New electronics bearing the Mark Levinson badge don’t appear too often. When they do, the world of high-end audio expects them to be exemplary. In producing its first switching amplifier, the ML design team has been able to scale things down to (almost) manageable proportions. The benefits of Class D amplifiers include increased efficiency enabling greater power output while requiring less heat dissipation in smaller, lighter and more affordable packages.
It may seem laughable, then, that ML’s first foray into designing a switching amplifier should result in a massively imposing monoblock 53cm tall and almost as deep, and weighing 62kg. But considering its power output and compared to the No33 it replaces, the No53 may be seen as relatively compact.
The No53 is not a digital Class D amplifier but employs a new take on Class D switching amplifier design using a proprietary methodology dubbed Interleaved Power Technology (IPT). This is said to eliminate ‘dead bands’ and move switching noise to beyond audibility by raising the switching frequency. It uses a massive linear power supply featuring a 2.8kVA toroidal transformer with four 47,000μF reservoir capacitors, each the size of a small beer can.
The amplifier’s exquisitely finished chassis, flanked each side by substantial heatsinks, has three internal compartments to provide shielding and isolation, the power supply sited at the bottom, the No53’s four amplifiers in the middle and control circuitry at the top. The control circuitry has an independent regulated power supply.
The No53 is also a thirsty beast, gobbling up 150W at idle and only 1W less in Standby, according to our measurements. A red LED above the Standby button does blink to remind you if you have left the amp in Standby, but glows dimly in Power Save mode (where AC remains connected to the low voltage power supply, communication circuits and control circuits only). RJ45 sockets at the rear allow ML products to be connected together using Cat 5 cables, either directly or via a router in a home network.
For our review the UK distributor provided a ML No326S Reference preamp for controlling the pair of No53 monoblocks. We listened to a 24-bit/96kHz recording by David Chesky of The Coryells – jazz guitar pioneer Larry Coryell with his two sons – performing Charles Mingus’s standard ‘Goodbye Pork Pie Hat’. Without recourse to artificial reverb, this Chesky recording is 100% natural in tonality and image perspective, captured ‘live’ by a simple crossed-pair mic set-up. Through the No53s the sound was sharply etched out of a seemingly black silence. Bass was full and rich but also fast and tight, notes stopping and starting under a vicelike grip.
The voice projected from the sound image ‘in 3D’, the soundstage created between and behind the loudspeakers gloriously wide and deep with a natural perspective. Tonal balance was dry, squeakyclean. Overly dry or antiseptic? We’ve heard this track through countless systems and usually witnessed a more ‘rounded’ tonality to the guitar solo and voice. But here the bass was so clean that the overall sound presented a more clearly delineated midrange, giving extra ‘snap’ to guitar and vocal. There was still plenty of emotion.
Playing all manner of favourites showcased the explosive capabilities of the amp, yet it always remained composed and delicate as required. Is the No53 the best power amp ever to bear the Mark Levinson insignia? There’s certainly no colourful romance, but a seductive subtlety and finesse – not to mention truly breathtaking dynamics, with power to spare.
Originally published in the Yearbook 2011
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