The Moonriver Model 404 Reference hi-fi amplifier is unique with its retro design inspired by the vintage amps of the late 70s. Its 2 x 50 watt class AB amplification promises to compete with much more powerful models thanks to its huge power capacity. The entirely analog connectors include many RCA inputs to connect all your sources. Two optional modules can complete the package with a USB-B input and a phono input. Marketed at €4,490 and praised by the specialized press, this amplifier promises to be among the best integrated systems on the market.
Moonriver Model 404 Reference: packaging & accessories
The Moonriver Model 404 Reference stereo amplifier comes with a power cable, a quick start guide and an infrared remote control. The latter features all of the essential controls to turn the amp on, select the source and adjust the volume remotely.
Moonriver Model 404 Reference: presentation
Design
Successor of the Moonriver Model 404 that has remained very confidential up until now, the Moonriver Model 404 Reference offers an even more sophisticated solution. Entirely handmade in the brand’s Swedish workshops, this amplifier adopts a retro design inspired by the models of the 1970s, with large knobs and a wood finish. Sleek and elegant, the all-metal chassis is extremely robust. Its considerable thickness forms an effective barrier against electromagnetic waves to ensure optimal operating conditions for the internal components. Like in the high-end automotive industry, the matte black coating reinforces the premium look of this device. It also has the advantage of resisting fingerprints. The vertical edges of the Moonriver Model 404 Reference amp’s front panel are covered with a real wood veneer that emphasizes its vintage and timeless aesthetic.
The front panel of the Moonriver Model 404 Reference amplifier features four knobs. The first three allow you to adjust the source, control the volume and adjust the left/right stereo balance. The volume control benefits from an ALPS potentiometer, a real reference in the audiophile sphere for its ability to ensure a smooth mechanical travel without altering the musical signal.
The Moonriver Model 404 Reference amplifier’s fourth knob is a tape monitor selector, a common feature on amps from the 80s. It allows you to quickly switch between the source currently playing and the source connected to the Tape input. This function was originally used to compare the quality of the tape or CD recording to that of the original source. It also allowed you to insert a correction processor, a noise cancelling system or any other equipment used to process tape recordings. Today, it is less useful, but it can be used as a buffer stage or to compare the quality of two analog sources more easily.
The Moonriver Model 404 Reference amplifier also features a switch to dim or turn off the display lights, as well as a mono/stereo switch to accommodate 78 RPM records, for example. Lastly, the power switch uses a soft start circuit based on a 30A relay that ensures a progressive flow of current to the various components to limit wear and ensure long term use. This soft start also allows the speakers to be switched on only when the components are loaded, thus preventing the amp from sending an electrical signal to the drivers (which often makes a popping sound) when the unit is switched on or off.
The Moonriver Model 404 Reference amplifier can also be controlled using the infrared remote control. Very well designed, the latter is made entirely of aluminum, which once again underlines the premium nature of this amp. Thanks to its ergonomic shape, the remote control provides a good grip and easy access to the various controls: source selection, control of the tape monitor function and volume control. The adjustment of the latter is extremely smooth and precise. Perhaps too much so. It is so gradual that you have to be patient if you want to significantly adjust the volume.
Toroidal transformer
Beneath its vintage exterior, the Moonriver Model 404 Reference hi-fi amplifier is packed with state-of-the-art technology. The dual mono power stage is absolutely spectacular, with a toroidal transformer featuring separate windings combined with five separate power supplies as well as high-capacity capacitors. This configuration provides a power reserve of over 107,000 microfarads, of which 21,000 are reserved for the preamplifier. This is almost double the 57,000uF of the original Moonriver Model 404 amp. This enormous capacitance is far superior to that of most multi-channel home theater amplifiers. This shows just how serious its design is. Thanks to this power reserve, the Moonriver Model 404 Reference amplifier ensures an exceptional dynamic performance and great depth in the lows.
While the announced output power of 2 x 50 watts into 8 ohms and 2 x 70 watts into 4 ohms may seem modest, the Moonriver Model 404 Reference amp compensates with a very high power reserve to ensure that the drivers are perfectly controlled. Its AB polarization provides a natural and warm reproduction across a wide bandwidth ranging from 10Hz to 50kHz, with a very low total harmonic distortion of less than 0.05%.
Connectors
The Moonriver Model 404 Reference amplifier’s old-school character is also reflected in its connectors, which are entirely analog. They include 5 RCA inputs, one of which is a Tape input. It is also possible to connect a CD player, a network player or, ideally, an external DAC to listen to Hi-Res music, which can be enjoyed thanks to the amp’s wide bandwidth. In addition to its many inputs, the Moonriver Model 404 Reference amplifier also has two pre-outs to connect a separate power amplifier or a subwoofer. In order to meet all needs, the Moonriver Model 404 Reference amplifier can be used with an optional phono module to connect a turntable, and with a USB DAC module. However, we would have preferred these two accessories to have been integrated as standard.
