Power Amplifier Reviews

Driven continuously into an 8-ohm load:
0.1% distortion at 1,029 watts
1% distortion at 1,223 watts

Frequency response RCA input:
–0.14 dB at 10 Hz
–0.04 dB at 20 Hz
–0.16 dB at 20 kHz
–7.25 dB at 50 kHz

Frequency response XLR input:
–0.13 dB at 10 Hz
–0.03 dB at 20 Hz
–0.16 dB at 20 kHz
–7.33 dB at 50 kHz

This graph shows that the M1’s single amplifier channel, driving an 8-ohm load, reaches 0.1 percent distortion at 1,029 watts and 1 percent distortion at 1,223 watts. Unfortunately, the dedicated 20-ampere branch circuit and transformer that supplies power to our test bench was not up to the task of measuring the full continuous power capabilities of the M1 with a 4-ohm load, so we can’t state the true maximum power output accurately. (At the point where our variable transformer cried uncle while the M1 was driving a 4-ohm load, the amplifier reached 0.1 percent distortion at 1,558 watts and 1 percent distortion at 1,757 watts. Be aware that the M1 appears to be capable of producing even more output with a 4-ohm load if more mains power is available.) An input level of 100.9 millivolts was required to produce an output of 2.83 volts into an 8-ohm load, indicating an overall gain of +28.97 decibels using the RCA input. When using the XLR input set to 0 dB, a level of 104.1 mv was required to produce an output of 2.83 volts into an 8-ohm load, indicating an overall gain of +28.70 dB.

THD+N from the amplifier was less than 0.017 percent at 1 kilohertz when driving 2.83 volts into an 8-ohm load using the RCA input. When using the XLR input under the same conditions, THD+N was also less than 0.017 percent. The signal-to-noise ratio with an 8-ohm load from 10 hertz to 24 kHz with “A” weighting was –94.18 dBrA using the RCA input and –94.74 using the XLR input.—MJP