BRYSTON 4B POWER AMPLIFIER
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BRYSTON
4B³ Reviewer Edgar Kramer
POWER AMPLIFIER
078
C
anadian audio specialist Bryston is one THE EQUIPMENT
of the few companies successfully Aesthetically, the 4B³ is a alarmingly austere power
treading both the professional and amplifier design, almost a by-product of that build quality.
consumer audio spaces. Surfing both The solid machined aluminium grooved fascia (black or silver
waves is not always easy — the two available) presents an expertly anodised finish. Machined
camps are not always aligned. etchings display the company logo and the amp’s model
Yet they ultimately share a common goal — the number just above a central on/off switch which engages
reproduction of music with accuracy in all aspects of sonic after operation of the circuit breaker style mains switch
performance. And other aspects can satisfy both tribes of around the back. Two tiny green LEDs inform you the
users — such as Bryston’s reputation for building amplifiers amplifier is active. Switching on the amp starts a series of
which are reliable, indeed indestructible (an industry-leading relays and soft-start circuits that produce a short string
20 year warranty is an unambiguous statement). Who’s of rather cute-sounding effects — I enjoyed hearing that
going to object to that? pre-music-session electronic ritual every time.
079
BRYSTON 4B3 POWER AMPLIFIER
SPECIFICATIONS The rear panel is well laid-out and provides The 4B³’s input and filtering stages are based
all you’ll need from a power amplifier. Inputs can on Bryston’s patented low distortion circuit,
BRYSTON 4B³ AMPLIFIER
be switched to either XLR or RCA, while speaker designed by respected engineer the late Dr Ioan
RATED POWER: outputs feature good quality binding posts. (My Alexandru Salomie. Bryston has designed a stout
300W into 8 ohms; 500W only gripe would be that the spade openings are regulated power supply featuring two large
into 4 ohms; 900W into located at the top of the post, rather than the stacked toroidal transformers rated at 540 watts
8 ohms (bridged mono) more common top-and-bottom provision, so that each, a capacitor bank with 80,000μF of storage
HARMONIC DISTORTION: inserting very stiff large-gauge spade-terminated and eight bipolar devices per channel. The 4B³
≤.005% from 20Hz to 20kHz cables may leave them sticking up above the should drive just about any speaker you can
at 300W amp’s top panel line in an unsightly manner.) imagine with authority (my Wilson Alexia’s near-
NOISE BELOW FULL A small switch toggles between normal 1-ohm dip in the bass is a strong case in point).
OUTPUT: -110dB single operation and bridged mono, while a further
ended, -113dB balanced semi-recessed switch controls either ‘local’ PERFORMANCE
SLEW RATE: >60V/µS operation or activates a terminal for remote And that is where this amplifier’s performance
POWER BANDWIDTH: switching via an external component. There’s a story should start. The 4B³ is a control freak in
0.5Hz to >100kHz standard IEC socket for the provided cable. terms of grabbing hold of your speakers’ drivers
DAMPING FACTOR: Lastly, we have a feature that more amplifier and maintaining bass control, depth and power
>500 at 20Hz (8 ohms) manufacturers might consider, in our view. The (the high damping factor of 500 at 20Hz at 8
SWITCHABLE GAIN: amp can be switched to a choice of two gain ohms will have a big role to play). Add to that
23dB or 29dB settings where the low setting provides 23dB list superb detail resolution too. Kai Eckhardt’s
DIMENSIONS (WHD): of gain and the high setting 29dB. This is an filigree bass lines on Brenda from Curandero’s
432 × 160 × 395mm extremely useful option which can provide better ‘Aras’ are remarkably nuanced and agile while
WEIGHT: 28.6kg preamplifier matching where a passive unit may possessing tremendous attack when required,
WARRANTY: Twenty years require the higher gain setting and, conversely, a especially towards the end, where very low bass
from date of manufacture high-gain active preamplifier may be best suited notes, harder to reproduce, are introduced as
PRICE: $7899 to operate via the low gain switch. This goes a track closers — no problem here. Ditto with
CONTACT: Busisoft AV long way to alleviate excessive noise issues in staple reference track Sergio Leone from Jackson
on 03 9810 2900 cases where there’s too much system gain — a Browne’s ‘The Naked Ride Home’, where the
www.busisoft.com.au high-gain valve preamplifier, perhaps — or to subterranean bass drones mid-track are superbly
help kick along a struggling passive preamp or controlled, and extremely deep. Large floorstand-
maintain a direct-feeding DAC at higher output ers or subwoofers are essential here to appreciate
THE SMALL CENTRAL SWITCH levels in order to avoid bit-stripping. this almost scary phenomenon.
TOGGLES THE 4B3 BETWEEN NORMAL
OPERATION AND BRIDGED MONO.
080
BRYSTON 4B3 POWER AMPLIFIER
BRYSTON HAS DESIGNED Low frequency prowess is one thing, but the instrumental strands. The Los Angeles Guitar
A STOUT REGULATED 4B³ manages, nevertheless, to remain superbly Quartet (LAGQ) self-titled release illustrates this
POWER SUPPLY
FEATURING TWO LARGE
balanced. Some amplifiers have tremendous strongly, with four distinct guitars and percussion
STACKED TOROIDAL bass power that comes at the expense of some in Djembe, the second movement of The African
TRANSFORMERS, A midrange clarity. Not this one. The Bryston sounds Suite individually placed in tight focus on a large
CAPACITOR BANK WITH evenly capable throughout its wide 0.5Hz to soundstage. When guitars and drums play in
80,000ΜF OF STORAGE
AND EIGHT BIPOLAR
100kHz range — no exaggerations or omissions at unison, all can be either appreciated as a musical
DEVICES PER CHANNEL. any portion of the frequency band. whole or each followed individually to fully
Neutrality is a strong feature on the 4B³’s appreciate each musician’s skills.
comprehensive menu. This amp Bryston’s amplifier is rather good at presenting
is neither warm nor sterile and accuracy in tonality, too, with acoustic instruments
certainly never syrupy — nor, sounding lifelike, present and delightfully
conversely, brittle. In fact, the realistic. The 4B³ is capable of very good dynamic
best descriptor for the 4B³ expression with explosive tracks such as Whipping
(and strictly speaking for any Boy from Ben Harper’s ‘Welcome to the Cruel
quality amplifier) is neutrality. World’, where the shades between the slow guitar
The 4B³ is a If you like spices with your music,
they should be condiments
intro (with all its microdynamic metal-string detail
beautifully rendered) and the subsequent blast
control freak in added via other components,
the amplifier should reproduce
of snare and bass guitar is neither truncated nor
diminished in any way.
terms of unaltered signal.
Of equal importance is CONCLUSION
grabbing hold of resolution and separation, A well-designed solid-state amplifier should fulfil
your speakers’ aspects of reproduction that
can challenge some lesser
the purest principles of music reproduction,
accepting the input signal, then transparently
drivers and solid-state amplifiers. The 4B³
excels in reproducing low level
and harmlessly delivering it to the transducers
regardless of their inherent electrical demands,
maintaining bass music cues required for the
best high fidelity ‘virtual reality’,
providing effortless and tight control of the drivers
while manifesting boundless dynamic expression,
control, depth while clearly delineating detailed resolution and accurate tonality. In the
busy compositions into 4B³, Bryston has covered all these bases covered...
and power. easily discernible individual for at least 20 years.
081
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