Authorized Reprint from

The Bryston BP25

Pre-amplifier and

14B SST Power Amplifier
by Chris Binns
Looking back, there are certain hi-fi products I have owned that I regard with a degree of affection, and regret getting rid of. One such example is the Gale GS 401 loudspeaker. In my estimation, they were surely the most elegant piece of hi fi equipment ever made, and this might go some way to explaining the enormous lengths that I went to in order to get them sounding good. Due to their inefficiency and cruel load they were apt to destroy amplifiers on a regular basis, and if that sounds surprising don't forget that this was 1977 and amps were not what they are today. To make matters worse it seemed to me that the 401 only began to work properly when you wound it up, which suited my musical tastes if not my neighbours. But finding an amplifier that sounded good while being capable of sustaining this kind of abuse was proving to be no easy task - the Naim 250 sounded great, but used to thermally shut down after half an hour or so of loud music.

The world of professional amplification wasn't much help either. At the time, the heavy weight contenders that were most often seen in recording studios were the Amcron DC 300a and BGW. Designed to be bomb proof, and withstand the antics of bored engineers (putting 9" of solder across the output terminals and turning the volume up.....) they could certainly deliver masses of power all day long, but must rank as some of the most musically dull and uninteresting amplifiers that have ever existed.

And then I encountered the Bryston. A friend of mine had purchased a power amplifier in the states and brought it back with him, and a session with the Gales suggested that here was an amplifier with all the right credentials for professional use, but with a dynamic and musical performance to boot. As luck would have it, London hi-fi retailer KJ Leisuresound had obviously reached a similar conclusion and started bringing them in to the country so I ended up buying a 4B power amp. Big, black and ugly there was nothing externally to distinguish it from any other large professional amplifier.

But its sound quality was streets ahead of the competition, and it suited my requirements perfectly. I've still got it. Although no longer in the front line of my hi fi system, it has come to the rescue many times when the situation has necessitated a powerful amplifier. Sadly, that has included the indignities of being used for everything from studio monitoring through to the odd PA, and as such it enjoys the accolade of surviving the fateful task of amplifying my voice in the heady days of my singing career. The Bryston has been through every torture possible, with never a squeak or blown fuse of compaint.

But get this. The guarantee only ran out last September. Twenty years! If that doesn't inspire confidence in a product, nothing will.

Now distributed in this country by PMC loudspeakers, there has been a gentle but painstaking evolution based on the original models introduced over twenty years ago. The objectives then were to produce amplification that would drive any loudspeaker with great accuracy and very low levels of distortion, a challenge that continues to preoccupy the company to this day. This must in one respect make Bryston pretty unfashionable in the hi-fi industry where technical measurement would seem to have gone by the board, and judging by the success of SET amplification, low distortion is not a priority. But, for once the recording industry's continued fascination for specification first, sound quality second has at least worked in its favour and means that the Bryston has been accepted with open arms, and is used extensively by many large studios such as the Townhouse in London. Which traditionally of course, is no recommendation for a hifi amp.

For review I actually received not just a power amp but a pre-power combination. The BP 25 is a straight-forward remote controlled pre-amplifier with an integral MM/MC selection stage and five line inputs, two of which are balanced. One tape loop is provided, while remaining controls are for balance, MC/MM selection, mute and phase invert. The moving coil input is based around the use of transformers rather than an active section, which means that load adjustment is not available. The remote control caters for volume, mute and phase, and although the buttons feel a bit tacky it works - for once with a decent range and acceptance angle. Good quality connectors are used, while the power supply is housed in a separate box that can be sited away from the main unit and left switched on. Slim and elegant, the BP25 retains just enough oh its professional heritage to look functional, and is available in silver or black.

The 14B ST is something of a lump. An elegant purposeful looking lump however, the silver front panel bereft of any controls save the touch sensitive switch that activates the unit out of standby. Two led's turn from red to green after a few seconds and indicate that the unit is ready for use, in the unlikely event that you manage to drive the amplifier into clipping, they will flash red. If, heaven forbid they go to orange, it is either the end of the world or the amp has thermally shut down. Large heatsinks run down either side of the unit, and the back panel carries the power/breaker switch, balanced and unbalanced inputs and a single set of hefty output terminals. Useful additions include remote standby switching from a pre-amp and a selectable extra 6dB of sensitivity on the balanced input.

