After borrowing Musical Fidelity's humungous kilowatt kW amplifier to see how Apogee's Scintillas would fare with a modern powerhouse, I thought no more of it once it was returned. Astounding amp, sobering price, obscene use of floor real estate: it joined a list of milestones in my life, like meeting Philippe Dufour. So I filed it in the back of my mind along with other wondrous impracticals that I would never own, like, say, Lamborghini's Murcielago.

But dream-makers aren't fools. Just as Lamborghini introduced the Gallardo as a sane alternative to the aforementioned supercar, so did Musical Fidelity release the half-power kW500. And now new kW750 Dual Mono Power Amplifier not only narrows the gap, it more than makes up for the fact that the original kW sold out in record time. According to Antony Michaelson, the kW750 is a limited edition, so panic buying isn't part of the experience. Phew, I hear you sigh.

Why the relief? Because, as brilliant as the kW500 may be, there are those who crave more. So why not buy a kW in the first place? For most, I would imagine that, rarity and cost aside, its multitude of huge chassis made it a complete no-no, full stop. The kW750, on the other hand, is almost conventional, with only its extreme depth and weight reminding you that it's nowhere near as conventional as it may first appear.

You see, the power amp itself measures a considerable 19x6.6x15.75in (WHD), and it's bordered by those vicious, ankle-slashing heat-sinks that MF insists on using although there are dozens of be-finned amps on the market with the corners rounded. When you realise that this bastard weighs 75lb, it's bulky and the handles are a mere styling conceit, you'll see why I'm making a big deal out of this. If you can't place out of your path, be prepared for drawn blood. Yes, they're sharp.

Because it can be sited elsewhere, you don't have to worry too much about the kW750's outboard power supply, which needs only a space of 14.4x6.6x11in (WHD), but you might want to place it next to the main unit for appearance's sake. Then there's the matching kW Hybrid Line Preamplifier filling a space of 19x6.6x17.7in (WHD), including feet, knob and terminals. Not unmanageable, like the originals, but still deserving of deliberation before you let the seduction take hold. And seduce you, they will.

kW HYBRID LINE PREAMPLIFIER
MF states that 'the new kW super performance preamp is a direct descendent of the original ultra-limited edition kW preamp of 2003.' As such, it promises very low distortion, 'super wide overload margin', and extremely high current capacity. It should also prove impossible to clip, thanks to the huge overload margin. A very low feedback design, it has an extremely high input impedance of above 500k Ohms, with low capacitance. According to Antony, 'Whatever is plugged into it has an extremely easy load to drive and as a result produces its best performance. The higher the input resistance (and lower capacitance) that an input has, the easier it is for a signal source to drive and vice versa.'

Line-level-only - there's also a matching phono amp - the kW boasts a mu-vista sub-miniature valve in its driver stage. This is far more important that at first may seem, especially if you, as I do, attribute more of a system's sonic character to a pre-amp than to a power amp, since it's closer to the source and has more influence on the sound, amplifying as it does far less robust signals than the power amp. Conversely, a power amp has to drive speakers, all of which are imperfect loads, so you can argue it both ways. However, I experimented with four or five combinations of kWs and other preamps and power amps, and learned that the kW750 is so neutral above the bottom couple of octaves that it behave like a chameleon and ape the mid and treble nature of the preamp - where the real character emerges. As you might guess, this preamp sounds very valve-like in its warmth and 'bloom'.

Michaelson is particularly proud of its output stage. 'There is not one preamp in the world which comes anywhere near what the kW can achieve.' Its maximum output is 62V, 'so it is impossible that the kW preamp can be overdriven.' Moreover, the kW preamp has output current capacity of about 5A peak, and this is where Antony's excitement becomes so great he can hardly contain himself. 'It will produce roughly 20W RMS into 8 Ohms!' Remember, we're talking about a

-amp. Which could, I suppose, actually drive an efficient loudspeaker. AM also informed me that it is capable of an 'approximately 100W peak for one second.' 


