Well, this is likely the fifth generation of the 7B model I have auditioned and reviewed over the past couple of decades and I expected them to sound at least similar to the previous models I had in-house for a few years. I recall how, over the years and model changes, Bryston’s amps have improved steadily, but maintained a good part of their sonic personality/signature — so they should indeed sound similar. They don't. In fact, I didn't think it possible for two —actually four — amplifiers from the same company to sound quite different!

These are very powerful solid-state amplifiers with excellent build quality and with phenomenal specifications. They are single channel amplifiers, and I quote — “virtually perfect from overload on any type of loudspeaker”. Each amp will put out over 600 watts into an 8-ohm load, (900w into 4 ohms). They are equipped with single-ended (RCA) or balanced (XLR) inputs, an active low distortion buffer and selectable gain at 23 or 29dB. These specs are complement by regulated, beefy power supplies to all voltage gain stages. Harmonic distortion is quoted as 0.005% (from 20 to 20kHz); noise below full output is -113 single ended and -116 balanced; slew rate is 60 ms; damping factor is>300 at 20Hz. All this may be meaningful to the technically savvy, but for me they are but one part — a guide perhaps — because I respect and accept scientific testing and specifications where results show to correlate with what I hear. I hold that science is not yet able to accurately evaluate all parameters of sound.

Anyway, here is on of the most interesting parts of the technology used in the Cubed Series designs. All incorporate a new circuit design of the input stage — the "Salomie" input stage, named after its designer and patented by Bryston. Bryston states that this new input stage is more linear than that of any amp they had produced before this series. Among this new circuit’s attribute is a lower noise floor which may be responsible for the amplifiers’ knack to extract musical subtleties, not heard in many other SS design, of which I know. The Cubed 7Bs are built like proverbial battleships and boast the kind of attention to detail that makes most high-end audio equipment outrageously expensive. That is, of course, until we consider that most Bryston amps are still operating 20 years after other real high-end phile equipment has surrendered to terminal parts disorder.

For a lot more information simply click on http://www.bryston.com/products/power_amps/4B-3.html

THE SET-UP
I used a Wyetech Labs Ruby preamplifier, because I value its neutral sonic disposition, which allows the amps and source components to work at their best. A Bryston DAC and Digital player were the source components, though I also used a Magnum tuner to warm up the system. Cables were from Nordost and included the TYR 2speaker cables and the Norse interconnects as well as power cords.

My permanent loudspeakers are from Leo Lewis of Ethera Vitae fame, and I have used these off and on for a couple of decades; found them sonically refined and especially revealing (used them almost every time when reviewing cables). As of the last 10 years, or so, I have used and compared them to much high priced speakers (up to $20k), but have yet to find some that will outperform them in all but the lowest bass. My listening material is what I favour — the classical, including large orchestral works, the jazz and the blues — have a mean collection of well-mastered music.

THE SOUND
The 7B-3 are only the second solid-state amplifiers whose extreme high frequencies can be favourably compared with the best I have heard from tube amps, the other being the recently auditioned, German-made T+ A. However, both of these SS amps haven’t quite the somewhat embellished sweetness of the best tube amps and are, instead, on the (more realistic) drier side. The 7Bs haven’t a pinch of roughness or glare in the high end, making them some of the smoothest-sounding high-powered amplifiers that also boast plenty of dynamics. Few, if any, amps will surpass them in terms of completely unstrained openness and musicality. I daresay that these amplifiers rank in the top category of the most neutral-sounding power amps of which I know.

The highs and midrange segments of the frequency spectrum are neither forward sounding like so many SS designs, nor recessed like many tube amplifiers. They are not quite as refined as one or two extremely high-end amplifiers, but then again they don’t cost like them. The midrange — from about 160 to 1400 Hz — is an important part of music but must blend inaudibly with the range for the mid highs. That is from about 2,000 to 5,000 Hz — and this is where the Brystons perform almost perfectly, introducing delicate texturing along with harmonics and this quality may well be the reason why the system involved me with its ease of listening throughout all of my tests.

Detail and resolution of delicate musical nuances are excellent, while the soundstage width is very well rendered with depth and perspective well presented. Imaging — the representation of multi-dimensionality on a sound stage is not merely good, it is superb and outperforms Bryston’s most recent predecessor I had in house earlier — and that isn’t easy.

Bass is excellent: deep, tight, and very well controlled, but not quite as resolute as that from the older 7Bs. This is not to say that the older version will do a better job of reproducing low end on all loudspeakers. The new 7Bs will likely do best with full-range loudspeakers that can manage low frequencies down to 30Hz, no matter what efficiency rating. My own Ethera Vitae reach down to 42Hz, but did wonderful things below that point, probably benefiting from the amplifiers’ capability to deliver more than sufficient harmonics. In other words, I didn’t miss bass, even when I played back music from pipe organ recordings.

CONCLUSION
I should tell you that I am not a SS or a vacuum tube advocate and enjoy both technologies — I like the transparency, precision and control of good solid-state amps, but quite understand and often enjoy the euphonic elements and musicality of well-designed tubed components.

Overall, the 7B-3s are probably as delightful-sounding as any amps I've auditioned. They are completely without a familiar sonic signature, yet immensely melodious and transparent, and absolutely effortless in reproducing the kind of dynamic range one may get at live performances of large orchestral music.

The improvements to the amplifiers’ sound quality are not subtle, and I regard them as delicate sonic enhancements noticeable across all performance attributes such as highs, mids, lows, imaging, focus, dynamics — well, I guess, covering pretty well all the elements we in the business use to explain the unexplainable with phile jargon— the sound of things audio.

Here, then, is an amplifier that can hold its own, overall, with anything else in its and higher price class; it will work best with speakers that are neutral through the mid-range, well extended and with smooth, detailed high frequency characteristics. It’s my guess that the 7B-3s will handle all difficult speaker loads as they can put out as much as 650 watts into 8 ohms, double that into 4 ohms. Those of you who are questioning the need for this awesome power need to remember that there really isn’t an amp with too much power; same as there isn’t an amp with too much fidelity. The Cubed 7Bs sound better than any low-powered SS amplifier I have ever heard, even at low listening levels.
These amplifiers may not be the world’s best, but they are at the very least world-class amplifiers, better than Bryston’s preceding amplifiers, as well as many of their competition. The may not be inexpensive, but they do cost a lot less than what hi-end audiophiles have been paying for amplifiers that may not be anywhere as good.