Dan D'Agostino Master Audio Systems Momentum HD line preamplifier

I thought I knew what a preamp could do. But when the Dan D'Agostino Master Audio Systems Momentum HD preamplifier ($40,000) arrived for review, all my expectations flew out the window.

The two-piece Momentum HD preamp wasn't exactly a stranger. I'd heard it in two of the finest sounding systems I have ever encountered, at a March 2019 event at Seattle's Definitive Audio and, a month later, at Chicago's 2019 AXPONA. Both systems included Wilson Audio Specialties' Alexx loudspeakers and Subsonic subs; D'Agostino Relentless monoblock amplifiers paired with the Momentum HD preamp (and other D'Agostino products); dCS Vivaldi digital stacks; Clearaudio Master Innovation turntable and cartridges; top-level Transparent Audio cabling; and HRS racks. But without hearing the Momentum HD preamp in my own system, I had no idea what it had contributed to the outstandingly open and clear, precisely focused, naturally balanced, and superbly musical sound I gushed over. All I knew for certain: If that preamp was doing something wrong, everything else had to be doing something very right.

Hence to my reference system did the Momentum HD preamp come. Arriving just one month after I had used the one-box tubed Audio Research Reference 6 line preamplifier ($15,000) to review the Gryphon Audio Ethos CD player/DAC, I took advantage of the Ref 6's presence for easy comparison. Being an all-balanced, fully discrete, zero-feedback design, the Momentum HD preamp also benefited from the extra pair of loaner Nordost Odin 2 balanced interconnects that I had used in the Gryphon review.


With its battery of six sets of balanced inputs, two sets of balanced outputs, Bluetooth antenna—for its uniquely round Bluetooth remote handset—and more, the Momentum HD's rear panel has a quasi-military appearance that seems to prioritize uniformity over grace. That look contrasts with the front panel's distinctive audio-jewelry profile, in which a large, green-lit volume meter, surrounded by a rotating volume control, reigns supreme. Other controls include eight input and operation buttons, each center-lit by a different color (footnote 1) and prominently placed bass and treble controls—which, as you'll read below, serve on a part-time basis. The Momentum HD's regal air is enhanced by its position atop its throne—a combined stand/power supply from which the preamp proper is isolated by three spiked feet. All in all, the Momentum HD, the substantial copper-and-aluminum aesthetic of which reflects the preamp's substantial cost, is anything but a plain-Jane design.

And then there's the sound—but first, a few . . .

Whys and wherefores
"I was listening to the Relentless amps at home, and I wanted to see the dynamics," Dan D'Agostino explained during a Skype screen-to-screener in which he touched upon his company's three model ranges: Progression, Momentum, and the top-of-the-line Relentless. "I was trying to get the kind of dynamic contrast and extra layer of detail from a preamp that I get from the Relentless amplifier. The original Momentum preamp was doing an awesome job, but I decided to try putting part of the Relentless preamp (footnote 2) circuit that I was working on into the Momentum preamp. Once I heard a huge improvement, I started to try to fit all the Relentless stuff I could inside the Momentum preamp. That led to the HD version. It's a monster that swings over 40 volts at the output, and has tremendous dynamic range and extraordinary fine grain detail at both low and high levels. It's not a Relentless preamp, which is much more elaborate and will cost much more, but it has some of the same circuitry and ability to reproduce the leading edge of notes and musical passages."

Dan D'Agostino designed "almost all" of the Momentum HD preamp's audio circuitry. Everything in his current line uses entirely different circuits than what he designed and used at Krell, the company he co-founded, co-owned, and served as chief engineer.

"At Krell, I used to suffer under the burden of the commonly pronounced judgment, 'The amplifiers are fabulous, but the preamps are okay'," he confessed. "I figured that if more than one person said that, I wasn't hitting the home run with the preamps like I was with the amplifiers. When I designed this preamp, I really wanted it to be over-the-top. I had to do something completely different."

Among the HD's many changes to the original Momentum preamp design is the use of a Bluetooth remote, which is said to extend its range around the corner, so to speak. The Momentum HD's ladder volume control, which D'Agostino claims "places a single resistor between you and the sound," now has an additional 60dB more volume-control steps, with 1dB increments in the critical range between 10pm and 2pm where most people listen. Every touch of the remote's volume buttons adjusts volume by 1dB.

"There's nothing digital about the volume control save for the relays, which are governed by a digital controller," he said. "But the relays are not in the volume path; it simply selects the different resistor values."


The Momentum HD's power supply/stand has grown much larger, due in no small part to a much larger high-current transformer, much higher voltage rails, and three added stages of regulation. There's a new input board that uses military-grade FETs to give the preamp a 1M ohm input impedance, and an additional output stage that has been modified to take advantage of the very high voltage swing.

D'Agostino described one of the reasons he endowed the Momentum HD with tone controls: As he was getting more involved with analog, he discovered that many of his prized records needed "a little tweak of the tone control." Rather than place the tone controls in the middle of the gain stage, as is often done, and which in his opinion invariably affects sound quality, he added a completely separate tone-control amplifier that, when engaged, diverts the signal through a circuit that is exactly the same, sonically, as in the preamp.

"When you engage the tone controls, you're not affecting how the rest of your preamp sounds," he said. "It only affects the band you're operating in. For the treble, you're working from about 7 or 8kHz up, and on the low side, from about 50 or 60Hz down. They're not big tone controls; they're not going to shake the earth, but they are going to make slight differences."

Installation and setup
Removing the two-piece Momentum HD preamp from its secure, wheel-equipped flight case and setting it up was a snap. Given the high power output of my reference D'Agostino Progression monoblock amplifiers—1000W into 4 ohms—there was no need to raise the preamp's gain from the default setting. The only question concerned whether to use the AudioQuest Niagara 5000 power conditioner into which I usually plug all my equipment, with its two high-current outlets reserved for the Progressions.

