Moonriver 404 Integrated Amplifier, Handmade in Sweden

The Moonriver 404 is an integrated amplifier from Sweden built around pure analogue technology, with optional retrofittable phono and DAC modules.

"Fågelsång" – birdsong – is what Moonriver Audio calls its sonic ideal, and that's the whole programme: no loud showing off, but an amplifier that steps back and lets the music do the work. It's built by hand in Malmö, with five completely separate power supplies and through-hole rather than surface-mounted components in the analogue section – effort you rarely find at this price.

Why the Moonriver 404?

Because it shows that understatement works in amplifier design too: a plain black front with walnut side cheeks, four large aluminium knobs, three switches – done. Behind that sits a fully discrete preamp circuit in dual-mono layout, each channel half with its own power supply and its own overload protection. The balance control and the stereo/mono switch are details that turntable fans know to appreciate – not every integrated amp in this price class still offers that.

What you get

Five inputs, including slots for an optional phono module (MM or MM/MC) and an optional SPDIF or USB DAC module – so you only retrofit what you actually need, instead of paying for a factory fit-out that gathers dust on the shelf. Plus a tape loop for anyone still recording to analogue, two pre-outs for a later expansion with an active subwoofer or an external power amp, and a recording output.

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

Straight talk: the 404 is for anyone who wants an honest, unfussy amplifier without streaming ballast, and who values the freedom to retrofit phono or a DAC only when needed. If you expect network streaming built into the device from day one, the 404 isn't for you – that needs a separate streamer or a different model. And if your demands on the preamp stage are already at the top end, take a look at the 404 Reference straight away: more power-supply capacity, same housing, noticeably more reserves.

Our verdict

An integrated amplifier that doesn't show off with features but wins you over with clean execution – exactly the understatement that built its reputation in the specialist press. "Here was an amplifier that suited these values perfectly, by opening a compelling window onto your music" – Chris Thomas, hi-fi+, June 2021. If you value modular expansion over factory fit-out, it's one of the most honest choices in its price class.

Technical data – Moonriver 404

• Type: integrated amplifier with fully discrete preamp circuit
• Amplifier principle: dual-mono power-amp layout, 5 independent power supplies, each with its own overload protection
• 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)
• Inputs: 5 analogue inputs incl. tape loop, including slots for an optional phono and USB DAC module
• Outputs: 2× pre-out, 1× recording out
• Controls: 4 aluminium knobs, 3 switches, balance control, stereo/mono switch
• 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: 12 kg
• Origin: handmade in Malmö, Sweden
• Warranty: 3 years (manufacturer)

Frequently asked questions

Can I add a phono input to the Moonriver 404 later?

Yes. The 404 has free slots from the factory for a phono module (MM or MM/MC) and a digital module. Both can be retrofitted at any time without having to buy a new unit – our technician will fit it for you.

How does the 404 differ from the 404 Reference?

Both share the same housing, power and circuit concept. The Reference version brings significantly more power-supply capacity, which mainly benefits dynamics and detail resolution. If you want maximum reserves, go for the Reference.

Can I retrofit USB and SPDIF DAC at the same time?

No, there's only one slot for a digital module. You choose USB (computer/streamer via USB) or SPDIF (classic digital source) – both can't be fitted at the same time.

Does the 404 need a subwoofer connection?

It doesn't have a dedicated subwoofer output, but it does have two pre-outs. An active subwoofer with a line input can still be integrated cleanly through those – just ask us, we'll show you how.

Why buy the Moonriver 404 from HD Zürisee?

Because we show you which module actually suits your system before you pay for it – and take care of the fitting ourselves if needed. Call us or message us on WhatsApp, and we'll advise you in Wädenswil on speakers, cables and the right upgrade.

Goes well with

A turntable for the retrofittable phono input, plus matching bookshelf speakers or floorstanding speakers and a clean speaker cable.