Moonriver 404 integrated amplifier


Moonriver Model 404 is the outcome of a 3-year research, the aim being to achieve incredible performance regardless of price range. The 404 amplifier will extract hidden elements and render textures from within any audio format, with the source, speakers and room to set the limits. Its culture will suit all music, as the Model 404 is by design set to define the faintest nuances of which tone integrity is composed.

A hefty supply section ensures that ample healthy power is available at all times at all stages through separate rails. A fully discrete preamp section serves for acute dynamic awareness, while a high output stage that is custom-optimized for bandwidth and distortion warrants for neutral predisposition and transient fidelity. A laborious selection of components armors the design against tonal alteration, pretentious or not, thus preserving naturalness throughout the shortest feasible path.


Furthermore, an integrated phono stage, a USB DAC, two preamp outputs and a tape monitor loop expand functionality to form an ideally flexible integrated amplifier.

Moonriver 404 amplifier is modular by nature; it can accommodate an MM or MM/MC phono stage and a USB asynchronous DAC.  Fitting these modules is simple and can take place at any time, on or after purchase.  The USB DAC may also be upgraded with a newer version to meet future needs.


Model 404 incorporates no less than 5 separate power supplies, each featuring overload protection. The power amplifier specifically runs on a dual mono configuration, beginning from separate windings on the toroidal transformer.

Signal switches are implemented via relays, while volume attenuation is trusted on the legendary blue ALPS pot.

A soft start circuit based on a 30A relay ensures that even the on/off switch is thought out to work with virtually no burden or wear for decades.


Components are carefully selected for both suitability and reliability. We make no use of surface-mount in analog circuits, despite the fact that through-hole costs more and requires advanced space management & layout strategies.

Each element utilized has to be of proven stability and sustained higher performance -proficient implementation provided- before making it into our analog paths.

As for the sound, we are not to say whether Model 404 is virtually transparent or inherently forgiving. Voicing it to appreciate the playlist and respect the user at all times has been the sum of all of our effort; a sincere effort to achieve effortlessness.

Specifications
  • phono stage and USB DAC respectively, 1 x tape loop)
  • Outputs: 2 x preamp out, 1 x rec out
  • Power output: 50 W per channel into 8 Ω
  • Frequency response: 10 Hz to 50 kHz
  • Total harmonic distortion: 0.05%
  • Signal to noise ratio: 95 dB (line)
  • Dimensions (mm): 430 (W) x 390 (D) x 135 (H)
  • Weight: 12 kg