The Inner Ear Report
A magazine worth listening to.
Bryston BP-25 DA Preamplifier/DAC
This is the latest version of a model that has
been on the market for about six years. Bryston has improved the
performance of this preamplifier by adding an external power supply,
changing some of it¹s components and improving the unit¹s
layout. The current BP-25 can be considered a brand new component
from an old, well-established manufacturer. Bryston has been an
important producer of home and professional audio components for
more than 40 years. While they have always produced upscale equipment,
their most recent designs will appeal to the high-end consumer.
To qualify this, high-end here doesn¹t spell high price as
all of the components are priced rather reasonably. Now let us
explore the merits if the component under review as we begin with...
Appearance:
Based on size, it is difficult to imagine that
the BP-25 accommodates the circuitry of a preamplifier as well
as a complete digital to analogue converter. The unit is only
1 3/4 inches high, 10 inches deep or optional 19 or 17 inches
wide. However, the external power supply, (connected with a detachable
umbilical cord) is a welcome addition as it provides the necessary
voltages in isolation from the main unit¹s circuitry, regulating
controls and, in this model, the DAC.
The controls in the unit¹s silver or black
face plate are logically arranged and include (from left to right)
a tape monitor toggle switch, another toggle to select DAC 1 or
2 inputs, a rotating selector switch for seven inputs (including
two balanced). The balance control is centered, followed to the
right by the volume control, a polarity toggle (for absolute phase)
and the mute toggle. The unit¹s on/off switch is located
on the power supply. The rear panel accommodates all inputs including
two pairs of XLR (balanced), two sets of RCA and one set of XLR
outputs. All in all, the BP-25 DA is an unpretentious unit with
sufficient style to be pleasing to the eye.
Technology:
A lot of changes have been implemented since
we last looked at a Bryston preamplifier. Technical features and
improvements include reduced intermodulation distortion which
is now less than .0015% from 20Hz to 20kHz. The noise floor has
been improved, reducing background noise far below audibility.
Crosstalk is essentially eliminated, thus preventing spurious
leaking from one channel to the other and decreasing signal bleed-through
from one source to another. Components plug directly into glass-epoxy
circuit boards, eliminating variations in signal travel and wire
interaction. Signal switching and audio connections utilize heavy
gold plating to provide long-term trouble-free connections. Gold
plated balanced and unbalanced input and output connectors are
standard. A 12 volt AC/DC screw terminal connector on the rear
of the power supply provides for a convenient remote start feature
available on all Bryston amplifiers.
BP-20/25 series preamplifiers boast steel housing
to reduce unwanted electromagnetic interference. The unit¹s
buffered inputs provide optimum electrical isolation, thereby
lowering distortion and improving linearity from source components.
For those who live in electrically polluted environments, Bryston
provides a ground plane in this new design which helps to further
reduce cross-talk and noise throughout the internal circuitry.
As mentioned earlier, the power supply is located externally,
mainly to eliminate transformer-induced noise. All in all, the
new preamplifier is a well executed design, with attributes usually
found in more expensive units.
The DAC used here is the top of the line device
made by Crystal (CS43122), but quality controlled and hand-selected
by Bryston to ensure consistency. The oscillator clock is also
hand selected, but the DAC¹s most important element is the
care bestowed upon the analogue output stage. It¹s based
on a proprietary, discrete, patented Class A design with separated
op amps and may well be responsible for the unit¹s heighten
performance, as we shall see later. The DAC offers 24-bit word
capability with an input sample rate from 16kHz to 108kHz. Our
sample preamplifier specked out at 0.00107% distortion with a
signal to noise ration of 105.71dB unbalanced and 101.23 balanced.
The Sound:
We used the preamplifier with the Bryston 7B-SST
monoblocks (reviewed in Vol. 15 #3), the Exposure power amp (reviewed
in this issue) and the Wyetech Labs Onyx monoblocks (reviewed
in Vol.13 #4). All wiring was completed with Nordost¹s new
Valkyrja cables reviewed in our last issue. Source components
included the Audio Aero Capitole CD player (reviewed in Vol. 15
#2), the Musical Fidelity TriVista CD player reviewed in out last
issue and the German-built Accustic Art player to be reviewed
in our next issue.
To test the preamplifier¹s DAC, we connected
the digital out from the players to the DAC¹s input and connected
the CD players directly to a couple of the preamp¹s inputs.
This allowed us a direct and quick comparison between Bryston¹s
and the built-in players¹ DACs, by simply switching inputs.
Having played back some of our 'difficult' well produced CDs,
we found that sonic differences were nowhere near as dramatic
as we had expected. To our utmost surprise, the Bryston DAC performed
almost identically to the Audio Aero's $13K player. As the transport
was identical, the slightly different sonic attributes relate
directly to the DAC. Compared with the Audio Aero DAC‹a
Swiss design by Anagram‹the Bryston sounded a little more
matter-of-fact, a little dryer. However, the fundamental sonic
signature of these DAC's was almost identical. Whereas the Audio
Aero allowed additional harmonics to 'blossom', the Bryston limited
the scope of harmonics, but provided enough musical finesse not
to cause concern. Astoundingly, the Bryston DAC finished high
frequency information almost identically with that of the Audio
Aero. Spatial information, imaging, focus on instruments and voices
were outstanding‹so much so that our regular listening panelists
often could not identify which DAC was being auditioned. Comparing
the Bryston with the Musical Fidelity DAC resulted in similar
differences. The Musical Fidelity SACD DAC did 'extract' more
harmonics, but resolution wasn¹t as complete as with the
Bryston. Whereas the MF has an overall 'sweet' sound, the Bryston
is more businesslike, less seductive, but quite faithful to the
music.
Synopsis & Commentary:
We expected the BP-25 to be quite good and
thought that its DAC would be in line with the quality of the
preamplifier. We did not expect the unit to perform high-end tasks
almost matching the performance of CD players in the mega-buck
ranges‹but it did. According to Bryston, the feat was accomplished
with proprietary Class A discrete operational amplifiers, well
separated, discrete analogue stages and some important circuitry
improvements mentioned earlier.
It would be unfair to ignore the BP-25¹s
function as a preamplifier; we feel that this current model outperforms
the earlier units by far when it is employed in a system with
various components. The older models performed very well when
used with Bryston components, but fell short of being 'great'
when used in high-end systems, assembled with electronics from
different manufacturers. The new BP-25 is a killer preamplifier
and our conviction is based on an industry standard that takes
price and performance into consideration. As we all know, the
law of diminishing returns applies here more than in other industries
and it is refreshing to find a reasonably priced component that
performs way above similarly priced units. We believe that this
is Bryston¹s best ever preamplifier and a great component
to use with any audio system configuration. The DAC is another
excellent component and is likely better than the ones used in
most mid-priced CD players. Folks who wish to upgrade their digital
playback system can use Bryston¹s up-to-date DAC by connecting
it with a good digital cable directly to the CD player¹s
digital output. Those who are about to buy a new CD playback system
are well advised to look for a good transport, such as the German-made
Accustic Arts Drive 1. This system combination leaves nothing
to the imagination and performs accurately and musically.
Addendum: Owners of older BP-20
or BP-25 preamplifiers can have them upgraded to the present model
which includes a new face plate and the external power supply.
As well, the DAC can be accommodated in older preamplifiers at
a cost of about US $1,000.
Ernie Fisher - The Inner Ear Report
www.innerear.on.ca
We invite you to experience the Bryston SST2 Series amplifiers
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