Performance
The m9XX’s AKM4490 DAC is up to the job. It handles every sampling and bit rate you can shake at. It handles hi-resolution files with ease, and measurably keeps up with the rigours of 24-bit audio, including DSD.
Irrespective the adapter or battery pack, the m9XX’s noise signature is stable and non-granular. It is broken neither by active peaks nor swimmy undulations. Volume-wise, however, that noise is roughly on par with the Lynx Hilo, or a bit higher than an Astell&Kern AK100. Sensitive earphones will pull low levels of background noise from the m9XX. Even when music is playing, I can hear it, but just so. Again, I listen to music at mature levels. And, as Headfi’s Hiss King, I’m a special case. Most people will either not be bothered by it, or not notice it. And, to be honest, apart from it being there (in this case there is a deprecatory term) it doesn’t put me off. Which means that the m9XX less suited to Shure’s SE846 or Ultrasone’s IQ than is Mojo.
In all other metrics, the m9XX is brilliant. Channel balance from volume settings of 0 to 99., is impeccable and initial gain is low, and perfectly suitable to accurately control the most sensitive earphones with loads of headroom. For instance, I listen to the IQ at volumes of 12 to 20; at least 24 steps exist between zero output to what I consider comfortable. The 600Ω T1 takes the scale up to between 52 and 65. The less sensitive 600Ω DT880 takes it up to a maximum of which tops out around 80. Those are my numbers. Your mileage will vary.
What won’t is the m9XX’s power. If you can’t get enough power for your headphones from the m9XX you’re either deaf, or you’ve already broken your headphones. It provides overkill voltage for the DT880/600, the T1, and the HD880 at current-stable levels. You’ll bleed long before high-performance mode runs into IMD.
Even under load, stereo crosstalk never dips below ~88. For reference, Mojo falls to -82,1 when pushing the Audio Technical ES7. In its defence, Mojo’s stock crosstalk of -115,4dB is roughly 10dB better than the m9XX’s best effort ()detected by the Lynx HILO @+6dBv). Still, the gulf between loaded and unloaded tests suggests that the m9XX (load effect of ~15%) carries its signal better than Mojo (load effect of ~28%). Impressive. The results are similar across all metrics, but again, the base unloaded scores that Mojo kicks out sometimes quite a way ahead of the m9XX.
At the same voltage levels and through my setup (through which I’ve tested gear that tops out at +120dB), m9XX’s dynamic range tops out 114,1dB. Mojo squeaks by it at 116dB. Not that you’ll hear the difference at normal listening levels.
When loaded with an Earsonics SM2, the m9XX is stabler than Mojo by a small factor, outputting roughly 42% of Mojo’s IMD and about 26% of its THD. It’s a foregone conclusion that the m9XX is stabler than the single-ended output of any high-end modern DAP.
Maxing voltages between the two reveals about 2dB of extra volume from Mojo, but at the expense of massive upticks in IMD. Reduced by two or three clicks to the m9XX’s maximum output, Mojo stabilises. The m9XX’s top volume is rock solid and more usable loaded, and marginally so unloaded.
It is important to remember that while m9XX’s amp section may be marginally stabler than Mojo’s, Mojo’s unloaded performance is better in almost every metric; sometimes (as seen in stereo crosstalk), by a large amount. If all you’re after is a perfect signal to an outboard amp, it gets tricky. Mojo measures better. But it’s way easier to hook up RCA outs to RCA inputs; and m9XX is a way better set up for concurrent use of both headphones and line outs. If you’ve got the space, and the right power adapter, the Grace is a more elegant solution.
If you’re primarily an on-the-go listener, Mojo’s strengths are impossible to overcome. It outperforms almost every high-end portable amp in almost every metric. Its output is nearly as silent as to boot (certainly it is more silent than the m9XX). Because it’s got a battery inside, there is no need to fuss with cables. Finally, it is much smaller. On the road, there’s not a moment in which I would choose the m9XX. At home, or firmly grounded for the long term at a desk, I will reach for the m9XX every time.
Sound
The m9XX is slightly smoother and darker, while Mojo is more detail-oriented. The differences are slight, but are most noticeable in the high frequencies. The Grace is detailed and kicks out a nice, 3D stage that pushes both wide and tall, with decent y-axis space. But, Mojo has more detail and space on the y-axis. It also presents a more neutral emphasis on stereo imaging, where all frequencies receive roughly the same sound pressure (unloaded). Loaded, m9XX’s greater stability equalises much of that (small) disparity.