During our chat, I read Dan an email from Niagara designer Garth Powell, who wrote that my Niagara 5000, fed by a 1m 20V AQ Dragon power cable, performs at "20 Amps RMS, with a 90 amp peak current reservoir that can sustain up to 25mS at 120 VAC input. If you get a 1000 watt class A operation power amplifier, it could be an issue. Otherwise the 5000 will make the amplifier better, given its transient power correction circuit. Many companies are justifiably concerned, because many AC filters, isolation transformers, and AC regenerating circuits raise AC impedance, create a phase lag, and therefore current compress the power amplifier. We do the opposite (if you use the high current outlets)."

D'Agostino responded, "If I were listening at your house, I would plug the amps directly into the wall and plug the preamp into the power conditioner. I don't know the Niagara 5000 so I can't speak definitively, but my experience with power conditioners is that they're not doing my amps any favors. I think you should leave everything the same in order to do the initial listening to the preamp, because that way you don't mess up your reference."

I followed Dan's counsel. First, with the monoblocks plugged into the Niagara 5000, I used the Momentum HD preamp with two excellent DACs that have their own volume controls, the dCS Rossini and EMM Labs DV2. After more or less removing those volume controls from the equation by setting them to 0dB, I allowed the Momentum HD preamp to control volume and evaluated the sonic differences. I next compared the sound of the solid-state Momentum HD preamp to that of the tubed Audio Research Ref 6. I also listened to the DACs with no preamp in the chain and later evaluated the sound with the amps plugged into the wall.

Footnote 1: Illumination can be set to only turn on momentarily during changes.

Footnote 2: Tentatively due 2nd quarter 2020.

Dan D'Agostino Master Audio Systems
5855 E Surrey Drive
Cave Creek, AZ 85331

Bogolu Haranath's picture

'Oh Lord won't you buy me a D'Agostino amp' :-) ........

Bogolu Haranath's picture

JVS ...... Lord just sent me a text message ...... Lord wants you to keep the 'Momentum' going and review the new matching Momentum M400 mono-block amps :-) .......

mmole's picture

Looking forward to the review of the Vimberg Mino loudspeakers ........ They are in the same price range as Wilson Sasha DAW :-) ........

Compare the measurements of this Pass INT-25 integrated ($7,250) with twice as expensive BorderPatrol amp ($14,500) :-) .........

May be KR could also review the new Polk Audio Legend L800 floor-standing speakers with SDA-PRO technology, $6,000/pair ........ L800 were favorably mentioned by RS in a recent dealer demo ...... L800 were also favorably reviewed by S&V magazine :-) ........

Also, JCA could review the new McIntosh MC901, tube/transistor amplifier, $17,500 :-) .......

As a side note ....... May be JA1 could review the Innuos Phoenix USB reclocker ($3,149) .......It is a device used between the server/source and the DAC :-) ........

May be you (MF) could do a follow-up review of the Revel Ultima Salon2 ($22,000/pair, Stereophile Class-A full range) ........

It is about time JA1 reviews, B&W Formation Duo Wi-Fi speakers ($5,000/pair with stands) and/or KEF LS-50 wireless Nocturnes ($2,500/pair ) :-) .......

May be HR could also review the new Polk Audio L-100 bookshelf/stand-mount speakers ($1,200/pair) .....

May be JVS could do a comparison follow-up review with the Kalista DreamPlay CD player ($43,000) :-) .........

S&V magazine reviewed Polk L-800 with SDA ....... May be Stereophile could also review them with some measurements? :-) .......

Bogolu Haranath's picture

Lord ..... That is the whole idea ....... Because I'm posting this :-), my posts are getting your attention ..... Hopefully, they could get the attention of the reviewers as well ...... Thanks for your reply :-) .......

mmole's picture

...keep at it.

JHL's picture

...Bogolu is in the market for all that stuff.

Jack L's picture

......with twice as expensive BorderPatrol amp ($14,500)" quoted mmole.

Measurement, excellent or lousy, does not reflect how excellent or lousy it will sound.

So how come a tube amp with measured 5% THD sounded so much better than a solid state amp measured 0.00001% THD???

Our ears perceive music totally a different way than what the measured spec. shows us.

So let yr ears have the final say.

Listening is believing

Jack L

Bogolu Haranath's picture

What speakers (or, speaker system) are you using Jack L, and how old are they? :-) .........

Bogolu Haranath's picture

May I suggest the Wharfedale Lintons ($1,500/pair with stands) reviewed by Stereophile? ....... HR liked them with Pass Labs SS amp in addition to tube amps ........ You could also add subwoofers, if you want more bass :-) ........

Jack L's picture


"With its battery of six sets of balanced inputs, two sets of balanced outputs, Bluetooth antenna—.." quoted J.V. Serinus.

First off, who needs six balanced inputs for home audio?????

For professional recording studios maybe where miles & miles of interconnecting cables running around, which need balanced figuration to eliminate noises being recorded with the music.

Bluetooth for an audio preamp?? Who needs it for HD home audio?
I can add a Bluetooth streaming adaptor for $29.99 from Best Buy !

So helpless consumers have to drop a huge bundle to a line preamp with
redundant features not useful for home use?

Give me a break, please.

Jack L

volvic's picture

Photos don't do these products justice, they really are quite beautiful and sound really nice too. I wouldn't want to scratch it.

Ortofan's picture

... far higher levels of noise and distortion, plus a less flat frequency response, compared to the Benchmark LA4, why would anyone want to own the D'Agostino unit, let alone pay a premium of ten times the price for the dubious privilege?

Would JA1 care to speculate how adding those far higher levels of noise and distortion to the outputs of either the dCS or EMM DACs - whose measured performance was already deemed to be state-of-the-art - might possibly account for the claimed improvements in subjective sound quality?

Bogolu Haranath's picture

It is like asking ..... Would you like to date Scarlett Johansson, or ........? :-) ........

michaelavorgna's picture

Because they choose to.

Correct me if I'm wrong but it's my understanding that people are free to buy what they want.

If your contention is people must buy what you think they should buy, I'm all ears for your explanation as to why that should be the case.

