- Written by John E. Johnson, Jr.
- Published on 29 May 2013
On the Bench
All distortion measurements were taken from the XLR outputs and were within an 80 kHz bandwidth. The load was 100 kOhms except where noted.
At 1 kHz and 2 volts output, distortion was 0.003%.
At 5 volts output, distortion was a bit lower, at 0.001%. This reflects the increase in the input signal peak vs. the increase in the distortion peaks.
Using 19 kHz and 20 kHz sine waves as the test signal, at 2 volts output, the B-A peak at 1 kHz was 110 dB below the fundamentals.
At 5 volts output, the B-A peak was 107 dB lower than the fundamentals. The presence of only 2 visible side-peaks (on either side of the fundamentals) is also notable.
IMD at 2 volts output was 0.003%.
. . . and at 5 volts output, IMD was unchanged.
THD+N vs. Frequency is shown below. Regardless of the output, distortion remained below 0.004% throughout the audible band.
THD+N vs. Output Voltage indicated a robust power supply, as even the 600 ohm torture test yielded usable output with low distortion. Maximum output appears to be about 15 volts RMS.
The measured frequency response was flat to 20 kHz, and the rolled off 1.5 dB at 100 kHz.