Preamplifiers

Bryston BP17 Stereo Preamplifier

ARTICLE INDEX

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%.

Bryston BP17

 

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.

Bryston BP17

 

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.

Bryston BP17

 

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.

Bryston BP17

 

IMD at 2 volts output was 0.003%.

Bryston BP17

 

 . . . and at 5 volts output, IMD was unchanged.

Bryston BP17

 

THD+N vs. Frequency is shown below. Regardless of the output, distortion remained below 0.004% throughout the audible band.

Bryston BP17

 

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.

Bryston BP17

 

The measured frequency response was flat to 20 kHz, and the rolled off 1.5 dB at 100 kHz.

Bryston BP17