Moonriver 404 Reference: A Gold Star Integrated From Sweden

Posted on 2025/03/11 by David Neice in Amplification, Gold Star Awarded // 0 Comments

Moonriver 404 Reference Amplifier Review – A World Wonder!

An ‘In the House’ Review by David Neice

MSRP: Base price without any options is $6400 (Canadian). As tested the price is $7145 configured with the optional MM/MC phono stage. Up to $1100 needs to be added for DAC options.

Verdict: Very simply I am conservatively rating this component as the best solid state integrated amplifier I have ever auditioned. In that respect it is something of a world wonder.

This amplifier has four core characteristics. It’s ability to render true tones is breathtaking. It’s handling of dynamics is superb. The bass response is deep and accurate. And finally, it organizes the sound field in an almost incomparable fashion.

I have no hesitation at all in awarding it a ‘Wall of Sound Gold Star’. I suggest solid state enthusiasts run and not walk to their nearest Moonriver dealer to check it out.

Integrated Amplifiers

Moonriver is a Swedish company that has been making waves in audiophile circles in recent years for its 404 integrated amplifiers, which are handbuilt in Malmo, Sweden. The Moonriver 404 Reference is a modestly-powered Class A/B design rated at 50Wpc into 8 ohms and 70Wpc into 4 ohms. For purposes of this review it is somewhat helpful for readers to note that I adore integrated amplifiers.

Years ago I used to own many varieties of separates, believing that the separation of the pre-amp stage and the amplifier stage was the best approach to high end sound. It is true that this does maximize flexibility in component matching, but there is a down-side. One can spend endless time mixing and matching and never really ‘get it right’.

Eventually I thought it better that the amplifier’s designer be burdened with the task of getting it right. By viewing that task as central to any superior overall design, I came to the view that integrateds were the best solution, at least for me. So for about three or more decades now I have relied on integrated amplifiers (both tube and solid state) as my go to solution for amplification. Partly this is just an application of the axiom ‘simple is better’, but it works for me.

Description

Thus we come to the Moonriver 404 integrated amplifier which is available in two versions, the standard 404, and the 404 Reference under review here. There has been some consistent buzz in the audiophile press about these two amplifiers and several glowing reviews already exist, mostly in Europe (Footnote 1). My main purpose here is to introduce the amplifier to a Canadian audience as Tri-Cell Enterprises has taken on distribution duties in Canada and it is no longer necessary to rely on the US distributor.

Functionally and cosmetically the two amplifiers are almost identical. The main difference is that the 404 Reference model adds increased capacitance to the power supply stage. This is said to increase clarity and smoothness. Not having both models in-house for direct comparison, I cannot evaluate this claim, but I am sufficiently smitten by the 404 Reference that I will take the claim as factual.

The chassis of this amplifier is retro-themed, with beautiful wooden plates as end pieces. The frontal face plate is dark black and there are touches showing here and there of these amplifiers being ‘old school’ or out of another era. The face plate offers up four solid round knobs that cover source selection, volume (Alps motorized), as well as balance (will wonders never cease) and tape monitor (another retro touch). As well, there is a simple push button control for on and off as the designer has opted not to keep the amplifier in a state of stand-by. Finally, two toggle switches adorn the front panel, one for stereo versus mono switching and the other to implement panel light control (off/dimmed/normal).

Around the back there are the usual inputs for high level sources (four are available) as well as a dedicated input plus a ground post for the optional factory-installed MM/MC phono stage. There is also advance consideration for a dedicated DAC on board as another optional input (Footnote 2) . There is a full tape loop with both RCA ins and outs (Footnote 3) as well as a pre-amp output that can be used to facilitate a subwoofer. Finally there are WBT speaker outputs which are a well crafted multi-connector design. An IEC power socket completes the rear panel.

A small remote is included with the amplifier and it handles all the functions except for power.

The designer of the amplifier and Moonriver’s chief engineer and founder, George Polychronidis, worked for many years in audio component repair, and so the case on the 404 is designed so that the top and bottom lids are both removable to enable easy servicing or repair. This designer takes seriously the idea that the Moonriver amplifiers should last a life-time for their owners and so the selection of discrete through the hole components and the chassis design has been maximized to enable a very long life of service.

The Moonriver website notes: ‘We also care for sustainability as well as for reliability. Moonriver products are covered by a 3-year warranty and are designed to last for decades without any need of maintenance.’

This is a commendable attitude and reflects the views held by other companies such as Canada’s Bryston and the original UK-based Quad. Perhaps such sustainability attitudes undergird the appearance of certain ‘audio classics’.

