Product Review
 

Bryston BP-26DA Stereo Preamplifier with Built-in DAC

Part III

November, 2007

John E. Johnson, Jr.

 

On the Bench

For the bench tests, I used an XLR input and XLR output. Bandwidth for THD+N tests was 80 kHz. The input impedance of our Audio Precision was set to 100 kOhms.

Bryston states that they have lowered the distortion in the latest version of this product, and it shows. At 1 kHz and 2 volts output, THD+N was only 0.003%.

When the 1 kHz was input as a digital signal (16/44), THD+N went up a bit, but was still very low, at 0.005%.

At 10 kHz, still very low THD+N.

And using the DAC, although up a bit again, still very low.

IMD was also low, at 0.002%.

Inputting the signal via the DAC, IMD went up to 0.008%, but that is still very low. You can see the IMD peaks (red arrows) compared to no visible peaks in the graph above. So, using the DAC does add some distortion, but it is, in my opinion, such a low amount of distortion as to be an inaudible change.

Output through XLR clipped (1% THD+N) at 34 volts, using one channel. It is specified to be 30 volts output maximum with both channels operating, so this is right on the spec. Via unbalanced output, it will be 15 volts which is still plenty.

Below is what I consider to be one of the most important graphs for bench tests: THD+N vs. Frequency. You can see that distortion is just about a flat line across all frequencies for both 2 volts and 5 volts output. This means absolute neutrality in sound. If the graph goes up in the higher audible frequencies, it will add an "edge", and perhaps a little brightness, to the sound. Not necessarily bad (as long as the distortion is a low figure), since many consumers enjoy this, but it is not neutral. Kudos to Bryston here, as getting a flat response like this is difficult.

The measured frequency response was 20 Hz to 20 kHz, - 0.1 dB.

Conclusions

The Bryston BP-26DA is a superb preamplifier. The sound is neutral, with very, very low distortion. It is a reference quality product, and an ideal choice for anyone who wants to have ultra-high-end sound in their two-channel wireless media server setup (and even if you don't have a media server . . . yet).
 

- John E. Johnson, Jr. -

© Copyright 2007 Secrets of Home Theater & High Fidelity

Go to Table of Contents for this Issue.

Go to Home Page.

 

About Secrets

Register

Terms and Conditions of Use
 

PAGEFEEDBACK
Our Vault pages may have some display quirks. Let us know if we need to take a look at this page or fix a bug.
SUBMIT FEEDBACK
Connect with us
  • Instagram
  • Google+
  • YouTube
  • LinkedIn
  • Pinterest
Secrets "Cave"
Facebook
Close