Ortofan's picture

... of my question. Obviously, people are free to buy whatever they want (or choose). But, that wasn't the point.

Perhaps you can make a case as to why anyone might logically choose to purchase a device that performs much worse and costs much more than a competitor's product.

Is it possible that such an individual has chosen to acquire the item as something of an objet d'art, or example of industrial design, without particular regard to the inferior performance of the electronics contained within?

If so, then Stereophile should consider adding separate ratings for aesthetics, in addition to those for sound quality. Or, do blind tests so that a product's appearance is never an influence.

ChrisS's picture

Having and spending money does not equal "logical choice"


Does anyone do blind tests.

Jason Victor Serinus's picture

Stereophile's measurements do not confirm that the Momentum HD performs poorly, let alone performs worse than lesser priced competitive products. Rather, they confirm the dictum of Stereophile's founder, J. Gordon Holt, who maintained that sound, rather than measurements, are the ultimate determinant of a component's performance and worth.

Ortofan's picture

... the sound reproduction quality of your system when an extra device is placed in circuit that essentially contaminates or corrupts the relatively cleaner signal from either of the preceding DAC units with higher levels of noise and distortion, as well as altering the otherwise flat frequency response.

Do you somehow derive greater listening satisfaction from the audio equivalent of, so to speak, drinking from a glass that is relatively dirtier?

Would you care to speculate as to why that might be?

JHL's picture

...of audio's better designers, from at least the Fifties forward, and against the cornerstone journalist Jason has quoted you, you've managed to beg the question and anonymously demand from your interlocutor a confirming reply about a component of distortion. Or about a presumption thereof.

He's used the thing; you have not. You've made a satisfied but false equivalence, stretching an assumption all the way to another man's experience.

That confirms the rest of us finding so many of these comments - to free content - predictable, contrary to a *stereophile*, and simply bad form.

Bogolu Haranath's picture

It would be interesting to see a comparison follow-up review of Momentum HD with Benchmark LA4 (or, HPA4), by JVS :-) .......

Aescalpius's picture

I freely admit that this is counter-intuitive but let me relate my experience. I recently purchased the dCS Vivaldi DAC. I'm running it through an Audio Research Ref 40 pre and then into a pair of D'Agostino M300 monos then KEF Blades. After a break-in period, I removed the pre-amp from the chain and listened again using the full-range volume control of the Vivaldi then after about a week I put the pre-amp back in the chain. I too reasoned that it should sound better with the more direct signal of DAC to power amps but what I found was the contrary. With the pre-amp back in the chain the soundstage was greater in all dimensions, there was greater dimensionality of the instruments and performers and overall a more natural presentation, perhaps at the expense of a little detail but not at the expense of any musical nuances. I can't explain it and I was, quite frankly, hoping to find that I could dispense with the care and feeding of a tube amplifier. But, such was not the case. My findings ran contrary to my "expectation bias".

Ortofan's picture

... noise and distortion, it's not improving the quality of the signal from the dCS DAC.

If the subjectively improved dimensionality and naturalness you report hearing apparently were not present in the direct output from the DAC, how would you suggest that the pre-amp is adding or recreating these effects?

I wonder if the same subjective effect would result from simply using a tube buffer, such as the Icon BA3, between your DAC and power amp?

PeterG's picture

Noise and distortion are not the relevant measures, they are important components of overall sound quality. Any piece of vinyl that's been played more than a few times has more noise and distortion than a CD, yet many of us would prefer that vinyl to the digital version.

Ortofan's picture

... second harmonic distortion than does digital disc.

Are you sure that the sound quality you prefer from analog disc is not due to those elevated levels of second harmonic distortion?

PeterG's picture

No, I am not. As I'm sure you appreciate, that would be impossible to know.

But I am certain that you would enjoy my noisy distorted McIntosh tube amp more than you would enjoy my numerically superior NAD solid state. I hope you get a chance to listen

Ortofan's picture

... the sound quality strikes me as being too vivid - the equivalent of turning the color level/intensity on a video monitor up so high that the colors become over-saturated. Some people may like that effect and may find that decreasing the setting to a more realistic level makes the picture quality appear relatively dull.
See if your TV set has a choice between "home" and "store demo" modes and compare the resultant picture quality in those two different settings.

While it's understandable that some listeners may prefer the enhanced effects that tube amps can provide, to me solid-state amps generally provide more accurate sound reproduction.
It's simply pleasant versus accurate, all over again.

PeterG's picture

Please forgive, I should have been more specific--I agree that a high end tube amp and a high end solid state amp will lead to the same fair debate of pleasant vs accurate that we've all read a hundred times.

But to my original point of noise and distortion being the wrong things to measure--my $500 solid state amp has lower noise and distortion than my $10,000 tube set up. But I am certain that any "objective" (haha) listener would choose my tubes over my solid state.

Aescalpius's picture

You make excellent points and undoubtedly the ARC pre is adding coloration and/or introducing harmonics that are more pleasing to my ears and heart. As a scientist I understand well the scientific method and cannot explain it in rational scientific terms other than what I have alluded to above. As a musician, I know what real music and real instruments sound like. With the ARC pre in the circuit, it sounds more like real music to my ear. Much ink has been spilled on this subject and I won’t rehash the arguments here. I also once worked in the retail side of high-end audio and we learned not to trust the specifications of a component and to trust our ears to determine which pieces sounded more real and more musical. I would have loved to simplify my system and to recoup some of the $$ invested in the ARC pre but to part with it would remove some of the magic. The Vivaldi sounded fantastic on its own but much better through the ARC pre, that’s all that matters to me and I don’t care to explain it. Perhaps you’re right, all one needs is a tube buffer in the circuit in order to introduce those euphoric second-order harmonics? I would love to bring home a Momentum HD pre and do a comparison between that solid-state and my tube pre; perhaps it isn’t second order harmonics at all that account for the euphony?

JHL's picture

They're certainly not excellent questions because they boil all variables down to one or two. There are scores.