Internal construction is to a high standard, and is effectively a dual mono design, where each channel consists of two power amplifiers in a bridge arrangement, fed from its own massive power supply. The ST suffix on the Bryston power amps refers to designer Stuart Taylor, who has re-engineered the layout around new Motorola bi-polar output devices to even further reduce noise and distortion. The 14B is unusual in that despite having it powered up, under quiescent conditions the heat sinks remain cool to the touch, and it takes half an hour or so of actually playing music for the output stage to reach its operating temperature and thus realise its full potential. Which, of course is quite considerable, just in terms of its prodigious output capabilities. With 500 Watts available into 8 Ohms and nigh on a Kilowatt into four, this must rate as one of the biggest amplifiers I have used in a domestic system. So what? The days in which this kind of thing impressed me have long since gone (really...) and there are aspects of an amplifiers performance that I value far more, most of which seem to bear no relation to measured performance. So it was quite easy to be patient and let the brand new Bryston combination run in for a couple of weeks.

Where to begin? The BP 25 seemed to be equally at home with CD or vinyl, while the internal phono stage was good enough to not have to think about a separate unit. Compared to the Pass Labs Alepl Ono (itself the price of the Bryston) it was characterised by a warmer sound, with slightly less definition and apparent detail, but held its own very effectively with rhythm and pace.

As a relatively long term user of valve amplification, when I get to listen to a large solid state set up in my system the first thing I notice is the quality of the bass, where traditionally superior current delivery and control come in to their own. Closely followed by frustration at the curious inability of most large amplifiers to project music away from the loudspeakers to allow for a more intimate connection with the music. Well, score one for the bass performance, which is the best I have ever heard coming from the Primary monitors. There was a coupling here that allowed incredible grip, speed and dynamics, with an extension that revealed hitherto unexplored depths. In particular, kick drum was conveyed with incredible precision and lack of overhang, allowing you to hear all other bass information without any smearing and thus startling clarity. The Bryston had the loudspeakers well and truly in its grip and wouldn't let go, regardless of level or program material.

What I didn't expect was everything else. With such a firm foundation to build upon, mid and top performance was clean, detailed and articulate, indeed, as it should be, but there was that wonderful elusive quality that allows music to wrap itself around you and demand your full attention. So far, most of the squeaky clean variety of high power solid state amplifiers that pass through my living room have singularly failed to achieve this, and ultimately have left me unmoved with their performance. Not unrelated to this is a lack of discrimination over listening levels - the Bryston system allowed probably some of the loudest sustained listening sessions I have had, with no apparent restrictions on dynamics, apart from potentially blowing up my loudspeakers. But despite its heroic capabilities, it doesn't have to be operated at full tilt, and is quite capable of providing a musically satisfying performance while keeping the dynamic envelope intact at more modest levels, much to the relief of the rest of the household.

But I couldn't help turning the wick up while listening to some old Traffic albums, in particular John Barleycorn Must Die which still stands as one of the greatest arguments for analogue recording circa 1970. The sound of the drums, in particular was so real as to be an embarrassment to many modern recordings, and despite owning this record for nigh on thirty years, I think this is the most exciting I have ever heard it. It goes without saying that there then followed a night of extreme nostalgia for which I offer no excuses - I thoroughly enjoyed myself.

But the Bryston also has the capability of being subtle when required, revealed in all its glory when playing string music. Playing a new recording of Gerald Finzi's Cello Concerto on Naxos demonstrated a wonderful range of tonal colour and texture, rich and full bodied, without the rather bleached emaciated quality sonic solid state amps possess.

The Bryston does everything I would expect from a high quality solid state amplifier. If that sounds like a guarded statement, it is - but I will go on to say that it is also one of the very few designs that has managed to turn my head away from valve amplification. The combination of that fluid and engaging quality with no apparent restriction of the operating envelope forms a temptation that I find difficult to resist.

So there we have it. An amplifier with a spectacular specification, which for once hasn't resulted in a technically marvellous but musically boring and uninvolving product. And if the thought of an amplifier with a professional heritage starts to ring alarm bells, turn them off. For once you can have your cake and eat it. And bear in mind that there is a good chance that the next disc you buy could have been mixed on a Bryston amplifier.