OK, so I lied: here's yet another review of a Musical Fidelity product. We simply hadn't reckoned on the speed at which Antony Michaelson turns dreams into reality, but it's with more delight than distress that I report on the most hotly-anticipated (by me, that is) British power amplifier since the reissued Quad II. Yes, dear readers, the Nu-Vista 300, betrothed at conception to the Nu-Vista pre-amplifier, has arrived. This review was pre-arranged as a sequel to the Nu-Vista, which I assessed with Paul Miller in the August 1998 issue. I just didn't expect it before next September.
Of the 497 delighted Nu-Vista owners (apparently three of them think I'm full of crap), a substantial number beseeched MF to release an ideal mate for it. So Antony got to thinkin', and it didn't take him that long to conceive of a hybrid using nuvistors to drive a transistor output stage. But the nuvistor element is (literally and figuratively) only a small part of the package, the company having gone completely overboard on the power supply, the topology, the styling and the details.
What will be familiar to Nu-Vista owners is the back-up drill: Musical Fidelity bought up as many mint nuvistors as it could find and allocated them in such a way that every Nu-Vista 300, like the Nu-Vista pre-amp, has a set of replacements ear-marked for it. Despite some grumbles on the 'Net, the general consensus is that nuvistors have a pretty long working life, so it's not unreasonable to expect a Nu-Vista 300 to have potential longevity of 20-30 years with two sets - original and replacement - of nuvistors.
Although a two-box design, the '300 is not a pair of monoblocks but a dual-mono power amplifier with separate outboard power supply. The two units are housed in the lozenge-shaped aluminium extrusions with the same styling and proportions as the X-RAY, the X-A1 and numerous other X-Series items which don't fit into cylinders. The difference, though, is the size. Without some small object to show the scale, you'd be forgiven for thinking that these enjoy the same dimensions as the X-RAY, et al. Uh, not quite. Each section measures 330x700x490 (WHD) including feet and terminals. Total weight figure hasn't been supplied, but the heat-sinks alone tip the scales at 15kg, so I'm guessing that the two weigh in at 60kg; suffice to say, they'll flex your muscles.
'Including feet and terminals', is no mere conceit because the speaker terminals (two sets, for bi-wiring) are truly something special: custom-made and massive, gold-over-solid brass, and with plenty to grip for extra tightening. The feet are massive, too, gold-plated discs that look like pre-1900 pocket watches.
The mil-spec, aluminium-billet front panels look identical until you get up close, as both feature symmetrical arrays of five countersunk apertures containing LEDs to indicate power-on status and, from switch on, the sequence of switch-on-to-operate event monitoring. On the power amplifier fascia, the five lamps include separate left-and-right stand-by and protection plus 'operate', while the corresponding lights on the power supply read left-and-right 'PSU' and 'Control', the four lamps running through a sequence until all is settled. The middle aperture on the power supply is the power-on press button.
At the back'n' sides, though, it's a different story. The power supply's case is horizontally-grooved but fundamentally solid, while the power amp section's sides are made up entirely of deep, vertical slits to form the heat sinks. At the rear, the power supply contains the three outputs to the power amplifier and fuse holders, while the power amplifier's rear panel contains the aforementioned speaker terminals, the phono-style inputs to accept the signal from the pre-amp and the array of connections to accept the massive braided cables from the power supply.
Four nuvistors inhabit the '300, two per channel driving what was described precisely as 'ultra-low-noise, super-matched pairs of bi-polars,
What else could I possibly use with the '300 beside the Nu-Vista and an X-RAY? Nuthin', that's what, though I did dabble with a couple of pieces of Krell, the luscious (but now sadly-departed) Vimak CD transport/DAC, the Pioneer DV-414 DVD player and the Myryad T-10 CD player. Interconnects were Musical Fidelity, while speakers included Wilson WATT/Puppy V.1, Apogee Ribbon Monitor, Tannoy R-1, ALR-Jordan Entry 2M and Diapason Karis, using either Kimber or Harmonix speaker wire.
While 300W/channel amplifiers are expected to meet all and any challenges with aplomb, especially after the anti-low-impedance/low sensitivity back-lash of the post-single-ended triode era has made high-sensitivity the norm, the Nu-Vista 300 both hides and emphasises its power rating. F'r'instance, you never get the feeling that the amp could easily take out your speakers and scare the cat into a permanent raised-fur situation; at the same time, you never hear a trace of clipping, a shred of strain. For some time now (precisely, since he founded Kelly Transducers), Antony has been beating everyone over the head with his unshakeable belief that even sensitive speakers need bucket-loads of power for realistic dynamics, e.g. a middle-sensitivity speaker of 89dB/1W needs 200W minimum. So, perversely, I didn't find it even remotely unusual to try the '300 with small speakers of above-average sensitivity.
Read more about the Nu-Vista 300 on Page 2.