Pre/Power Amplifiers

It started with the magnificent Tom Petty CD collection, 'Wildflowers' & All The Rest [Warner 093624899112]. Rich with guitars of various textures and Petty's distinct, slightly nasal voice, the first impression was of a deceptively analogue-like warmth which – I swear – made me think of open-reel tape rather than vinyl. The title track, despite familiarity to any Petty devotee, possessed a freshness which I had to attribute to the amplifiers' greatest strength: openness.

It's worth recalling that, since Day 1, all Momentum amplifiers have delivered bottom octave solidity and extension rivalled by the precious few. Allied to this foundation has always been a retrieval of detail which would impress Sherlock Holmes, while the transient attack across the frequency spectrum has never been less than fast, smooth and convincing. Decay has always been correctly progressive while the three-dimensionality of the soundstage was always close to the best of the triode glitterati. What the Momentum amplifiers needed was a touch more warmth – not that they were ever too icy or hygienic.

The Right Stuff
What the MxV upgrade brings to the party is a removal of any last traces of the artifice often attributed to either solid-state amplification or digital sources. It was clear with the Petty CD and with The Amboy Dukes' Journey To The Center Of The Mind [Repertoire REP 4176WZ], also on CD, that the openness, speed, clarity and other strengths of the M400MxV were having the opposite of the anticipated effect: instead of forcing the listener to hear more of what was wrong with digital playback, it seemed to be showcasing what was right. Ted Nugent's fiery guitar work on the title track of the Dukes' album had all the grit, fuzz and wail I recalled of the vinyl.

But three revelations, all on tapes, ensured that the MxV upgrades were game-changers, such that I cannot wait to hear what they'll do to the Momentum Stereo amplifier I've been using for so long. First were the duets on Vronsky and Babin's 176 Keys – Music For Two Pianos [RCA FTC-2034 open reel tape]. As ignorant as I am of classical music, a real-life piano sat 1.2m away from my left elbow as I typed. The scale and presence these recordings manifested via the D'Agostino M400MxVs was nothing short of the truly realistic.

Next came classical from the other end of the dimensional strata, the orchestral majesty of Handel's Royal Fireworks Music [Vanguard VTC-1621] with Edmund Appia conducting the Vienna State Opera Orchestra. I have no doubt that my susceptibility to its charms was enhanced by my listening sessions taking place during the weekend of Queen Elizabeth's 70th Jubilee celebrations, but the sheer mass of the recording filled the room in width, breadth, and yes, height. Arguably, the most stellar element was the massed brass, heard with such clarity and incision that my possession of a UK passport suddenly seemed all the more life-enhancing.

Command And Conquer
Up to this point, I hadn't really cranked up the sound to see if I could rattle the Wilson Sasha DAWs [HFN Mar '19], which responded to the M400MxVs with such ease that my respect for them increased, even though it had already reached a state of near-worship. What I learned via the M400MxVs was that the Sasha DAWs were even more capable, more commanding than I had thought when fed a full orchestra. Imagine taking delivery of a hypercar and sticking to the speed limit, followed by a session on a track to really stretch it. This amplifier was proving too addictive.

Then came the third epiphany, an experience so revelatory that one visitor – from a rival speaker brand – was driven to say it was the best sound he had ever heard in my listening room, and he's a frequent caller. It was, of course, the recording which helped, and it just might be the finest I have ever heard, beyond even the soundtrack to the 1967 Casino Royale or any of the usual audiophile milestones.

A New Level
Recorded in 1956, Josh White Comes A-Visitin' [Livingston Master Tape Treasury T-1085] captured the folk-blues legend with a small group in one of those early stereo situations where multi-tracking and too many microphones were yet to infect the industry. The sound wasn't merely captivating or convincing. It was mesmerising, the experience all the more noteworthy because my fellow listener was an ex-BBC engineer with a golden ear and four decades' worth of pedigree.

We both agreed: a new level had been reached in realism, authenticity and sheer transparency. Truly dumbstruck at the recreation of the studio space, the harmonic overtones on the acoustic instruments, and the reproduction of White's voice… I am humbled.

Hi-Fi News Verdict
Loath as I am to call this 'the best' (having heard the Relentless), these latest upgrades reassert the Momentum's role as a top contender for the 'state of the art' amp. What elevates the MxV over its forebear are greater openness and transparency, vividly revealed when heard side-by-side with its predecessors. Imagine the silkiness of a 300B SET, but with bottomless bass and limitless power. It's that special.