This makes the premise a fallacy. Demanding others to hew to it compounds that fallacy. Repeating it three or four times compounds it again.

Unless you control for absolutely everything you're not looking at absolutely everything. A scientist would know that. The rest of your remark is reasonable and hews to what this hobby is for, which is the personal experience - even the luxury thereof, if we must - but falling into the error that because X does Y it must sound Z is a presumption, not a finding.

Aescalpius's picture

But, I think you missed my point. I was trying to echo the reviewer’s observation that he preferred the overall sound when the pre-amp was in the circuit. Music is inherently a subjective experience. As such, trying to apply objective criteria becomes problematic. It has been well established that we have not yet found a way to quantify all of the variables that make one component sound better or worse than another. If we can’t measure the variables then how can one control for them? This is inherently not a scientific exercise. Enjoy the music!

JHL's picture

You're right and I should have been more complete.

There are two aspects to the problem at hand. One is objectivism's obvious failure of reason per data and sound. However, the second is subjectivism's tacit acceptance of this defect when it too gathers that the explanation for sound defying data is the pleasant-sounding distortion.

In other words, both camps agree that distortion data describe sound per se. This is incorrect for the reasons I gave. No one data describes sound and it would be unscientific to gather that it could.

I should have been more complete; I agree with your position - it's eminently rational and it speaks to and for experience - with that one exception.

Bogolu Haranath's picture

You could try the new version of ARC Ref.6 SE pre-amp ....... You could save $20k compared to Momentum HD :-) ........

Aescalpius's picture

Yes, but I doubt it would be as good as my current 40th Anniversary Reference pre-amp. My dealer tells me that even the current Ref 10 pre doesn’t sound as good as mine. I compared mine to a Soulution 525 last year and there was no comparison. The Soulution was a touch quicker but inferior in every other way.

Bogolu Haranath's picture

Who knows? ...... Your dealer may not be running the same speakers and amp, like your excellent combo of speakers and amp ......... Ref.6 was recently updated to SE status ........ If your dealer lets you borrow the Ref.6 SE, may be it is worth trying :-) .........

Bogolu Haranath's picture

There no magic like tube magic ....... Just ask HR, KM, AD, JA1, JA2 and ML (the older ML) ...... You could add RA and SM too, to that list :-) .........

Kursun's picture

You are absolutely right!

teched58's picture

BECAUSE it costs $40,000. That's the point [it's a feature, not a bug, etc.]. The salient question is, how much does it go for at the accomodation price.

My favorite piece of Stereophile writing, which showcases how they try to normalize the insane pricing of modern high-end equipment is this one from Jim Austin's recent review of the Audio Research Reference 160S-

''And while it's hardly inexpensive at $20,000, in a historical context it looks like a relative bargain.''

Keep in mind that trade magazine writers make maybe 80k and an editor in chief around 130k. [that would be full time. Many of the reviewers here are likely contract freelancers at several k/month, if they're lucky, or given the state of the business maybe per piece [i shudder to think], so make much less.

So we have a network of publications that caters to its betters, where maybe sometimes they get a taste of that life through, oh I don't know, systems with 120k turntables. Whenever one of us commenters mentions this, we get pointed to that one nice review they did on affordable bookshelf speakers a little while back.

michaelavorgna's picture

So your belief is that one person is "better" than another based on how much money they have.

Insecurities that run that deep must overwhelm reason.

Jim Austin's picture

Dear teched58,

I'm leaving this comment up--for now; I could change my mind; we'll see--because I don't want anyone to think my moderation is self-interested. And yet: The insinuations here are mean-spirited; indeed, your post amounts to an attack (an anonymous one no less) on the character of a whole, large group: Those of us who write (and edit) about fine audio systems and the pleasure we get from music. So, not just me, but also my writers--and I do feel an obligation to stand up for them. And yet--I will not engage with you in any kind of debate.

Please know, however--and this comment extends to others in this thread--that this kind of bad-natured, ugly, personal post is not welcome in Stereophile's comments or on our forums. I feel no obligation to leave up posts like this. Really, I require only two things from commenters: relevance (it must be about audio) and respect, for the magazine, for alternative points of view, and for the other posters. Those who consistently fail to meet those minimal standards will be expelled.

Jim Austin, Editor

teched58's picture


Thanks for your response. I will say that your points are well taken. I also do have to agree with you about my post being mean spirited. It was/is, but not gratuitously so. [That is, I do believe that the stratospherically high costs of high-end equipment has in many ways sullied our hobby. Certainly, as my post demonstrates -- and I cite it as but one example; certainly I am not the first to express such sentiments -- it has resulted in a charged atmosphere.]

All that said, I thank you for not deleting my post and I pledge to you that going forward I will refrain from these kinds of posts and stick to technical stuff.

Jim Austin's picture

... and I won't, but I will respond briefly, to thank you for your courtesy and say that the issue of audio journalists and price is indeed fraught, but I think you misconstrue it.

Stereophile is not an explicitly value-oriented journal. As such, I see my role as editor as agnostic on such issues, as on most other issues (digital vs analog; tubes vs solid state). I want to give eloquent voice to many different view points. And let's face it: There is a market for expensive audio; if there wasn't, it wouldn't be produced. Are those who want to pay hundreds of thousands for a pair of loudspeakers less worthy than you and other value-oriented audiophiles?

I am not oblivious to issues of value; indeed, I've made value comparisons in some of my reviews, and companies are not always happy about it. But value is different for everyone, and I do not think it would be appropriate for me to impose my viewpoint--whatever it is--on the magazine and its readers. It would not make the magazine better.

So, yes, Stereophile covers expensive equipment, I think fairly. A relevant factor here is that, as I wrote in another comment recently, I don't believe--and I have some evidence for this, although I cannot share it--that someone who is in the market for a $50,000/pair loudspeaker is likely to buy a $5000/pair one, let alone a $500/pair one. Our goal is to help readers find the best sound, whatever they can afford to pay.

Our hobby/industry can be parsed in many ways; Stereophile serves those that fit within its scope, without judgment. I don't think that means that we are serving our "betters."

