Moonriver Audio 404 Integrated Amplifier

Moonriver Audio 404 Integrated Amplifier

High-Performance 50 Watt Integrated Amplifier With Modular Phono And Dac Options

The Moonriver Audio 404 is a high-performance integrated amplifier designed for listeners who value natural musicality, dynamic expression and long-term system flexibility. Developed through an extensive research and development process, the 404 combines a fully discrete preamplifier section with a high-output power amplifier stage engineered for bandwidth, low distortion and transient fidelity.

With its carefully designed power supply, short signal path and thoughtfully selected components, the Model 404 is built to preserve the natural character of music while revealing subtle textures, low-level information and dynamic contrasts across a wide range of sources and recordings.

The 404 also offers an unusually flexible platform for a high-end integrated amplifier. Depending on configuration, it can accommodate an MM or MM/MC phono stage and an optional asynchronous USB DAC, while providing preamplifier outputs and a tape monitor loop for broader system integration.

Key Features

• 50 W per Channel into 8 Ω – A robust power amplifier section designed to deliver controlled, dynamic performance across a wide range of loudspeakers.

• Fully Discrete Preamplifier Section – Designed for high dynamic awareness and a natural, transparent signal path.

• Custom-Optimised High-Output Stage – Engineered for wide bandwidth, low distortion and accurate transient reproduction.

• Modular Architecture – Supports optional MM or MM/MC phono stage and asynchronous USB DAC modules.

• Integrated Phono Stage Option – Allows the 404 to become the heart of a high-performance vinyl playback system.

• Optional USB DAC Module – Provides high-resolution digital playback with support for PCM and native DSD, depending on the installed module.

• Two Preamplifier Outputs – Provides additional flexibility for active systems, subwoofers or external power amplification.

• Tape Monitor Loop – Retains useful connectivity for traditional analogue recording and monitoring systems.

• Classic Ergonomic Design – Direct-access controls, solid aluminium knobs, walnut side cheeks and a sturdy chassis combine classic styling with modern usability.

Natural Musicality And Transient Fidelity

The Model 404 is designed around a straightforward principle: preserve the natural character of the music while avoiding unnecessary tonal alteration.

A fully discrete preamplifier section works with a custom-optimised high-output stage to provide dynamic awareness, neutral tonal balance and accurate transient response. The carefully selected components and short signal path are intended to maintain the integrity of the source signal from input to loudspeaker.

The result is an amplifier designed to reveal the texture, timing and dynamic contrast contained within a wide variety of music.

A Power Supply Designed For Musical Dynamics

The 404 incorporates a substantial power supply designed to ensure that healthy power remains available across the amplifier's different stages.

Separate power rails help support the preamplifier and power amplifier sections, while the overall power supply architecture is designed to provide stable performance during demanding musical passages.

This approach contributes to the 404's ability to combine a natural presentation with controlled dynamics and confident transient performance.

Modular Architecture For Long-Term Flexibility

One of the defining features of the Moonriver 404 is its modular design.

The amplifier can accommodate an optional MM or MM/MC phono stage as well as an optional asynchronous USB DAC. These modules can be fitted at the time of purchase or added later, allowing the system to evolve as the listener's requirements change.

The modular approach also provides a degree of future flexibility, with the possibility of upgrading the digital section as newer DAC technology becomes available.

Designed For Vinyl And Digital Sources

With the optional phono stage installed, the 404 can form the central component of a high-performance analogue system. Depending on the installed module, the amplifier can support MM or MM/MC cartridge applications.

The optional USB DAC module adds high-resolution digital playback capability. Based on ESS Sabre DAC technology, the USB module supports high-resolution PCM and native DSD playback, with the exact supported formats depending on the installed module.

Together, these options allow the 404 to serve as a flexible centrepiece for both analogue and digital listening systems.

Classic Design With Modern Ergonomics

Moonriver Audio designed the 404 with a clear focus on usability and longevity.

The amplifier combines a classic visual character with modern construction, including solid aluminium controls, walnut side cheeks and a sturdy chassis. Instead of relying on complicated menus or multifunction controls, the 404 uses direct-access controls that allow the user to operate the main functions quickly and intuitively.

Its clean, tactile interface reflects the amplifier's overall design philosophy: straightforward operation, carefully engineered performance and long-term usability.

Specifications

• Model: 404

• Type: Integrated Stereo Amplifier

• Output Power: 50 W per channel into 8 Ω

• Inputs: 5 total; Line 1 and Line 4 can optionally accommodate phono stage and USB DAC modules; 1 × tape monitor loop

• Outputs: 2 × preamplifier outputs; 1 × record output

• Frequency Response: 10 Hz – 50 kHz

• Total Harmonic Distortion: 0.05%

• Signal-to-Noise Ratio: 85 dB (line)

• Idle Power Consumption: 22 W

• Dimensions: 430 W × 135 H × 390 D mm

• Weight: 12 kg

• 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 choosing the right model involves more than simply comparing power ratings. Loudspeaker sensitivity, room size, source components, listening preferences and future system expansion all influence the ideal amplifier choice.

At SoundTrails, our Audio Video Architects help you build carefully matched high-fidelity systems around your room, loudspeakers 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.