With his new company’s first product, the Momentum Monoblock Power Amplifier, Dan D’Agostino hopes to re-write the rules of solid-state amplifier design.
Most notable is a concern for green issues, by addressing the amp’s power consumption when not in use. It’s a claimed 1W – not bad for a 300W amp that thinks it’s a kilowatt. Running in Class AB, and merely warm to the touch after a long session reflects a cooling system which provides much of the Momentum’s visual presence: solidcopper bars (venturis) that form the amplifier’s flanks. These embrace a chassis machined from a solid aluminium billet.
With the lid off, you see a circuit using 24 high-speed output transistors (capable, says Dan, ‘of a blistering 69MHz’). Circuit boards have through-hole construction, for better heat resistance and potentially longer life, also allowing the use of higher-quality capacitors. All resistors are 1% metal-film types, and there are no capacitors in the signal path. The Momentum amplifier is DC-coupled from input to output and is a balancedoperation- only design.
HELD ON THE SPOT
First impressions are, as William Hazlitt stated, ‘often the truest’. We knew that the initial exposure to the Momentum monoblocks would be as telling as with any item reviewed in the past. Indeed, the first track on Keb’ Mo’s Peace (Back By Popular Demand) curled around our ankles, holding us in place. We just had to stay, the planned protracted warm-up be damned.
With Keb’ Mo’s rich voice unleashed, in front of ripe lower registers, twanging bottleneck guitar work and deliciously chiming piano, we noticed other curious events. The meters seemed not to move, the preamp was only reading around 10 on its display yet the sounds that filled the room were at levels one would call realistic. Even at the highest sensitivity settings no flicker of the Breguet hand with its moon-shaped tip was seen.
Levels approaching the legally actionable, no clipping within earrange, Sophia speakers unflapped, the sound exhibited no discernible flaws. Emmylou Harris’s Hard Bargain is peppered with unusual percussion sounds, like the djembe, her crystalline voice hovering over rich terrain. With acoustic guitars and massed vocals behind her, shimmering sounds of indefinable sources, it was as if Deadwood had come back for a fourth series. The Momentum pair held up a tapestry, but one so finely woven that no coarse texture could be sensed to pixilate the whole.
On to Nick Lowe’s recently remastered Labour Of Lust and the earlier Jesus Of Cool. Lowe’s facility is for creating deceptively simple, irresistibly catchy songs with the kind of intricacies that seem to work unobtrusively in the background. You might look upon masterpieces like ‘Cruel To be Kind’ and ‘I Love The Sound Of Breaking Glass’ as throwaway singles, but that’s like calling a Ladurée macaroon a ‘cookie’. Layer upon layer was revealed through the Momentum, yet without any sensation that the Brothers Roux were poised over onions, peeling back near transparent layers.
The Momentum has bull-dozed its way into our All-Time Top 5 power amp list, alongside the Dynaco Stereo 70, McIntosh MC275, Radford MA15 and Marantz Project T-1. The lone solid-stater amidst valves, it may, perhaps, even be the best amp on the planet.
Originally published in the Yearbook 2011
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