Bearing the latest MF look, with a single huge rotary volume control and feet that light up (how long before  grows tiresome?), it is otherwise so clean and minimalist as to ooze seriousness. Accompanied by a comprehensive remote control, the kW preamp's fascia sports eight buttons with an LED to indicate its status - that's it. They summon, from left to right, power/on off, with a pair of LEDs to indicate power on and mute, tape monitor, CD, SACD, tuner, aux, HT direct (for home cinema throughput) and tape via another line input. 

Connections are equally straightforward: a pair of widely-spaced, single-ended main outputs, seven pairs of RCAs for the source components, the HT direct and output for tape record and an IEC three-pin mains input, and that's your lot. The unit is quiet, seems utterly immune to the proximity of other components, and behaves impeccably. While £2,999 is a lot of money, for once it represents almost unbelievable value. How so? The kW pre-amplifier has presence, and not just sonic.

kW750 DUAL MONO POWER AMP

With only 75 lucky power freaks in possession of this amp's 1000W parent, the kW750 will please all manner of audiophile who missed out due to either timing, finances or space concerns. This amplifier, which my colleague Paul Miller described as so powerful it could drive wet string, aspires to the greatness of the kW line's sire by offering massive reserves of power and current, conservatively rated at 750W/channel. Its dynamic range encompasses peaks of 105-110 dB. In keeping with Michaelson's belief that 'an 85dB or 86dB efficiency loudspeaker really needs in excess of 500W,' the '750 should never exhibit any clipping.

So let's get that one out of the way: whether using the hungry Sonus Faber Guarneris, or the mildly difficult Wilson WATT Puppy System 7, I could get nowhere near to a point where the kW750 seemed like it was about to turn nasty. If you've experienced WATT Puppy 7s in full-on anger mode, you know that they can take bags of power. The kW750 just said, 'Bring it on.' I stopped turning the knob when my ears started ringing. Suffice it to say, power should never prove to be an issue with this amplifier. Don't believe me? This amp is said to produce 200 amp peaks. And it most likely does. For once, the outrageous specs are not the fevered imaginings of a PR putz.

Over to Antony, who does on occasion, show a proclivity for PR putz-ness, e.g statements like, 'My amps are the only interesting products in the known universe': 'The distortion is typically less than 0.005% right up to 40kHz. The amazing technical performance is achieved with low feedback, but the real innovations are in the internal layout. Rather than using a few big, fat, lazy capacitors (and, admittedly, they look impressive), we have used banks of small, fast, efficient capacitors, very near to the output transistors. The signal path between the output transistor and its related capacitor is very short. Low resistance, low inductance, low capacitance and they're fast, really, really fast.

'This interesting circuit innovation yields huge improvements in the top end performance, without requiring any increases of other changes to the feedback configuration. When this is coupled to the exemplary layout, the result is the kW750's extraordinary performance. Typically, at 240V, the kW750 delivers 800W/ch into 8 ohms and about 1225W into 4 ohms. It is very, very powerful. Better still, the noise ratio is about 125dB down. Very, very quiet.' This is due in no small part to the power supply transformers being housed in a separate chassis to rid the unit of their hysteresis effect.

All you find on the front is an on/off button and two pairs of LEDs to indicate power on or protection activated. The back contains single-ended inputs for main in and loop output, and nice multi-way binding posts - two pairs per channel - for power bi-wiring. Across the bottom are three inputs for power and control from the outboard power supply. Corresponding sockets are locate don the back of the power supply, with a couple of user-replaceable fuses and a AC input.

For £5,999, this is - like the pre - a lot of amp for the money. By today's standards, that's clearly high-end dough, but far from extreme in a worlds where some  is prepared to sell a single-ended triode amplifier with less than 10W for US$350,000 per pair. By comparison, this one's a gift. As your ears will confirm.

THE SOUND

I'm not kidding: even cold, you know that you're playing with grown-ups' toys. Words like 'substantial' and 'commanding' spring to mind. But this is no exercise in laboratory-like precision, for the system has a distinct trait.