I prefer listening the flighty Ultrasone IQ through the m9XX. Conversely, I prefer the warmer Beyerdynamic T1 through Mojo, whose more detail-oriented signature helps cool things down.
And then there are the filters.
Grace’s crossfeed filter is brilliant, flattening stereo separation to around -22dB. No, it won’t comfort up your headphones into a two-channel setup, but it is nice for a number of older recordings. Unless listening for unbroken hours at a time, I feel no need for crossfeed for modern recordings. Your mileage will vary. Better, the crossfeed is so well implemented negatively impacts almost nothing else. THD bumps up just barely, but everything else stays roughly the same. Basically, the m9XX nets the benefits of crossfeed with little to no performance penalty.
The DAC filters are basic roll offs, with associated analogue-like minimum phase effects, or digital-domain linear phase equalisation. While I’m not qualified to talk about the accuracy of either method, I’m qualified to say that I’m impressed. I’ve not got a favourite, but F2 and F4 are often on when my DT880/600 is on. Page 12 of the m9XX manual gives a good run-down of when, why, and where to use each. F2 and F4 filters begin slow roll-offs from about 10K. Both are lovely when running sometimes-harsh sounding headphones. And while it is just my subjective option, I feel that they are less suited to warmer, mid-heavy headphones such as the T1 and HD650.
Naturally, your mileage will vary. What won’t is the thought that went into each filter, that went into each DAC option, that went into the output circuit, that went into the selection of the m9XX’s DAC. Brilliant.
Meh
I wish there were space for another alphanumeric. And, m9XX’s feet are crap. Nevertheless, the m9XX is brilliant. As a desktop DAC, it is phenomenal. I think I should add this: it would be nice if the power, performance, and beautiful DAC filters sat behind a nice balanced headphone output. There’s little about which to complain.
End words
If you don’t need analogue input, and you’re primarily listen whilst sitting at a desk, the m9XX is about as good as it gets – if you’re not super overly sensitive to hiss. Measurably it is better than JDS Labs’s The Element, but also costs 200$ more. That extra may go to raise the performance bar. It certainly has gone into making the m9XX one of the most elegant desktop headphone amps around.
And if the numbers mean anything, loaded, it even beats out Mojo. Of course, Mojo hisses quite a bit less, and boasts better unloaded performance-by-numbers. The twain represent the best in their respective classes: m9XX for the desk, Mojo for the pocket or purse.
Looks-wise, the m9XX is a Leica among Nikons and Fujifilms. And like Leica, it focuses on the essential. It is a deliberate, elegant machine.
Well done.
Chris
This nice little unit. If you could give if a try since from what I have heard the power adapter of ipad is quite good.
dalethorn
I wonder how it would work with 4 rechargeable ‘D’ cells (1.2v x 4) feeding power. Would that be a no-no?
Chris
I know some people use power banks. So it’s worth trying. But so far, I know a guy actually measured the output of ipad power adapter and he said it’s top notch. I suppose it’s not an expensive experiment.
dalethorn
For power-hungry headphones, the demand for very short-term but strong dynamics should cause the USB power to come up short. Most users probably won’t hear it, but it’s likely to be audible in some cases.
ohm image
That is only if you are playing extremely loud volumes, and even then it depends on the headphones. Some don’t use that much current. The m9XX is more powerful at high Ω and low current than the Mojo, which is more powerful than a lot of desktop amps.
The Goldmund TELOS HD – that thing spat more current into any load than I’ve ever seen. But you don’t need that much. It was complete overkill. Still amazing.
dalethorn
But the M9xx can be fed more power if the user needs it, for dynamics (not more volume), yes?
ohm image
I’ve been using it with 4x LR6 AA 1,5 rechargeable Eneloop Pro cells and the results (both measurable and at the ear), are the same.
ohm image
It is a great adapter. I detect no differences using it or the included wart that can’t otherwise be chalked up to outlier measurements. But the Apple one is so much better thought-out than most, if not all similarly sized pack-in adapters. It is better, in fact, than most similar upgrade adapters.
