Moonriver Audio 404 Reference Integrated Amplifier
Refined 50 Watt Integrated Amplifier With Enhanced Power Supply And Modular Architecture
The Moonriver Audio 404 Reference is a high-performance integrated amplifier developed as an enhanced evolution of the original Model 404 platform. It retains the same core design philosophy, classic ergonomics and modular architecture while introducing significant improvements to the power supply and mechanical construction.
With its substantially increased power-supply capacitance, fully discrete preamplifier section and custom-optimised high-output stage, the 404 Reference is engineered to deliver greater dynamic authority, deeper low-level resolution and improved control across a wide range of loudspeakers.
The result is an amplifier designed to preserve natural tonal integrity while revealing the textures, spatial information and dynamic contrasts contained within the recording.
Key Features
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50 W per Channel into 8 Ω – A powerful and carefully engineered output stage designed to deliver controlled, dynamic performance across a wide range of loudspeakers.
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Enhanced 107,000 µF Power-Supply Capacitance – A substantially upgraded power supply designed to improve dynamic behaviour, low-level resolution and bass authority.
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Dedicated 21,000 µF Preamp Supply Reserve – Additional capacitance is reserved for the preamplifier section to support dynamic awareness and signal integrity.
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Fully Discrete Preamplifier Section – Designed to preserve natural tonal integrity and provide highly responsive dynamic performance.
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Custom-Optimised High-Output Stage – Engineered for wide bandwidth, low distortion and accurate transient reproduction.
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Modular Architecture – Supports optional MM or MM/MC phono stage and asynchronous USB DAC modules.
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WBT Nextgen Speaker Terminals – Designed to support reliable high-current transfer to the loudspeakers.
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Improved Mechanical Construction – A sturdy chassis with enhanced mechanical support and additional resonance control.
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Two Preamplifier Outputs and Tape Monitor Loop – Provides flexible integration into advanced two-channel systems.
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Enhanced Power Supply For Greater Dynamic Authority
The defining difference between the 404 Reference and the standard Model 404 lies in the power supply.
The 404 Reference increases total power-supply capacitance to approximately 107,000 µF, with approximately 21,000 µF reserved specifically for the preamplifier section. This substantial increase is designed to provide greater current reserve and improved stability during demanding musical passages.
The result is a design intended to deliver greater dynamic authority, improved retrieval of low-level information, a more articulate soundstage and stronger bass control.
Natural Musicality And Transient Fidelity
A fully discrete preamplifier section provides the foundation for the 404 Reference's dynamic and musical character. This works together with a custom-optimised high-output stage designed to balance bandwidth, distortion and transient fidelity.
The signal path is kept as short as practical, while carefully selected components are used to minimise unwanted tonal coloration. The design philosophy is straightforward: preserve the natural character of the recording while allowing the amplifier to reveal the texture and nuance contained within the music.
Modular Architecture For Long-Term Flexibility
The 404 Reference is designed as a modular platform that can evolve with the listener's system.
An optional MM or MM/MC phono stage can be installed to provide integrated vinyl playback capability, while an optional asynchronous USB DAC module adds high-resolution digital playback.
The modular design also allows the digital section to be upgraded as new technologies and future requirements develop.
Optional High-Resolution Usb Dac
The optional USB DAC module is based on ESS Sabre 9000-series conversion technology and supports native DSD playback.
The module supports PCM up to 384 kHz / 24-bit and DSD up to DSD128. Its USB input section uses an XMOS-based interface with custom firmware and dedicated low-drift clocking.
The digital and analogue sections use separate power-supply stages, with additional attention given to the analogue output stage to preserve the dynamic and natural character associated with the Moonriver design philosophy.
Classic Design With Modern Ergonomics
The 404 Reference combines classic styling with carefully considered modern usability.
Oversized aluminium controls, solid walnut side cheeks and a sturdy chassis give the amplifier a distinctive physical presence, while the user interface is designed for direct and intuitive operation.
Four knobs and three switches provide direct access to the amplifier's principal functions without complicated menus, hidden settings or multifunction controls.
Specifications
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Model: 404 Reference
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Type: Integrated Stereo Amplifier
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Output Power: 50 W per channel into 8 Ω
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Inputs: 5 total; Line 1 and Line 4 can optionally accommodate phono stage and USB DAC modules; 1 × tape monitor loop
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Outputs: 2 × preamplifier outputs; 1 × record output
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Frequency Response: 10 Hz – 50 kHz
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Total Harmonic Distortion: 0.05%
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Signal-to-Noise Ratio: 85 dB (line)
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Idle Power Consumption: 22 W
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Power-Supply Capacitance: 107,000 µF total; 21,000 µF reserved for the preamplifier section
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Dimensions: 430 W × 135 H × 390 D mm
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Weight: 13 kg
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Optional Modules: MM or MM/MC phono stage; asynchronous USB DAC
Why Buy From Soundtrails
An integrated amplifier is the central component of a two-channel system, and selecting the right model involves much more than comparing power ratings. Loudspeaker sensitivity, room size, speaker impedance, source components and listening preferences all influence the ideal amplifier choice.
At SoundTrails, our Audio Video Architects help you build carefully matched high-fidelity systems around your loudspeakers, room and listening preferences. From amplifier and speaker matching to vinyl playback, digital source integration and complete two-channel system design, we help ensure that every component works together as part of a balanced and carefully engineered system.
