Moonriver 404 Reference Integrated Amplifier, Reference Class

The Moonriver 404 Reference is the reference version of the 404 integrated amplifier, with massively more power-supply capacity for noticeably more dynamics and calm in the sound.

Almost identical to the standard 404 on the outside – black front, walnut side cheeks, the same four knobs – it packs a different calibre on the inside: instead of 57,000 µF total capacitance, the Reference version brings 107,000 µF, of which 21,000 µF is reserved exclusively for the preamp stage. If you want to hear the difference, you don't have to guess: it's there as soon as the music turns dynamic.

Why the Moonriver 404 Reference?

Because it takes the philosophy of the standard 404 – honest analogue technology instead of a fireworks display of features – and follows it through consistently. WBT nextgen speaker terminals for demanding loads, relay-based signal switching with the legendary ALPS potentiometer, a soft-start circuit via a 30 A relay against inrush current spikes: details rarely found this consistently in an integrated amplifier of this price class.

What you get

The same modular expandability as the standard 404 – phono module MM or MM/MC, SPDIF or USB DAC module, each separately retrofittable – paired with a preamp stage that, thanks to its own 21,000 µF reserve, works more independently of the power-amp load. The balance control, stereo/mono switch and tape loop remain on board unchanged.

Who is the 404 Reference suited for – and who isn't it for?

Straight talk: for anyone who already knows they want a Moonriver 404 and is willing to pay extra for noticeably more power-supply reserve – for example with demanding, low-impedance speakers. If you're already happy with how the standard 404 sounds on your speakers, you don't automatically need to upgrade: the difference shows up mainly with dynamically demanding music and critical loads, not equally clearly in every combination.

Our verdict

An integrated amplifier that combines the restraint of the standard 404 with tangible technical reserves. Jason Victor Serinus put it succinctly in his review for Stereophile (January 28, 2021): "Whatever I played through the Moonriver 404 Reference sounded right and gave me consistent pleasure." If your budget allows, the Reference is the more consistent choice.

Technical data – Moonriver 404 Reference

• Type: integrated amplifier with fully discrete preamp circuit, reference version
• Amplifier principle: dual-mono power-amp layout, 5 independent power supplies, each with its own overload protection
• Power-supply capacitance: 107,000 µF total, of which 21,000 µF exclusively for the preamp stage
• Output power: 2 × 50 W at 8 Ω
• Frequency range: 10 Hz – 50 kHz
• Distortion (THD): 0.05%
• Signal-to-noise ratio: 85 dB (line)
• Volume control: relay-based signal switching with ALPS potentiometer
• Inrush protection: soft-start circuit via 30 A relay
• Speaker terminals: WBT nextgen
• Inputs: 5 analogue inputs incl. tape loop, including slots for an optional phono and USB DAC module
• Outputs: 2× pre-out, 1× recording out
• Housing: steel chassis with solid walnut side cheeks
• Standby power draw: 22 watts
• Optionally retrofittable: phono module MM or MM/MC, SPDIF or USB DAC module (only one digital module at a time)
• Dimensions (W×H×D): 43 × 13.5 × 39 cm
• Weight: 13 kg
• Origin: handmade in Malmö, Sweden
• Warranty: 3 years (manufacturer)

Frequently asked questions

What's the difference between the 404 Reference and the standard 404?

Mainly the power-supply capacitance: 107,000 µF instead of 57,000 µF, of which 21,000 µF is exclusively for the preamp stage. On top of that come WBT nextgen terminals, relay-based volume control with an ALPS potentiometer, and a soft start via a 30 A relay. Power and the basic circuit are identical.

Is the surcharge over the standard 404 worth it?

That depends on your speakers and your demands. With dynamically demanding music and low-impedance loads, the Reference delivers noticeably more reserve. Bring us your speaker data and we'll tell you honestly whether the difference is worth it for you.

Can I retrofit the phono and DAC module at the same time?

The phono module, yes, plus one digital module (SPDIF or USB) as well – you just can't fit two digital modules at the same time, since there's only one slot provided for that.

How heavy is the 404 Reference compared to the standard 404?

13 kg versus 12 kg for the standard 404 – the extra power-supply capacitance noticeably tips the scales. Housing dimensions are identical.

Why buy the Moonriver 404 Reference from HD Zürisee?

Because we tell you honestly whether the Reference version is worth it for your speakers, instead of automatically recommending the more expensive model. Call us or message us on WhatsApp – we'll advise you in Wädenswil on the right combination.

Goes well with

Demanding floorstanding speakers, a turntable for the retrofittable phono module, and a clean speaker cable.