AlexS
Really nice review, was actually really curious about what Headfonia has to say about the m9xx ! Would you recommend it for T90s ? Or are tubes still the better way to go for these bright headphones ?
ohm image
The roll off filters in the m9XX are of high quality and sacrifice nothing major. The crossfeed also reduces stereo separation by a large amount, even more so than some valve amps. I would say that it is ALL up to you. The m9XX is stabler than any valve amp I’ve tried, though the new Triple from Cypher Labs is close. But in terms of overall performance, the triple has no candle at all. The m9XX is very good.
Chris
So I picked up one in the 2nd drop. Love to see it coming sooner.
ohm image
Well I hope you enjoy it. I understand the demurring of USB audio devices. But at a desk, I’m always plugged into one. Not necessarily because it sounds better than my iMac output (that is debatable – especially if you use high-Ω headphones), but because it is more robust, easier to use, and nicer in every aesthetic.
The m9XX is brilliant.
Chris
USB is quite convenient.
s4tch
thanks for the review. did anybody have any experience with the denon da-300usb _and the m9xx? if that’s the case, would you mind sharing some impressions?
ohm image
By _and_ do you mean as a comparison? If so, the Denon would have to perform what amounts to magic to match the m9XX. Denon amps I tested in the past didn’t come close. The DA-300USB may be better, but I’d not put money on it.
Danny F
if I want a desktop DAC/amp, would you say the m9xx is worth the $200 premium over The Element and the who-knows-how-long-if-ever wait for another Massdrop offering?
ohm image
The m9XX is a better pairing device with certain USB types that have trouble with certain external controllers, my iMac 2012 for instance. For that reason, the Grace m9XX should offer better performance throughout a larger range of computers/phones.
For its price, The Element is absolutely phenomenal, but the m9XX is a more stable platform.
Danny F
Cool, I wouldn’t have considered compatibility issues so thanks for the insight. Massdrop just finished a Chord Mojo deal that I ended up joining. Maybe not quite the level of m9XX but will be nice to have one device for both portable and desktop duties.
ohm image
As always, my comments are late. Apologies. Mojo and m9XX are neck and neck, m9XX being slightly better driving a wide range of headphones/earphones under load, Mojo spitting a slightly higher quality unloaded signal. Both are fantastic, but as you see, I chose Mojo as my product of the year.
Traveller2225
So currently I have the Audio GD-nfb28 it is a balanced DAC and Class A amplifier which I pair with the HE-560’s. I wanted to ask if you felt like this is one of better and or best DAC/amplifiers under 600$? I know this has a lot to do with personal preference, but I am okay with that
ohm image
Absolutely it is one of the best for under 600$. It offers so much for so little.
Traveller2225
Man, I forgot that I could not get into my posting on this page with normal account because it keeps sending verification to my old AOL account, so I made this one to being to chat it up no headphonia and the like. I currently use the NFB 28 If I had the money I would probably upgrade to a 27 or one with the wolfson chips. Or give some other companies a chance, but I just can’t come up with that kind of cash.
bobpensik
I’ve been debating between the Grace M9XX and the Resonessence Concero HP, how would these two compare when driving the HD600?
mika
Yes!
And the HE400i, please! They sound nice with Concero HP, and I saw very positive reviews about pairing with with m9XX. Wonder if anybody tried both and can comment on it.
And same for Beyerdynamic DT 1770 (long shot probably)…
ohm image
Sorry, I’ve not used the Concero.
Reece Conrad
Nathan,
Thank you so much for the review. I am thinking about joining in this drop on Massdrop, but I’m in a little over my head when it comes to audio equipment. I’m not sure what is “smoke and mirrors” and what is truly better equipment.
I currently have a Fiio e10k dac/amp and some Sennheiser HD598’s. I was really underwhelmed with the setup, to say the least. Would my money be better spent on a new set of cans (thinking about HE400i or HE560 or Senn HD650s) or upgrading my cheap Fiio to this?
Opinion?
dalethorn
The headphone will make a much larger and more obvious difference, but not necessarily a better difference. Mainly that’s because both amps have about the same frequency response, but the headphones are very different in frequency response. Assuming the headphone you choose sounds good to you, then if it’s compatible with the Grace amp, you would appreciate the better amp.
Reece Conrad
That’s what I was thinking. I think I’ll start with a different headphone first and then upgrade the amp once I find a headphone with sound signature I prefer.
ohm image
As Dale said, headphones make a bigger difference.
Gugman
hmmm, this great review stopped me from pulling the trigger on Lake People G109A Limited Edition. What to do now ? 🙂
dalethorn
It’s Massdrop, so you’ll wait awhile to get it, and if there’s any problem, wait a long time to get it resolved. Just be sure to have a good backup amp in case.