Design Details

Special care has been taken in the design of the preamp stage in both models of the 404 to affect the dynamics of the amplifier. This may be something like the amplifier’s secret sauce. For Mr. Polychronidis, the main objectives of good design are timing and dynamics. The 404 preamp stage features discrete components throughout because no integrated circuits offer the quality the designer was seeking (Footnote 4). A good preamp stage sets the pace and pushes the power amp stage to deliver its full potential, and so the ability to convey wide dynamic contrasts is therefore crucial.

A key difference between the standard 404 and the Reference model involves major changes made in the power supply section (Footnote 5). The standard model has 57,000 µF capacitance, which is nearly doubled to 107,000 µF in the Reference model – and of that, 21,000 µF are reserved for the fully discrete preamplifier section.

The objectives of this increase in capacitance are said to expand on all the good things about the output of the standard model by improving dynamics, digging out more detail and low level information while giving the lower frequencies more heft and authority.

Listening

I initially hooked the amplifier up to my trusty DALI Oberon 5 floor standers with some Audio Sensibility speaker cables. CD duties were handled by a Cambridge Audio 640C, with a Neotech OCC cable connecting it to the amp, and vinyl was played on a Gold Note Valore SE turntable with a HANA EL cartridge on-board, also using an Audio Sensibility for the phono cable. Later in the review period I added the Spendor Classic 3/1 speakers to the set-up and found that match to be ideal.

The Moonriver 404 Reference acquitted itself from the first few notes. Initially I had somewhat casually slapped on a ‘Blind Boys of Alabama‘ CD on the assumption that I would need to run in the amp for a few hours to saturate the numerous capacitors. But right out of the gate the 404 Reference showed exceptional promise, with deep fast bass being the main notable characteristic. This tendency to sharpen the bass lines of many albums was a constant throughout the whole auditioning period.

So, ignoring any ‘essential’ break-in period other than the first hour to warm up the amp, I then settled in to test the amp with many, many selections only a few of which will be noted here.

First up is the Van Morrison CD ‘Down the Road‘ and particularly the track ‘No Work and No Play‘, where Morrison shines on the alto saxophone. This track is a bouncy number, and the tonal quality of Morrison’s instrument is the best I have ever heard it. Late in the track there is the appearance of a baritone saxophone that competes with the alto sax for the attention of the listener. Generally, with most amps the baritone solo is recessed, but with the Moonriver 404 Reference the baritone sax takes on an distinct role and the tonal quality is very strong, which attracts the listener’s ear.

It is the accuracy in the tonal colours of various instruments that strikes the listener right away. I found this persistent characteristic covered all the tracks auditioned and it marks the 404 Reference out as unique.

For instance, my friend Noam Bronstein lent me an exotic ‘STS Digital’ CD called ‘Extended Dynamic Experience No.1’, compiled in the Netherlands. Evidently the company uses the masters of existing recordings and then submits them to digital tweaking for extra dynamic range.

It contains two tracks that are quite exceptional. The first discussed here is by Stevie Ray Vaughan, and in this case the track is called ‘Roughest Place‘ (Footnote 6). I have numerous records and CDs by Stevie Ray but this track is astonishing for its dynamic range and for the quality of the tonal colours rendered by his guitar rig. On the Spendor Classic 3/1 speakers in particular the track shines through as probably the best vocal representation of Stevie that I have ever heard.

Similarly, the next track on the CD is by Hans Theessink, the Dutch blues singer, and the track is called ‘Missing You‘. I have followed Theessink for many years but I have never heard his voice with this much punch. The extended dynamic range opens up the sound stage and renders all the instrumental voices clear and strong, with precise locational information. The lasting illusion is that Theessink is in the living room and only playing for the listener. It doesn’t get much better than this.

Ever onward, I played Sting’s classic CD ‘Mercury Falling‘, and this only confirmed my growing appreciation for the Moonriver 404 Reference. The two tracks ‘ The Hounds of Winter‘ and ‘ You Still Touch Me‘ in particular struck me as exemplary. The first track is quite a complicated piece of music, with deep background flourishes such as literally the sounds of ‘braying hounds’. The Moonriver 404 Reference was able to untangle these strange sounds and present a coherent and pleasing sound stage.

The second track offers the sharp cracks of a snare drum rim-shot throughout and again the ability of this amplifier to reproduce the wide dynamic range of these cracks makes the track sound quite real. The tonal colour of Sting’s singing voice is also unmatched by other amplifiers I have had in my system over the years. In this regard, readers should note my comment on ‘verisimilitude’ found below.