Jim Austin, Editor

michaelavorgna's picture

I just think your ultra-narrow and unnecessarily limited notion of what makes a hi-if worth buying is just that - your notion. The idea that you feel your view is the only view through which everyone must look is simply absurd.

JHL's picture

...of those ultra-narrow and unnecessarily limited notions is the implicit demand that one characteristic speak for the entire device and that that device speak for what amounts to the entire experience. "What amounts to" because the audio malcontent never professes any attachment to music or joy at its sound - it all ends on *the other guy's* bench.

In decades of the pursuit I've yet to encounter a meter-reader who actually likes audio or who does much more than play test recordings. Too pointed? Given the alternative, I doubt it.

I for one hope Jim thins such commentary. When it's not the veiled criticism behind the gainsayer's constantly requesting comparative analysis of things he has no interest in enjoying, he's making less than veiled damnations of the high end and its fans. It's a far cry from civil respect for others and it hinders appreciation of both the music and the gear.

michaelavorgna's picture

“I don’t like that person!”

“You know them?”

“No, but I’ve seen their EKG.”

Anton's picture

“Your EKG looks terrible, it worries me.”

“But, doc, I feel great! Shows what you and your measurements know!”


I don’t get the hate for measurements. Does anybody think this preamp was made in the absence of objective measurement?

Why are we so either/or, when it’s both?

A great question, better than shut up don’t ask would be to be trying reconcile where measurements meet sonics.

michaelavorgna's picture

I don't hate measurements, which can be used as a very useful guide. Same with reviews - they can be used as a very useful guide.

What I don't find of any use is people who claim measurements tell us everything we need to know about a piece of gear. Because they don't. I also would very rarely, as in hardly ever, recommend buying a piece of gear based on a review without hearing it because a review is just that.

If we take the context of our comments into account, we find that Stereophile offers reviews + measurements. Not just measurements. Which makes perfect sense to me.

Anton's picture


RH's picture

Michael, with respect...

I do believe your reply had missed the point Ortofan was making in his post. It was very clear to me he wasn't making the point people aren't free to buy whatever they want (which is obvious) or that people ought to buy only what he would buy.

He was just asking a completely reasonable question about the rational for paying a lot of money for a "high performance" piece of gear when as good or "better" performance can be found so much cheaper.

The answer may not boil down to "I'm just buying it because it looks more cool" but it is certainly a legitimate subject!

After all: Audiophile gear usually comes with a technical story (as this review did). And *almost always* the story will contain claims of how an emphasis will be put on lowering distortion, purifying the signal chain, letting "more of the music through," lowering noise floors and other distortion artifacts. How often do you see manufacturers of expensive items saying "Our product is adding distortion, but we think you will like it?' Aside from Nelson Pass these days ;-)

No cable manufacturer gives a story like "Our cable will interact with your speakers like a tone control that causes a slight exaggeration of the treble region to give the sense of more detail."
No it's always "Our cable has .0000009 pure materials to lower distortion, and let more of the pure sonic information through!"
They are ultimately claims based on a proposed level of technical performance, which "explains" what you are likely to hear. The technical performance reasons are always emphasized as the rational for the design, not just "because if it looks more expensive we can charge more!"

Ok, so we have the technical story from Dan D'Agostino part of which plays to the usual "here are some ways we have kept the signal path purer to ensure the signal is not sullied" (e.g. specific implementation of tone controls among them).

Benchmark gives their technical story for how they'll reduce distortion.

We can measure these claims and...hooboy...what if a similar Benchmark product wins out in some significant areas?

Well, now it makes sense to ask "Wait, am I REALLY getting the performance gains touted for the super expensive component?"
Maybe not. That seems pertinent.

The fallback here is to say "But we evaluate the component on how it SOUNDS subjectively!"

(And let's leave the implications of Blind Testing for cases like this to the side, as that doesn't fit Stereophile's philosophy it won't be adopted any time soon. Fine be me).

Ok. But then, contained in Ortofan's query was the subject of "what exactly does that say when you put it together with the technical results? It doesn't seem to be on the grounds of the technical achievement. Does the reviewer simply like the bit of distortion added by the more expensive amp? If so, one can contemplate whether it takes that much money and engineering effort to add a bit of distortion to a signal that someone may like. And if so, as Ortofan asked, what do the measured results suggest could be causing the impression held by the reviewer, given it doesn't appear to be based on some new breathtaking lowering of distortion or whatever. What are you GETTING for your $40,000 over what you are paying for a Benchmark or other much lower priced product that measures similarly or better?

All completely reasonable questions, it seems to me.

Of course anyone is free to buy for whatever reasons they want. But IF..(and I leave the interpretation of the measurements to others)...an audiophile is about to spend $40,000 on a super amp or pre-amp under the impression that they are getting "higher performance" in terms of a more "pure/less distorted signal" then the facts of the measurements come to bear, and can be pointed out.

In the end it won't matter to someone who is completely focused purely on subjective assessment. But this hobby contains people with a wide range of attitudes, from super subjective to ultra objective, and combinations in between.


michaelavorgna's picture

But I appreciate your considered and thoughtful response.

JHL's picture

...to miss the point, because you begin with:

"...the rational for paying a lot of money for a "high performance" piece of gear when as good or "better" performance can be found so much cheaper."

Nonsense - there is no proof this assertion is even remotely so and there is no basis to say that it is. *Performance* has meaning. So define it in absolutely reliable terms. You cannot, which is the obvious point. It's been endlessly noted that precisely *because* gear has a sound it can't be boiled down to one characteristic.

Endless nonsense is propelled by the sighted bias that because X measures Y on Z scale, a particular sound must follow. Obviously this has never, ever been the case.

RH's picture


"Endless nonsense is propelled by the sighted bias that because X measures Y on Z scale, a particular sound must follow. Obviously this has never, ever been the case."

Sure. Measurable changes have never been correlated to predicting how anything sounds.

