Bryston 4B SST² C Series Amplifier

2014-05-19T13:15:34+00:00February 1st, 2011|2-Channel Amps, Preamps, Reviews|583 Comments

Unlike most audio components, a power amplifier doesn’t have to look beautiful. You can always hide it out of sight. That doesn’t stop some manufacturers from lavishing exquisite looks on their power amps to match the rest of their range. Think Nagra, Classé Audio, Krell, Esoteric or Accuphase. You’ll pay for the privilege of course. Many of us don’t buy our components from a single manufacturer, so matching cosmetics may not be a consideration.

Bryston on the other hand has never been prized for fit and finish – it’s what’s inside the box that counts for them, and that helps give the company a competitive edge in the value department.

Bryston started out making amps for professional users – big black rack mountable devices with enormous front handles. They still make them, but these days you get a choice of rack mounted 19-inch units or more conventional looking 17-inch units without handles. You can even choose a black or silver finish, and the front panel is sculpted and features the maker’s name in bold relief. Not too shabby. Still, they won’t be giving the Japanese designers any heartache on the aesthetics front, but they won’t look out of place in any modern system anymore.

Another standout feature of any Bryston amp is the incredible warranty that comes with it – 20 years. That speaks not only of high quality parts carefully screwed together, it also indicates that parts are run well within their capabilities and not pushed to the limit. Nobody puts a 20 year warranty on something they suspect won’t go the distance. There are enough satisfied Bryston customers around to attest to this longevity, and to the excellent service they get if ever a problem does develop. The original 4Bs came with a 5 year warranty but they proved so reliable, still performing within specs at the seventeen year mark, that Bryston quadrupled the warranty and made it retroactive to boot.

So why didn’t we all go out and buy a Bryston amp? They certainly offer a wide enough range of power outputs. Well frankly, the reputation Bryston holds for durability was not always matched by their reputation for sound quality amongst audiophiles and the audio press. People looked to Krell, Mark Levinson, Classé Audio or to tube manufacturers like Acoustic Research or Conrad Johnston for the best sound and labeled Bryston with the less than complementary label of professional.

So Bryston set about improving their products – not by making them bigger but by making them better.

Let’s go back to the beginning. The 4B, mainstay of the Bryston range, first saw the light of day in 1978 and has been through 6 redesigns since then. The first two models were just called 4B, then came 4B E, 4B NRB, 4B ST, 4B SST and now 4B SST² (squared).

The first model with audiophile pretensions was the ST, and it caused audiophiles to sit up and take notice. Designed by Stuart Taylor in the late 90’s, the 4B ST was almost a total redesign. Its highlights included lower power supply impedance, increased energy storage, improved transformer layout, shortened leads, improved signal isolation and a new input buffer amplifier.

After selling over 30,000 4B ST amps, in 2002 Stuart refined his design into the even more powerful 4B SST, with lower distortion and improvements at both frequency extremes into the bargain. This update included faster, more reliable and linear output transistors, doubled filter capacitance for more controlled bass, new proprietary grounding protocol and a new computer modeled heat sink for better cooling.

We at CANADA HiFi reviewed the 4B SST at the time and found a lot to like about it.

But Bryston does not rest on its laurels, and the newest update of the C Series is a big leap forward again, propelling Bryston into the audiophile stratosphere, stunning even Absolute Sound’s Harry Pearson into superlatives. So what did they change this time? For starters there’s a new power supply transformer design, a new chassis design, a new soft-start circuit, a new balanced input stage and a new power supply board. Other enhancements include a bridging mode performance improvement, a reduced point top point wiring a reduced circuit board count, redesigned output chokes and a new push on-off power switch.

You’d think they be running out of things to improve after thirty years, but to be fair, this is only Stuart Taylor’s third crack. You can actually see the schematics for the 2002 design on line at the Bryston website, but they haven’t been so generous yet with the new model, in case you were thinking of building your own.

So what are the features of the current design? Start with fully discreet components, carefully selected and tested, and then hand soldered using a proprietary quad-complementary topology. Bryston claims that this design virtually eliminates aggressive high harmonic distortion products, producing a sound akin to pure class A but with lower overall distortion levels and less heat. Each channel has its own power supply based on a massive toroidal transformer. Unusually, each unit is burned in and stress tested at the factory before shipping, and comes with a set of measurements to confirm it has tested within specs. The unit in front of me, SN 005021, measures better than spec on every measure.

The Bryston 4B SST² has a power rating of 300 watts per channel into 8 ohms, 500 watts per channel into 4 ohms and 900 watts bridged into 8 ohms. It retails for $4550.

Never mind all the technical stuff. What really matters is how it sounds. I’ve had many amps through my listening room over the years, but the 4B SST² draws the least attention to itself of all I’ve tested. It just disappears and adds nothing of its own to the music. No hiss, no hum, no distortion, no peaks or valleys in the frequency response that I could detect. It makes for a rather dull review I’m afraid, but the music isn’t dull. When there’s sparkle in the recording, you’ll hear it, when there are 100 instruments playing at once, you’ll hear each one in its rightful position. Best of all is the overall sense of ease, that the amp is not breaking a sweat when you put the pedal to the metal. Music should just flow effortlessly like it does live.

The 4B SST² plays no favourites when it comes to your choice of music. I tried a wide range here – even spoken voice. Nothing trips it up. The perspective is a little further back than the Perreaux Radiance that has been my constant companion for a number of years, giving a wider soundfield and more precise sense location of the instruments. Moving from the Perreaux to Bryston is a bit like the going from CD to SACD. It’s less immediately impressive but truer to life and more musically engaging. It’s a very fast amp but it doesn’t slam you with its sharp leading edges. There’s simply more detail, more subtlety and ultimately, more meat on the bone.

You will need the right kind of equipment to go with the Bryston if you want to experience this level of performance. I’m using an EMM Labs SACD Player, Parasound Halo JC1 preamp and Wilson Benesch Act 1 speakers tied together with Nordost Valhalla cables, all known for their transparency and minimal distortion. I’ve also used Atlas Mavros cables and a bunch of different and more modestly priced speakers, and the 4B SST² has always proved the perfect partner. It’s entirely unfussy, and surprisingly sprightly and resolving for such a powerful amp. Did I tell you it’s rated at 300 watts per channel into 8 ohms? That and the high damping factor make it suitable for a wide range of speakers, although there are some inefficient low impedance speakers that the Bryston is not optimally suited to drive. You may want to look somewhere higher up the Bryston range or to another manufacturer altogether in that case.

So are there any weak spots to report? Amplifier design is always a matter of balance between competing objectives and the choices made here while working well for a wide range of tastes and applications are by no means universal. Some may miss the added midrange presence and warmth of a top flight tube amp, while others will prefer the kick-ass bass of a Krell or Mark Levinson. And yes there are better amps out there, but none I’ve heard leave this one far behind and none come close to the value proposition on offer here.

If you’re looking for physical beauty, look elsewhere. But take this one home if you want a modestly priced powerhouse amp with high levels of detail and refinement that will keep on tickin’ till your ears give out.

Bryston Limited

Bryston 4B SST² C Series Amplifier
Price: $4550 CAD

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