Moonriver 404 Reference

Moonriver 404 Reference – Swedish craftsmanship with a vintage character

A significant step beyond the standard 404

The Moonriver 404 Reference builds on the already praised standard 404 by massively upgrading the power supply. Capacitance rises from 57,000 µF to 107,000 µF — of which 21,000 µF is reserved exclusively for the preamplifier stage. Consequently, the 404 Reference delivers greater dynamic range, deeper and more controlled bass, and a more articulate stereo image. Since only 50 W per channel is on offer, it therefore proves that power supply quality matters far more than output figures.

Discrete preamplifier and dual mono power supply

The preamplifier section is fully discrete — designed above all for acute dynamic awareness and minimal coloration. The output stage runs in a dual mono configuration, with separate transformer windings per channel. As a result, channel separation is maximised and the stereo image is stable and precise. Furthermore, five separate power supplies — each with overload protection — ensure a quiet noise floor and ample dynamic headroom under all conditions.

Modular architecture and intuitive controls

The 404 Reference accepts an optional phono stage — MM or MM/MC — and an optional DAC module with USB and SPDIF inputs based on the ESS Sabre 9000 chip. Since modules fit without soldering, they can be added at any time after purchase and upgraded to newer versions later. Moreover, a balance control, stereo/mono switch and tape monitor loop are included as standard — the latter allowing insertion of a room correction processor or any other line device. Four aluminium knobs and three switches give direct access to every function, with no display or hidden menus.

WBT Nextgen terminals and Swedish build quality

Speaker terminals are WBT Nextgen — a benchmark for contact quality and current transfer. Since Moonriver uses only through-hole components in all analogue circuits, long-term reliability is thereby built into every board. Each unit is hand-assembled in Malmö, Sweden and backed by a three-year warranty. Stereophile awarded the 404 Reference a Class A rating — the highest distinction in their annual Recommended Components guide.

Specifications

• Type: integrated amplifier, Class AB, dual mono power supply
• Output power: 50 W / 8 ohm
• Inputs: 4× line RCA + 1× tape loop
• Outputs: 2× preamp out RCA + 1× rec out
• Phono: optional MM or MM/MC
• DAC optional: USB ESS Sabre 9000 (PCM 384kHz/DSD128) + SPDIF coaxial
• Capacitance: 107,000 µF
• Power supplies: 5 separate
• Speaker terminals: WBT Nextgen
• Volume control: Alps RK27
• THD: 0.05%
• SNR: 85 dB
• Frequency response: 10 Hz–50 kHz
• Dimensions: 430×390×135 mm
• Weight: 13 kg
• Warranty: 3 years
• Origin: hand-built in Malmö, Sweden

Frequently asked questions about the Moonriver 404 Reference

What is the difference between the Moonriver 404 and the 404 Reference?

The 404 Reference has a substantially larger power supply — 107,000 µF capacitance versus 57,000 µF in the standard 404. Consequently, dynamic range is greater, bass is more authoritative and the stereo image is deeper and more precise. The speaker terminals are furthermore upgraded to WBT Nextgen.

Is the 404 Reference suitable for sensitive loudspeakers?

Yes — since the dual mono power supply and massive capacitance provide exceptional current delivery, the 404 Reference works well with sensitive loudspeakers. Moonriver moreover designs it to drive a wide range of speakers, including more demanding models.

Can I add a phono stage or DAC after purchase?

Yes — the modular design makes it straightforward to fit a phono or DAC module at any time. Since no soldering is required, modules can be installed and later upgraded to newer versions without technical assistance.