I guess audio gear through the years has only ever come about by chance and by random dreams and musings. I think you need to explain this to all the audio companies who have invested huge amounts of money in test equipment and measuring facilities. Since you know no measurement has ever helped in predicting a sonic attribute, you could save them lots of money!

As someone who works in pro sound, I'm also enticed by your theory!
When I work I am manipulating sound all day long via changing dB levels, adjusting EQ, adding post processing and FX, etc. I was under the strange impression that the only reason these tools EXIST is that predictable sonic changes had been correlated to measurable and hence quantifiable changes, that could be exploited be engineers to produce these tools!

But...no...it's just a fools errand to think "because X measures Y on Z scale, a particular sound must follow." Somehow the type of audio gear that appears in Stereophile is magically excepted and JA should just hang up his test bench.

Cab you tell me when you'll be presenting your findings to AES or some other relevant professional society? :-)

JHL's picture

...to that in-kind or should I use it to illustrate another instance of the fallacy of the *assumption* about sound? Which would you prefer?

(Hint: Nobody said the science was irrelevant.)

All of what you offered there was refuted by the rational disconnect between your first and second paragraph. I'm afraid leaps like that leave one less motivated to rise to the bait.

You can go back and review or you can insist I defend against an attack on something I didn't say. And never believed.

RH's picture


Well, you'd written that "Endless nonsense is propelled by the sighted bias that because X measures Y on Z scale, a particular sound must follow. Obviously this has never, ever been the case."

Which, especially with "never, ever been the case" seems a bald general claim. My reply was a Reductio ad absurdum of your claim, which if it wasn't obvious, suggests you needed to be more precise and clear in what you were actually saying. It's up to you if you want to explain more carefully what you meant or not. What, specifically, where you actually talking about?

(Hint for going forward: No one, much less I, ever claimed that the sound of audio gear could be boiled down to one characteristic. But many individual sonic characteristics clearly can be measured and often predicted.)

JHL's picture

Refine your terms. *Never, ever been the case* is only the "bald general claim" you assert when you divorce it - as you appear to have done - from its context, which is that a particular sound must follow from X measuring Y by Z. However, you go on to disclaim your attack on what I didn't say with an agreeable statement on what I *had* said, which is appreciated and which was that X - one parameter among many - cannot do such magic.

And it can't. Which refutes other remarks or allusions in this same thread about how dim someone must be to pay $$$ for something whose THD is higher than something that runs $$.

We're still a long ways from fully unpacking your first few paragraphs about the technical basis or validity of audio engineering and how we might presume it goes straight to the core of sound - technology and/or its data about which you and I know quite a few things but about how in this case Jason's sound exactly came about we know very little - but we're closer.

Are you driving at the technical basis of sound or are you really driving at what you want to believe is my or the next guy's grasp thereof? Because you might agree there's an irony in not knowing what that is - and professing it - while dinging some other guy because he simply points that out. Which I had.

RH's picture

Sorry JHL, but I find your writing style confusing. I'd asked that you be more precise/specific about your claim that it's "never been the case" that a particular sound follows from measuring X by Y and Z.

I have no idea what you ACTUALLY want to claim there, as it remains utterly ambiguous and without specific examples.

Try as I might I can not untangle from what you just posted anything clarifying or specific at all to interact with.


JHL's picture

That's fine too. Leading with a fallacy may just end with not grasping how it failed.

But it did fail. Since an abstract metric can't define sound, which you grant, we're left with an incomplete understanding. That is, we shouldn't leap to conclusions about the tech even while we can engineer it, and must. One domain is not the other.

I reckon the high end's great designers accept that as a matter of course. I've seen them say so countless times.

davip's picture

...I always thought that would be a splendid name for a drink.

In that Spirit, didn't you concur on another thread (https://www.stereophile.com/comment/591749) where I proposed that those most unmeasured of audiophile devices -- turntables -- should be (by accelerometer), that the inferred qualitative superiority of suspended-subchassis TTs that we both describe is likely measurable, vis-à-vis isolation-from-motor-noise...?

Regarding the topic in-question, you couldn't give me this D'Agostino preamp for free (unless it was to re-sell). Who on-Earth wants an amp that looks like part of the Bellerophon control-panel (doubtless prompting a 'choice' response from the late editor of Audiostream)?

JHL's picture

...with armchair technical analysis are that assumptions are leapt to about the purported* sound of a single feature, and then that that single feature obscures all the others.

Audio doesn't support armchair analysis, and even real speaker amplitude or turntable rumble or amplifier distortion are virtually without meaningful context as true, audible phenomena, while so-called objectivists demand that folks who know that are science-deniers.

The inferred qualitative superiority of suspended-subchassis tables is likely measurable. What we do with that is the problem. The other problem is leaping to conclusions about that result. What's even worse is projecting that finding, associating it with sound, and turning it into an argument.

*assumed, speculated, hoped, wished, asserted, et al.

Jason Victor Serinus's picture

Anyone who is considering a new preamp and can find a dealer who carries both Benchmark and D'Agostino is free to compare. Or you can order a Benchmark preamp with a free 30-day home trial, and then figure out how you can compare it to the D'Agostino or any of the 1001 other preamps that the great BH will likely propose. A really good dealer will let you try equipment at home, albeit just for a short time, but I don't think they're going to dispense a $40,000 preamp like candy to anyone who walks in the door. Regardless, if you can afford both, you can decide which works best for you.

Meanwhile, speculation is just that: speculation. Everyone is free to spend hours days months and years trying to figure out why I liked the D'Agostino preamp so much (not that I think I'm so important). If you think you can do that by pondering graphs, feel free. But you might just want to head to a dealer or an audio show and listen. I'll be in Chicago, Munich, and Long Beach if you want to say hello. Just set your sites low, given my height.

Bogolu Haranath's picture

I'm working on my 1002nd recommendation :-) .......

RH's picture

Anyone who is considering a new preamp and can find a dealer who carries both Benchmark and D'Agostino is free to compare.