Moonriver Model 404 Reference: key specifications
- Output power of 2 x 50W / 8 ohms
- Very high power reserve of 107,000 microfarads
- 4 x RCA inputs + Tape input/output
- 2 x preamplified outputs
- Frequency response: 10Hz to 50kHz
- Dimensions (WxHxD): 430 x 135 x 390mm
- Weight: 13kg
Moonriver Model 404 Reference: listening conditions
We tested the Moonriver Model 404 Reference amplifier with the Dali Rubicon 6 and Elipson Legacy 3220 speakers, which were connected using Viard Audio Premium HD HP speaker cables. For the sources, we chose the Bluesound Node network player and the Marantz SACD 30N player.
Moonriver Model 404 Reference: listening impressions
The Moonriver Model 404 Reference amplifier demonstrated that a modest output power can tame demanding speakers when properly controlled. The musical reproduction was dense, energetic and displayed a lot of substance in the bass. The Moonriver Audio 404 Reference packed a punch and had more authority than more powerful models. The instruments were embodied with naturalness and conviction in the soundstage.
With jazz (various Stan Getz albums) and world music (Dead Can Dance and Enigma), the sound provided by the Moonriver Audio 404 Reference amplifier was marked by tranquility. The sound was very soft, rich and full. The mids were opulent and smooth. The Moonriver Audio 404 Reference had a tube-like sound that was very soothing thanks to precise and soft highs, silky mids and perfectly rendered vocals. However, its transistor design and very high power reserve allowed it to exhibit strong dynamics when the music demanded it. The latter were significantly superior to those provided by tube amplifiers, with a lot of energy to spare. The attacks were direct and demonstrated the exceptional impulse response allowed by such a huge power reserve. The Moonriver Audio 404 Reference amplifier always managed to correctly balance softness and vitality, depending on the music.
The Moonriver Model 404 Reference amplifier’s musical performance was incredibly refined. It reproduced each note with great finesse and real attention to detail. The slightest nuances could be clearly heard. The Moonriver Model 404 Reference made us want to listen to our reference tracks louder and for longer to discover hidden details.
The soundstage delivered by the Moonriver Model 404 Reference amplifier was pleasantly spacious, ensuring perfectly layered frequencies. The lows were firm, tight and brought a lot of substance to the sound. The Moonriver Model 404 Reference packed a punch in this frequency range, while remaining accurate, controlled and natural. The mids were exceptionally delicate. This benefitted the vocals, which are expressed with the utmost respect for the artists, and whose texture was reproduced with naturalness and softness in the center of the stage. The highs also took advantage of this soft reproduction. They were clear, pure and delivered with finesse. The superposition of these various frequencies conferred great depth to the sound.
Moonriver Model 404 Reference: compared to…
Cayin CS-150A: sold at the same price, the Cayin CS-150A is a vacuum-tube model and offers an even softer, warmer and fuller sound. The mids are slightly richer and the highs are even smoother. The lows are tight, but shallower and less impactful than those delivered by the Moonriver Model 404 Reference. Despite its more modest output power, the latter is more energetic, dynamic and generous in the lows.
Rega Aethos: also available for €4,490, the Rega Aethos is capable of delivering up to 2 x 125 watts into 8 ohms, from 10Hz to 30kHz. It stands out with its warm sound, thanks to a design that is similar to that of a Class A amplifier. The soundstage offered by this Rega amplifier is even more spacious and transparent. At sustained levels, however, the Moonriver Model 404 Reference has smoother highs. Finally, the connectors of the Rega Aethos amplifier are also strictly analog, with 7 RCA inputs, including one direct input. However, the Moonriver Model 404 Reference is more versatile thanks to its optional phono and DAC modules.
Moonriver Model 404 Reference: who is it for?
The Moonriver Model 404 Reference is a perfect solution to enjoy a luxurious hi-fi amplifier with a retro design. It is an excellent alternative to tube amplifiers, keeping their warm character while bringing more energy thanks to its transistor design and high current capacity. The output power of 2 x 50 watts may seem modest and discourage some users, but the very high power reserve bypasses this restriction and allows the Moonriver Model 404 Reference to power the most demanding speakers without difficulty. From small compacts to the largest floorstanders, the Moonriver Model 404 Reference will make the vast majority of speakers sing.
Moonriver Model 404 Reference: conclusion
With the Moonriver Model 404 Reference, the Swedish manufacturer has renewed its flagship amplifier to offer an even more refined, dynamic and balanced sound. The reproduction is still just as pure, warm and tonally accurate. The Moonriver Model 404 Reference impresses with its ability to combine a warm sound worthy of a tube amplifier with dynamics that can only be achieved with transistors. The 50W per channel easily competes with much more powerful models thanks to a power reserve seldom seen in hi-fi. This ensures an optimal impulse response, deep bass and a perfect power supply for many bookshelf and floorstanding speakers. Lastly, the design inspired by the most elegant models of the 70s and 80s makes this amplifier a real success in every respect, and one of the best references in its price range.
We liked:
- The very impressive retro design
- The incredible power reserve
- The warm and soft sound
- The high impulse response
We would have liked:
- For digital and phono inputs to have been integrated as standard
- Quicker volume adjustment with the remote control