Let's deal with one thing straight away. I suspect that the majority of kW preamps and kW750s will be sold together, so my remarks are mainly about the two used jointly. Although I spent a lot of time doing 'mix'n'match' with McIntosh, Marantz, Musical Fidelity (Nu-Vista), Radford and Graaf pre-amps and power amps, I was not tempted even once to assume roles for them beyond the interallied. Like all good pre/power combos from the same brand, designed for each other, they work best that way.

If, on the other hand, you want one but not the other, I will allow that the pre-amp is the more valve-like and refined, the power amp the more robust and imposing. Using the compensatory approach to compromise, you would therefore use them in the most complementary way, e.g. the kW pre-amp worked better with the McIntosh MC2102 power amp than it did with the vintage Radford. (Note, too, that MF does not support balanced operation, which may play a part if you're partial to it.)

Those concerns aside, I used the combination mainly with the Wilson speakers, and with sources including the Quad 99 CDP and Musical Fidelity X-Ray V3 CD players, the Marantz SA-11 SACD player and an analogue front-end of SME 30 turntable, Series V arm, Transfiguration Temper V arm, through the Audio Research PH5 phono amp. All wiring was Transparent Reference.

There is no escaping the family trait. And I'm convinced that even with a Beretta pressing against his temple, Michaelson would deny it, but this pairing goes out of its way to produce rich, fat, luscious, romantic bass. I can imagine some regarding it as bottom-heavy, a bit too  down below: even with some thin recordings, such as Sixties Motown hits and certain US folkie releases, it proffers bass in luxuriant abundance.

I hasten to add that this is not undamped, overpowering bass, certainly not the aggressive sort found with modern dance recordings, nor the flaccid bass people think is associated with valves. (Well, OK, it is part and parcel of the 300B experience.) Rather, it's like a tilt toward the lower registers - never unpleasant, but noticeable enough to challenge its absolute accuracy.

In MF parlance, it means a foundation to the music and a subjective impression of greater mass, of weight. And you can't argue with that, especially in a world moving toward truncated reproduction thanks to digitalia, 'earbud' headphones, speaker downsizing, et al. The MFs, even with PMC's tiny DB1+ and 15ohm LS3/5As, always suggest listening to much larger, grander speakers. But once you get past this low-end enhancement - and only you know how much or how little bass strikes you as authentic - the kWs are almost too easy to assess.

Why 'easy'? Because they seem to do everything else just right. With available wattage, headroom, dynamic range, speed, detail, neutrality (above the bass, that is) and signal-to-noise not even raising their heads as issues worth discussing, thanks to the abundance of power and quiet running, what's left are two areas to discuss: scale and soundstaging. And this set-up opts for the panoramic.

Fortunately, it doesn't achieve this in the way that some idiot at the local TV emporium stretches a 4:3 image to widescreen on a 16:9 set. [Note: Any store that doesn't show images at the correct aspect ratio when they're trying to sell you a display doesn't deserve your custom.] Rather MF calls up a vast amphitheatre in which your preferred music will play. It resolves all three dimensions with aplomb, working miracles with the  soundtrack and other recordings where scale matters. And yet, on intimate works, the proportions aren't even slightly exaggerated, no doubt thanks to Michaelson's penchant for intimate classical works.

It's quite dazzling, and if I were trying to sell you a set, I'd demonstrate it first with the 1812 overture (naturally, I'd leave the room for that) followed by some solo acoustic guitar, or maybe  - you really  hear the Persuasions through this. Invariably, you'd surmise after a couple of tracks that this combination can deal with anything you might throw at it. Even the 12in single version of 'Superman' on the MoFi Kinks SACD, with its overabundance of bass, somehow stayed palatable. I'm at a loss to figure out how the kWs can accentuate the bass, yet at the same time not overwhelm you.


Bottom line? If you're ample of pocket, and have either a large-ish room or hungry speakers, a predilection for the bottom octaves, a loathing of midband coloration and the psychological need for a system that never exhibits a trace of instability, then this would by £9000 well-spent. But mark my words: audition this for more than a half-hour and you'll find it very hard to go back to low-power alternatives. Even if they cost $350,000.