That would be much easier for a prestigious audio review magazine, I'd think, who could disseminate such comparisons to readers :-)

"but I don't think they're going to dispense a $40,000 preamp like candy to anyone who walks in the door."

Yup. That's a problem for stating "This is all so simple..."
in terms of suggesting Stereophile readers do this for themselves.

Meanwhile, speculation is just that: speculation.

As a writer covering audio gear for the most prestigious Hi-Fi magazine, don't the questions posed about the relationship of technical claims made by a manufacturer to measuring those technical claims interest you?

Especially if the technical measurements don't seem to verify the technical claims, isn't it of interest to ponder the relationship of what you believe you hear and wonder why?

I'd think that would be very intriguing.

I'm not asking you to solve this issue. It's not easy. But the general poo-pooing tone still seems a bit strange in reply to the issues some of us have raised; that it seem somewhat beneath interest of at least some audio reviewers and audiophiles. It just seems a bit of a disconnect when it seems part of the job in audio reviewing to tell the technical story for a component, and yet seem so uninterested in the technical vetting those claims, having little care for the results. At least that's the impression often left with lots of audio reviewers. (JA seems interested in correlating measurements to sonic characteristics, which many of us appreciate! Also, I do value some aspects of subjective reviews so I certainly don't simply dismiss them).

Bogolu Haranath's picture

Oh BTW, ...... JVS does '12 hour meditation' before reviewing any audio equipment (see, below) :-) ........ Doing 'meditation' is a good thing :-) ............

Ortofan's picture

... simple.

Has JVS actually compared the USA dealer listings for Benchmark and D'Agostino to determine if there is any intersection?

If not, give it a whirl.

Also, out of curiosity, how long did JVS have the evaluation sample of this pre-amp on hand to conduct his listening tests?
Would it be possible to arrive at a conclusion about its sound quality within whatever short period of time that a dealer might provide such a unit for an in-home trial?

Jack L's picture

......never an influence." quoted Ortofan.

Since when a blind test be considered repeatably valid ????

A strong case was already established only last year end, that only white noises, (sorry not music yet) encoded with different audio digital signals at 48KHz, 96KHz & 192KHz & 16-bit depth, can be differentiated under lab conditions: in an anechoric chamber, with young people at early twenties (got sharp hearing).

So using blind tests carried out in home environment, don't expect you can get anything repeatably valid with music.

Don't hold your breath my friend.

Jack L

Bogolu Haranath's picture

Ok ..... I'll take back my Scarlett Johansson example ...... She has fantastic looks and fantastic measurements :-) ......

Bogolu Haranath's picture

I wonder whether the Momentum HD has some type of 'dynamic range expander' built into the circuit? ........ Usually those expanders lower the audibility of the quieter passages below certain given threshold ...... It could be either upward expansion or downward expansion ........ Hence, the dynamic range expansion ....... Just a thought :-) ........

supamark's picture

I own 3 preamplifiers, all but the Tandberg since new

- Denon PRA-1500: has vanishingly low distortion, lotta folks like these.
- NAD 1130: good working order, though will need recapping soon. good sound, esp. the phono input.
- Tandberg 3008a: needs refurb, but working and sounds quite good.

In order of sound quality (to me)

The Denon has by far the lowest distortion of the 3 but is also the "flattest" sounding (both in the good freq response sense and in the bad lacking dynamics/life sense). Many people think the Denon is a great pre, I don't (good, but w/ flaws). All this to say measurements don't tell the whole story. The Tandberg 3008a will go even higher in my opinion if/when Soundsmith restores it (I got it 2nd hand, they don't work on stuff that's been worked on by others).

I auditioned a used Tandberg 3002a (sounds about same as the 3008a) along w/ the Denon ca. 1991 - the Tandberg sounded significantly better but the Denon has balanced outs and the RCA jack didn't come out when I pulled a cable (that issue fixed in the 3008a but a new Tandberg cost more than 2x the Denon back then, about the same now lol) - that low quality RCA jack is primarily why I got the Denon instead (also, remote control).

Jack L's picture

.......frequency response, compared to the Benchmark LA4, why would anyone want to own the D'Agostino unit, let alone pay a premium of ten times the price for the dubious privilege?" quoted Ortofan.

Again, no matter how superior or inferior are the specs, it does not tell you how superior or inferior it will sound.

So judging on the specs alone will bring you nowhere. Use your ears to judge which will sound better.

As I already said earlier here, how come a tube amp measured 5% THD (total harmonic distortion) sounds so much better than a solid state
amp measured 0.00001% THD ?

Our ears perceive sound in a way totally relevant to its specs.

Use your ears to judge.

Jack L

Ortofan's picture

... mean that it sounds more accurate or more pleasant than a solid-state amp?

Long-time listener's picture

If the addition of tone controls to high-end pre-amps becomes a trend, I'm all for it. But I've heard tone controls that have the kind of response shown in these graphs--where the amount of boost reaches its full value only at the frequency extremes. The result is only the addition of some extra hiss in the high treble, and a dull thumping in the low bass. Much better are shelving controls, where the boost reaches full value, or nearly full value, in the MID-treble and MID-bass, because it's only there that you'll hear something that actually sounds like bass or treble--rather than empty hiss or dull subterranean thumping.

Ali's picture

As if I was reading a review of a top-notch shroom; both have the same effect on brain...Thanks for review though.

Jason Victor Serinus's picture

Please see my forthcoming back page in the April 2020 issue.

AJ's picture

Or am I misreading something....


Bogolu Haranath's picture

May be mushrooms? :-) ......

Bogolu Haranath's picture

Hope JVS is not writing about mushrooms, mushroom soup etc. :-) .......

Bogolu Haranath's picture

Some mushrooms are known to induce hallucinations :-) ......

Jason Victor Serinus's picture

You're missing something...

AJ's picture

Ok. Last Christmas party featured a system with this D'Ag HD pre, so I've "experienced" it.
Guess I'll have to read your column to see the correlation to the post you responded to.
Safe journeys.


