The Karan Acoustics KA M 650 Mono-Blocs

Little Big Man…

The Karan KA M 1200 mono-blocs have been something of a fixture in the Gregory listening room for some considerable time. A welcome presence with their commanding musical authority and bottomless power delivery, I’ll not deny that at times it has felt a little like sharing the house with an autocratic and unbending dictator. Not only are they extremely large, they’re also heavy enough to be completely unmovable without two, strong men; both factors that help explain why they stayed for so long. That and the sublime results that rewarded the considerable effort of wrestling them into place. Absolutely intolerant of any careless or incautious act on the part of the user, well over a kW of power into 8 Ohms is easily capable of administering rather more than a slap on the wrist in instances of operator error, one piece of particular stupidity actually vaporising a driver voice coil; there was literally nothing left! But then, if you take a genuine monster home and get careless, you’ve got to expect to lose a few members of the family…

The thing that makes the 1200 worth all the physical effort and personal discipline that it demands are the musical results it produces. So many big amps grip the music so tight you feel that they never let go. With the Karans they grip the acoustic space, holding it totally stable yet allowing the music a wonderful, unconstrained expressive freedom within it: no limitations on headroom, no congestion or confusion, phenomenal resolution and separation of musical detail. Yet all of that from a preternaturally stable perspective; it’s a remarkable performance and for anybody lucky enough to be able to afford these amps, install them and then simply enjoy them they constitute a fabulous option. But within the constantly changing landscape of a reviewer’s system, the practicalities involved weigh nearly as heavy as the amps themselves, so the feelings of regret when they finally departed were tempered with an almost guilty sense of relief. That and the knowledge that waiting in the wings were Karan’s KA M 650s.

Built into the same chassis as the company’s KA S 270 stereo amplifier, the 650 still presents a pretty imposing block. The difference is that at around three-fifths of the cost and two-thirds the size of the 1200 it is rather more manageable (in every sense). Indeed, at a “mere” 50kg it is just about man portable – a comment that will have chiropractors everywhere rubbing their hands in glee. Attempt this and be warned that you are solely responsible for the consequences. Physical parameters aside, the KA M 650s are exactly what you’d expect: the same bluff but beautifully executed casework (including the same hand lacerating heat-sinks), the same fully differential, DC coupled, zero feedback circuitry, the same balanced or single-ended inputs. You of course also get the same captive isolators built into the feet, three of them ensuring the amps get a firm and mechanically close-coupled footing. Inside the packed casework of each chassis is a pair of 960 VA toroidal transformers and 132000 microF of ultrafast reservoir capacitance, feeding the sophisticated ring emitter bipolar output devices. Those huge heat-sinks aren’t just for show; with the driver stages running in class A and the output stages leaning that way, the amps run warm, even in the depths of winter, where they act as pretty effective supplementary space heaters. One other aspect of the 650s adds to their practicality over the 1200. Each amp requires but a single IEC mains lead as opposed to the excessive demands of the larger model, a factor that certainly makes providing a coherent mains supply significantly easier.

The watchword with the 650s has to be “care” – as in “handle with”. Yes, they are physically more manageable than the 1200s but in every other respect they are just as critically revealing. Cable differences (I ran them with Crystal Ultra, and Nordost’s Odin and Valhalla) are shockingly apparent, as are housekeeping issues like the provision of a clean earth and proper support. It’s not that they sound bad without these niceties; the worst you can accuse them of is sounding a little flat if they’re not being fed their preferred diet. But playing with cables, the finite elemente amp stands, even the connection order and polarity of the mains leads into the distribution block all elevate the performance from the merely excellent to the musically spectacular.

There are two inevitable questions confronting the 650s: how do they stack up against the 1200s, and how successfully do they juggle the big amp issues of control versus musicality?

Let’s start with the second of those. There’s a real danger with seriously powerful amps that designers and listeners get seduced by the attractions of high-definition, the ever more detailed and clearly defined depiction of each and every element of the recording, be it an instrument, the acoustic, the nature of the floor or a door opening in the auditorium. It’s an understandable tendency simply because these are real, tangible differences in performance: you can hear the space around a player or you can’t, you can identify a music stand scrape or the subway rolling underneath or they’re simply unintelligible noise. But the fact that we can hear these things doesn’t actually mean that an amp is working better, just differently. The danger is that in defining the particular we dismantle or stultify the sense of the whole, yet ultimately it is the whole that is our raison d’etre. As I’ve already suggested, the 1200s handle these conflicting demands with a self-assurance and deft poise that both provides authoritative stability and allows the music to breathe, the best of both worlds. It’s a sensibility that extends across the range, all the way from the massive flagship monos to the (relatively) baby KA S 180 – and the 650s are no exception. It’s this musical and spatial/temporal balance, very much a balance of virtues, that places the Karan amps at the forefront of solidstate amplifier performance. That and their relative affordability, for in the world of high-end audio, even the £25K asking price of the 1200s looks modest compared to the competition, while the mere £15K ticket attached to a pair of 650s starts to seem almost like a bargain (at least until reality bites).