Readers interested in a full technical appraisal of the performance of the Moonriver 404 Reference Stereo Integrated Amplifier should continue on and read the LABORATORY TEST REPORT published on the following pages. Readers should note that the results mentioned in the report, tabulated in performance charts and/or displayed using graphs and/or photographs should be construed as applying only to the specific sample tested.
Newport Test Labs first measured the power output of the Moonriver 404 Reference using its usual test procedure, at frequencies of 20Hz, 1kHz and 20kHz, so as to ensure the amplifier could deliver its rated output anywhere across the audio band, as required by the Australian Standard for power output of high-fidelity amplifiers. As you can see from the tabulated results, as well as from the bar graph, the Moonriver 404 did not meet its rated output of 50-watts into 8Ω at any test frequency, even when only a single channel was driven.
In fact, recorded the Moonriver 404 Reference’s maximum power output as being 46-watts (16.6dBw) when a single channel was used a different measurement technique that allowed a little more distortion in the waveform, or ramped up the mains voltage a little, a specification-meeting power output might have been achieved. Also, of course, this is a test of continuous power. The short term or ‘dynamic’ power available, as required by music signals, would be higher.