Jason Victor Serinus's picture

Shrooms refers to magic mushrooms. Do you get it now? It's cool if you don't.

There are many ways to embark on magical journeys, some of which do not entail the use of psychedelic substances, or any substance whatsoever for that matter. I'll never forget a story that the late Ram Dass told about his spiritual teacher, Neem Karoli Baba. NKB, as we'll call him for short, was aware of Ram Dass's work with psychedelics. Wanting to understand what they wee all about, he asked Ram Dass to supply him with a major hit of LSD. He took it, and sat still in meditation pose for 12 hours. When he finally came down and spoke to Ram Dass, he said, "I understand it now. But you can do the same thing with meditation."

Yes, meditation is less expensive than the Momentum HD preamp, especially in the context of a high-end system whose other components are in a similar price range. But you won't necessarily be able to time travel with Mahler or the Dakh Daughters. Thanks to Herb Reichert, I'll be writing about the latter in my next review.

AJ's picture

Yes, that's exactly how I read Ali's comment..and your subsequent one.
Hence also my quotation of "experiencing" the HD pre a month+ ago.
I *thought* I knew what Ali/you were referring to...and now I know.
Ok then, safe "trip" down. ;-)


Bogolu Haranath's picture

AJ ...... If you could buy tickets to the Super Bowl at $10k a piece and give them to Stereophile reviewers, may be some of them could show-up for the Florida Audio Show :-) ........

Bogolu Haranath's picture

Aha ...... JVS gonna be reporting from Florida Audio Show? :-) ........

Bogolu Haranath's picture

It's not what you say, but how you say it ....... Search Google :-) .......

Ali's picture

Hi Jason, in your review you mentioned that HD sounds closer to Vivaldi while it was connected to amps directly. Just a thought, if you believe Vivaldy-Progression could give us the same quality or near, as Rossini-HD-Progression and save us some money too. Thanks.

Bogolu Haranath's picture

Why stop there? ....... JVS could do a follow up review of dCS Bartok directly into Progression amps too, without Momentum HD :-) .......

Jason Victor Serinus's picture

It's been a while since I've had the dCS Vivaldi DAC in my system, but it has on its own, even without its upsampler but with the now-discontinued Scarlatti clock, a soundstage of greater height, width, and depth; larger, denser and more textured images that consequently seem closer to natural proportions; and greater as well as firmer bass. To my ears, it takes you one major step closer to what the recording engineers hoped to capture in its full glory. I am also certain, given what I've heard at shows, that if I had larger speakers with bigger drivers—since I have Wilson Alexia 2, that would mean the Alexx or beyond—the differences between Rossini and Vivaldi would be magnified.

I expect that the D'Agostino Momentum HD preamp would only further enhance what the Vivaldi already produces on its own. What I don't know for certain is if the Vivaldi has a significantly better volume control than the Rossini, which might affect the degree of improvement. That's something that dCS or your dealer can answer. I also don't know how the trio of Vivaldi DAC / clock / upsampler would sound compared to the Rossini + clock, because I've never heard that combo at home. But I do have a friend who heard my Rossini, headed to Definitive Audio to order one, and, after listening to the Vivaldi, ordered it instead. He also just had his Momentum preamp updated to HD status and is pretty ecstatic. If I can find the time to make the 90-minute r/t to his house, I'll be able to share more about this, but that could take some time. Meanwhile, I'll copy this exchange, send it to him, and see if he has something he wishes to share. More to come....

Jason Victor Serinus's picture

Steve writes: My experience with the dCS Rossini vs Vivaldi volume control was too brief and too long ago to characterize accurately now. The Vivaldi sans clock was better sounding than the Rossini plus clock, and most of the comparison at Definitive was done with the non-HD Momentum preamp to allow quick A/B.

I will say that the Vivaldi volume control is very transparent and absent the Momentum or Momentum HD preamps would be very easy to live with. BUT, the Momentum and especially the Momentum HD is tonally richer, has more body and presence, and is even more dynamic than the already excellent Vivaldi alone; even without an analog front end to accommodate I would still opt for the Momentum HD.

Hope this helps.

Jason Victor Serinus's picture

PS: I absolutely agree with your assessment regarding the gulf between Rossini and Vivaldi widening with better/bigger amplifiers and speakers. That is my supposition as well.

The HD in no way diminishes any of the essential attributes of the Vivaldi — transparency, air, nuance and texture. However, my experience is the improvement of Vivaldi plus HD over the Vivaldi alone is at least as large if not larger than the improvement of Vivaldi over Rossini plus clock.

Having once heard the HD plus Vivaldi it is impossible for me to unhear the combo and it is my strong preference to continue to use the two together.

Ali's picture

Great follow up Jason, thank you very much indeed.

Ortofan's picture

... whatever improvements he claims to be hearing when the Momentum HD is inserted in the system?

If there is a perceived difference in sound quality when using the Momentum HD, then it must be changing the audio signal in some manner. Either it's adding something to the signals that pass through it or it's subtracting something - or maybe a combination of both.

Or does "Steve" think that the Momentum HD is somehow restoring information that is missing from the output of the dCS DAC units?

Bogolu Haranath's picture

JVS is saving his money ....... He is gonna buy Vivaldi + Momentum HD + Wilson Alexx :-) ..........

Ali's picture

Why not buying them? At least these Equipments got very low noise sir!

Bogolu Haranath's picture

Both the Benchmark LA4 and Vivaldi DAC produce 'less noise' than Momentum HD ........ See, Stereophile measurements :-) .........

Bogolu Haranath's picture

Well ..... At least Momentum HD does not produce as much 'noise' as PrimaLuna EVO 400 pre-amp :-) .........

Bogolu Haranath's picture

Want to get 'dissolved' into music? ........ Look no further ..... Get a PrimaLuna EVO 400 pre-amp :-) ........

Bogolu Haranath's picture

Pass Labs XP-22 pre-amp ($9,500) reviewed by Stereophile offers slightly better measurements than Momentum HD :-) ..........

Fruff1976's picture

It's like the Trump Tower of preamps.