Turning to vinyl, I decided to celebrate the moment we are all experiencing with renewed interest in the early works of Bob Dylan. This reprise is being widely celebrated in the movie ‘A Complete Unknown‘. I decided to pull out copies of early and middle period Dylan records and use these as sources. So I rounded up copies of ‘Highway 61 Revisited‘ as well as ‘The Freewheelin’ Bob Dylan‘ and then ‘John Wesley Harding‘ and ‘Nashville Skyline‘, two albums that represent his middle period.

The Moonriver 404 under review is optioned with the switchable MM/MC phono stage onboard, and I had to change the factory settings, which were set for the MM option. Changing this required removing the amplifier’s lid as well as another cover over the phono board and then selecting some DIP switches to change. (Footnote 7)

The vinyl albums were played all the way through. Rather than isolate specific tracks, I think it is better to just summarize the total effects.

The Moonriver phono stage is both delicate and robust, a seeming contradiction, but let me explain. On simpler tracks such as found on ‘John Wesley Harding‘ and ‘Nashville Skyline‘ one notes the delicacy of the phono stage. It seems to soft glove the tracks and this adds to their inherent mystery. But on real rockers such as found on ‘Highway 61 Revisited‘ the ability of the amplifier to highlight dynamics leads one to believe that the phono stage is indeed quite dynamic.

‘Highway 61 Revisited‘ certainly ranks among the top rock albums of all time. It is always a pleasure to hear Bob Dylan at the height of his youthful powers. The Moonriver 404 Reference amplifier does complete justice to this magnificent collection of songs.

Similarly, the power of the songs on ‘The Freewheelin Bob Dylan‘ are rendered in all their original glory by the Moonriver.

I can vividly remember first hearing this album around 1964 on a Crossley type record player. Even with this primitive equipment the reach of Dylan’s lyrics and the power of the songs spoke immediately to the bracing times of the chaotic 1960s. Dylan was just beginning to sort out his ‘originals’, but his promise was there in spades. ‘Masters of War‘ and ‘A Hard Rain is Gonna Fall‘ are particularly striking as they are a testament to the escalation of the war in Vietnam and the continuing cold war with the Soviet Union, the premier political events of that era.

Again with ‘Freewheelin‘ the Moonriver 404 Reference lends delicacy and insight to these historic tracks. For many observers the current resurrection of Dylan’s early work is a revelation, as they have not been aware of the power of his poetic folk singing which is, after all, why he was awarded a Nobel Prize.

Notes In Passing

‘Verisimilitude’ is defined as ‘the appearance of being true or real’. There is no doubt in my mind that all of high-end audio rests on an illusion we call the stereo effect, and that this stereo effect in turn crucially depends on the extent to which ‘verisimilitude’ is achieved.

There are many factors that influence the degree of verisimilitude attained by a component, such as tonal colour, dynamics, imaging and soundstaging, as well as timing and pace. For instance we assess the accuracy and heft of a rim-shot on a snare drum by how close it sounds to our experience of reality. The reproduction of this event through a stereo system is a re-creation with various levels of believability attached. It is no exaggeration to say that the Moonriver 404 Reference amplifier offers the owner a level of verisimilitude that is rarely achieved.

Conclusion

The sort of performance that the Moonriver 404 Reference amplifier exhibits has been achieved once or twice before and is not limited to the performance of amplifiers. It is, however, worthy of special commendation and so I am awarding it a ‘Wall of Sound Gold Star’ for both performance and value.

As to the future, Moonriver Audio is already being mentioned as being in the company of other more widely known brands. Buyers should have no fear of them remaining a secret.

In closing I must congratulate the Moonriver team on their fine achievement. Well done!

Footnote 1: Stereophile has already given it a Class A rating.

Footnote 2: Moonriver was victim to the devastating three-day fire that broke out in the AKM factory in Japan halting production of their chips. For a period Moonriver found itself unable to offer the digital options it was planning.

Footnote 3: This tape loop enables the use of a digital or analogue room correction processor, a buffer, a graphic equalizer, a noise reduction system or indeed any other line device available to improve the sound of a connected source.

Footnote 4: Tarun, A British Audiophile, noted in his review of the 404 that while the pre-amp stage is all discrete components, the power stage uses op-amp circuits. Buyers may want to consider this aspect. The amp is indeed Class AB.

Footnote 5: A single toroidal mains transformer is used with five separate power supplies for enhanced dynamic contrast. The amplifier stage is A/B but is also dual mono in design.

Footnote 6: For Stevie Ray fans, this track is actually called ‘Tin Pan Alley (Roughest Place)‘ found on the album ‘Couldn’t Stand the Weather‘.

Footnote 7: My strong recommendation is that users rely on their dealer or distributor to make these changes. The operation is a bit tricky and the manual is not that clear.

The author and the publisher wish to thank Vince and David of Tri-Cell Enterprises (905-265-7870) for the loan of the review sample.