Dan D'Agostino Master Audio Systems Momentum line preamplifier Page 2

Setup and Connections
While RCA-to-XLR adapters can be used for source components, D'Agostino cautions that the Momentum should be connected only to power amplifiers with XLR balanced cables.

I ran the my Simaudio Moon Evolution 650D player balanced, and my single-ended Ypsilon VPS-100 phono preamplifier from its "convenience" XLR output. During the review period I also auditioned a variety of balanced and single-ended phono preamplifiers, ranging in price from the balanced LKV Research 2-SB ($2500) to the Phasemation EA-1000, which also has single-ended, "convenience" XLR-outputs.

Power amplifiers were the VTL's dual-differential Siegfried Series II Reference (which I reviewed in the May 2014 issue) and the darTZeel NHB-458, which has an actively balanced input that uses a translator to convert balanced signals to single-ended. DarTZeel suggests running the amps single-ended, but says that whatever sonic degradation the additional circuitry creates is so minor as to be inaudible. DarTZeel also suggests running preamps other than its own NHB-18S with the NHB-458s set to +26dB gain rather than +32dB, so that's how I configured the amplifiers. While the darTZeel amps began to oscillate when driven by TARA Labs' Zero single-ended interconnect, the balanced version of the Zero produced no such problems and resulted in pure-black backgrounds.

Other than the software glitch that caused the level not to return to zero when sources were switched, the Momentum performed flawlessly during the review period.


The Momentum Amplifier's Sound Duplicated
In terms of sound, this is a ridiculously easy review to write, especially for someone who's already reviewed D'Agostino's Momentum monoblock (see Stereophile, February 2013). The Momentum preamp's sound duplicates the amp's—an observation that I confirmed in one of Paragon Audio's rooms at last spring's AXPONA show, where the two Momentum models drove a pair of Wilson Audio Specialties Alexia speakers to extremes of billowy transparency and delicacy. What I heard at home is what I heard under more difficult show conditions.

I wrote in my review about hearing the Momentum amps a few years before, at a Consumer Electronics Show, driving a pair of original Wilson Sashas. I wrote of their "overall seamlessness, their tube-like midband delicacy, their bottom-end authority," and "just the right blend of speed, texture, weight, and tonality." About the midrange, I said, "They produced an airy midband effervescence, and a top end that, while not exactly white light, perfectly complemented everything below.

"The overall result," I continued, "was the production of an all-enveloping 'sonic aether' in which all of the notes swam with equal ease and at just the right time. In short, I heard at home precisely what I'd heard through the Wilson Sashas at CES: pretty much nothing. Or everything."

And that's what I heard at AXPONA, as well as at home with the Momentum preamplifier driving the darTZeel amplifiers—but less so driving the big VTL Siegfried IIs, which, because they're tubed, have a more pronounced and less transparent sonic signature, though still one that many listeners might prefer.

However, now that I have more listening time under my belt, I won't call the Momentum preamp's sound "pretty much nothing." Because what I heard when I walked into that AXPONA room was a familiar sound. When we think we're hearing "nothing" or "neutrality," we're kidding ourselves. Every audio system produces a distinctive "sound" of one sort or another. The great ones produce a sound that's so coherent from top to bottom that it dissolves almost instantly beneath the music, and so does disappear. The more "distinctive" systems have a sonic signature that never submerges and remains an obvious coloration, though one some ears might appreciate.

Low-level signal processing presents greater challenges than do the higher levels found in amplifiers, but in the Momentum, Dan D'Agostino has produced a preamplifier that duplicates the Momentum amp's delicacy, transparency, three-dimensionality, and especially its liquidity and freedom from grain without softening transients—all floating above the blackest backdrops. I'm becoming a believer in balanced operation.

Nor did it take a grizzled reviewer to hear this. My wife, who doesn't spend much time in my listening room ("too crowded, makes me claustrophobic"), wandered in one evening and, without missing a beat, exclaimed, "Wow! That sound has just the right balance of liquidity and delicacy without sounding too soft."

She nailed it. That's precisely what the Momentum preamp managed. Yet despite being remarkably revealing of sonic differences among associated gear, especially cables, the Momentum preamp was not at all "analytical" or "hyper-detailed." It seemed to neither miss anything in the sound nor add anything to it.


The front-end gear was connected with both Wireworld Platinum Eclipse 7 and TARA Labs Zero Evolution. The Platinum Eclipse is, as I previously wrote, the company's best cable, but the new, finally flexible Zero Evolution takes the sound to another level of liquidity, transparency, and limitless high-frequency extension. If you're going to buy a $32,000 preamplifier, don't skimp on cables! Or at least don't skimp on the time required to try a few different brands.

Right now I'm listen to Joe Pass's Virtuoso #2, a solo album on which the guitarist plays a hollow-body electric (LP, Pablo 231-788). It lays bare all of the Momentum preamp's strong suits: an exquisitely three-dimensional image, all of the inviting warmth of Pass's Gibson ES 175, yet with delicate string transients preserved, not sounding too soft or unnaturally edgy, but oh, so liquid.

And when I switched to something more grating, like Mobile Fidelity Sound Lab's 1982 Beatles box, The Beatles: The Collection, where both highs and lows were foolishly boosted to produce a midrange trough, thus robbing whatever warmth was originally found on some of the recordings—and in, say, the White Album (The Beatles), there wasn't much to begin with—the Momentum didn't cover up or homogenize the problem.

