warmer restitution. The different sound levels are excellently structured with both amplifiers, but the Rega is better at bringing out the smallest details in recordings.
Naim Uniti Star: sold for €4299, the Naim Uniti Star’s sound signature is pretty similar to that of the Rega Aethos. It provides plenty of energy and precision. However, its output power is limited to 2 x 70W into 8 ohms, compared to 2 x 125 watts for the Rega amplifier. Despite this, the Naim Uniti Star is more versatile thanks to its numerous streaming features. It is equipped with an aptX Bluetooth receiver, AirPlay and Chromecast, and it handles many online music services as well as playback of DSD and 24-bit/192kHz PCM files shared over the local network (DLNA). Consequently, it is a strong contender to which you won’t need to connect an external network player to enjoy digital music.
McIntosh MA252: €1000 more expensive than the Rega Aethos, this McIntosh amplifier is a hybrid model with vacuum tube preamplification. This design makes it sound even warmer and smoother than the Rega Aethos. It is particularly skilled at reproducing jazz and acoustic music. On the other hand, the Rega Aethos is more dynamic and versatile. It is also more generous at the low end of the sound spectrum, with deeper and better-defined lows. Lastly, the Rega Aethos features a broader range of connectors, with 6 RCA inputs, compared to only 2 unbalanced RCA inputs and one XLR balanced input for the McIntosh model.
Rega Aethos: conclusion
With the Rega Aethos, the British manufacturer offers a versatile amplifier that is difficult to fault. It is very dynamic, but also warm and soft when needed. The different levels are always perfectly structured and the soundstage is spacious and natural. Its significant power reserve ensures compatibility with any type of speakers, even those reputed to be somewhat demanding. That said, it’s a shame that it didn’t include tone correction and balance to allow users to adjust the sound based on personal preferences or the acoustics of the room.
The Rega Aethos amplifier’s high power reserve and flexibility ensures compatibility with many different speakers. Any compact model will benefit greatly from being paired with this amp, especially Jean-Marie Reynaud models, which are built according to principles dear to both brands. The Rega Aethos is also a good match for floorstanding speakers like the Davis Courbet N°5s, Elipson Legacy 3230s and Sonus Faber Sonetto IIIs.
What we liked:
- The dynamism
- The warm and lively sound
- The accurate timbres
- The power reserve
- The very attractive design
What we would have liked:
- Tonal balance and correction
- A Phono MM/MC input