Gugman
I meant which one to choose 😉
for backup teac ha 501 is always ready for heavy lifting
dalethorn
You mean choosing between a DAC/amp and amp only? I’d take the Grace.
Gugman
hey 🙂 so I need a little bit of help here, at this moment i have Yulong d100 serving as a dac and as an amp Teac Ha-501. so I ordered Fostex TH-X00 and now am thinking to keep my amp, or to choose from following 3, Grace m9xx, Lake People G109A Limited Edition or something from iFi line. any suggestions? thanx
dalethorn
With the TH-X00, I’d think power first, since the TH-X00 will be very resolving, and the gentle clipping these amps do will take away a lot of the sparkle from the sound. The headphone and amp specs will tell you what has the best power, but some headphones like the Beyer T1 have a nominal impedance of maybe 300 ohms, but at some frequencies it can be 1500 ohms. I don’t know about the Massdrop Fostex, but be sure to check out its impedance curve over all frequencies. The highest number is the key.
dalethorn
I don’t know really – I don’t have it, so I have to do some research to find out. The big problem with comparing 100 amps to 100 headphones, it’s 10 thousand comparisons.
Gugman
yeah, you are right !
thank you so much for all your reply and advises !
Phil Landerer
I just posted the grace m9xx for sale on ebay if anyone wants it.
dalethorn
What don’t you like about it?
Phil Landerer
Not enough juice to power the Sennheiser HD 600. I had the volume turned to the max and it’s simply not enough.
Phil Landerer
I contacted Grace to get their thoughts, and they mentioned it could be my HD 600’s so I will give it another test and see because I am quite shocked if they really can’t power the HD line. Awesome product otherwise.
ohm image
Whatever you do, don’t bust your ears.
dalethorn
Yes, that is very strange for its size, given that a USB Dragonfly would at least provide adequate volume for most home listening.
Orly
I swear, it could be your HD600. My HD600 and HD650 gets awfully loud even at only around volume 72 of the m9XX. I can only imagine how painfully loud 93-95 would be. Haha!
dalethorn
The big bump in the impedance is around 100 hz, so if the loud parts of your music don’t have a lot of energy around 100 hz, then you’re good.
Phil Landerer
I have one of the usb connectors plugged into AC power so I know I have high power mode active and most of the songs I am testing are 320 kb quality. I am currently listening at levels of 93-95 to feel like it’s loud enough for me. Some songs I feel like I could go louder on. It depends how sensitive my ears are that day. This is me testing on power hungry HD 600’s. I plugged in a pair of Ultimate Ears UE900 IEM’s and a level of 70 was around the right level.
dalethorn
The HD600 impedance is nominally 300, but rises to ~540 around 100 hz. So by the M9xx manual, you’re getting slightly over 40 mw total, split between 2 channels. That’s OK for some music, but not enough for others.
Coll. IEm
I’m selling my mojo ,kept hugo ,do you think m9xx can replace hugo ?
dalethorn
Ignoring the sound for now, what do you think of the feature differences?
Coll. IEm
all the same ,not huge dif. only size of mojo is better for a portable .but hugo need something like Wyred4Sound Remedy to clean it sound. I prefer hugo for it’s wider soundstge and clearer treble .
mojo was very good but for me not a game changer ,chord need to step up their games and let it be a dap with hugo sound that will be huge .
dalethorn
I expect more people will go for the Hugo over the Mojo for sound quality, but that also depends on the headphone and the power output. Myself, I’d get the M9xx.
Coll. IEm
I heard chord will release another dac soon , maybe a dap not sure .
Simon
I know you compared this to Mojo due to its similar price, but I think size and portability/walkability make them fairly different devices. This device is more akin to Hugo in everything but the price.
I think this looks pretty good for the price but if I was buying a desktop DAC/amp for home I’d spend a bit more to get something with a mains power supply, or even better a separate DAC and amp, rather than potentially limiting driving authority over USB. However, I think this looks pretty good to pair with a laptop in a transportable setup if that’s your main usage scenario.
I don’t find the Mojo confusing at all. It’s easy once you get used to it. Maybe not if you’re colour-blind however. What I found confusing however was your explanation of the volume steps. I can’t understand how the 200 steps works with a two-digit alphanumeric display.
VeronikaMeaney2
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