Tone Controls?
Just in case you missed it, the Momentum has tone controls: Bass and Treble. You remember those from the old days, don't you? Their range of adjustability is ±6dB, but the instruction manual doesn't provide a plot of their active bandwidths. Nonetheless, I attempted to repair the damage MoFi had done to The Beatles. When I reduced the bass by –3dB and the treble by –4dB, up (relatively) came the midrange, restoring much of the better tonal balance found on the original release. The midrange was still a bit thin, but overall, it made the boxed set far more listenable and truer to the original.

Mostly, though, I listened without using the tone controls, so rich, lush, and perfectly aggressive and edgy—when so required by the recording—was the sound of the D'Agostino Momentum. Analogue Productions' vinyl reissues of RCA Living Stereo recordings, mastered directly from the three-track tapes by Ryan K. Smith, revealed just how remarkable was the Momentum's sound—or the lack thereof.

I've been playing Fritz Reiner and the Chicago Symphony's recordings of Prokofiev's Lieutenant Kijé and Stravinsky's Song of the Nightingale (LP, RCA Living Stereo/Analogue Productions LSC-2150) ever since I found a mint copy (11S/6S stampers) at a small Chicago record store during the 1987 summer CES. In the Prokofiev, the clarity of the distant opening trumpet, the delicacy of the triangle and celeste, the appropriate piercing quality of the finely rendered and perfectly focused piccolo, the brassy yet burnished horns, the reediness of the saxophone, and the snap of the snare, all announcing Kijé's birth, had never been so well delineated, tonally, texturally, or spatially. Never had the rich Chicago strings ever sounded so gorgeously lush and liquid.

On my original pressing, the triangle sounds fuzzy, the tambourine covered in gauze. On the reissue, the top end is further extended than on the somewhat warm yet pleasing originals, but the reissue's transients are utterly precise, delineating a level of inner detail that naturally makes distinguishable instruments previously homogenized together. Dynamics are ridiculously greater on the reissue. In comparison, the timpani are mush on the original, yet the definition of the reissue's skin textures is far superior.

In short, the reissue sounded astonishing through the Momentum, though I have no doubt that, through lesser gear, complaints might be lodged about its "brightness" and "stridency." The point is, this reissue gets it all—if your system is up to it, you'll hear it. If your system has any etch, glare, grain, or edge, that, too, will be tacked on to the greatness—but don't blame the reissue.

Since 1987 I've picked up numerous mint copies of various desirable stampers of the original RCA, but as far as I'm concerned, the Analogue Productions reissue betters every original I've heard, in every way.

The soundtrack of the original Tron movie (1982), composed by Wendy Carlos and performed by her on synthesizer over a rich bed of orchestral and choral music, was scheduled to be issued in June by Audio Fidelity. I've played the test pressings, and this music has never sounded so spacious, particularly in terms of depth, or so texturally and harmonically complete—not since I heard the original tapes in 1982 at Lion's Gate Studios, where the film was mixed. It was recorded in the Royal Albert Hall, and finally sounds it! Yes, as with the RCA reissues, it's the new mastering's doing, but the Momentum preamp didn't cover, limit, tack on, or diminish the huge sonic differences between the original LP, the 2001 CD reissue, and the new two-LP set—not in any way I could hear.

Despite consistently producing great sonic beauty, the Momentum also brutally revealed deficiencies in and additive colorations of source components.

The D'Agostino Momentum preamplifier ruthlessly revealed differences among gear, cables, and recordings, and consistently produced ear-pleasing liquidity and tonal and harmonic beauty. Ugly-sounding recordings sounded ugly. The great ones? Oh, my!

How has Dan D'Agostino done it? I can't answer the question in technical terms, and as I write this I haven't yet seen John Atkinson's measurements, but here's the recipe for what I heard: Take an ultraquiet backdrop. Then, without making the sound too soft or too etchy, add just the right balance of liquidity and delicacy, to produce natural transient attacks, a generous, almost tube-like sustain, and take-your-breath-away decays that produce the sensation of floating on a cloud. Combine that with precise, three-dimensional imaging—particularly in terms of front-to-back-of-hall image delineation—expansive soundstaging, explosive dynamics, and exceptional transparency, and you have the Momentum's "sound."

Which begs the question: Does the Momentum let this sound through, or does it create this sound? I don't know—and after living with it for many months, I could not care less. But if you ignore cables, you do so at your sonic peril. Driving the sonically similar darTZeel NHB-458 monoblocks connected with TARA Labs Zero Gold speaker cables, and with TARA Zero Evolutions interconnects from the source components, my results have been everything and more than one should expect and demand from an audio system that costs more than what one paid 15 years ago for one's very nice home in a very nice 'burb.

Dan D'Agostino Master Audio Systems
PO Box 89
Cave Creek, AZ 85327
(480) 575-3069

Allen Fant's picture

Nicely! done MF.
I have had the pleasure to seeing this gear in real time. Very much like a fine wristwatch or roaring sportscar, it is simply gorgeous.

Psychedelicious's picture

Great to know that wives only need five seconds to judge a piece of gear accurately. Mine does the same thing.