Disclaimer: Grace and Mass Drop supplied the m9xx for the purposes of this review. I didn’t even pay import duties. The m9xx goes for 499$ USD. You can find out all about it here: Grace Design x Massdrop m9XX DAC/amp.
Form
The Grace Design m9xx is a simple, elegant device. From setting volume to cycling through source and various DAC settings, its top knob does everything. And, aside from its cheap rubber pimple feet, it is a solid and well made device. Its top plate is 5mm thick. Folding into and under it is its base, on which lie m9XX’s guts. All port niches are hollowed out of the thick one. The RCAs don’t budge at all. The optical port is perfectly flush; and the USB and mains ports sit in deep, firmly anchored wells. Four bolts, one in each corner, hold it all together.
It is a handsome, understated design, some of whose stylistic cues have been inherited from Grace’s full-size m9xx series. Of those cues, my favourites are the dual headphone out ports, whose classy grey aluminium turtlenecks come directly from the m920 monitoring system.
The two-digit alpha-numeric display is head and shoulders above Chord Mojo’s confusing alien eyes. But, since it displays everything the m9XX can do, at times, it can feel cramped.
What really tickles my fancy is the m9XX’s power supply: low-power over 0,5A USB, suitable for notebooks and computers with half-spec USB ports; and high-power fed via a proper 5V 2A USB connection. No fiddling with awkward adapters. If you’ve got an Apple 5V adapter, you should be good to go. Just pack the m9XX in your suitcase and pack the usual iDevice suspects: lightning cable, mains-to-infinity cable, a USB-lightning converter and favourite short micro USB cable. Oh, and your headphones. Grace have made a brilliant use of commonly available parts.
Function
A long press of the attenuator knob draws up or shuts down the DAC menu. Certain options: low to high power mode switching, for instance, are automatic. It’s an elegant system. Plug in a dedicated power supply to the m9xx’s 5V 2A input and the m9XX switches to high power. Otherwise, it defaults to low power.
After drawing up the DAC option you want, a single click will cycle through options for that item, while a twist of the attenuator will draw up other top-level DAC options.
Cheat Sheet: full stops after an item (dd VS d.d. for instance) mean that option is engaged. My favourite functions are: crossfeed, and display dimmer. The latter dims the display after a few seconds, making the m9XX fairly comfortable for dark rooms and bedside rigs. The former makes comfortable a number of albums.
I also reckon that people will get excited by the DAC’s digital filters: sharp roll off, linear phase; slow roll off, linear phase; sharp roll off, minimum phase; and slow roll off, minimum phase. Each one is well implemented.
Because the display stops at two digits, sussing certain sampling rates is somewhat difficult. 44,48, 88, and 96 are self-explanatory. 176 becomes 17, 192 becomes 19, 354 becomes 35, and 384 becomes 38. DSD64 becomes d1 and DSD128 becomes d2. Whatever you think, this system is far easier to eyeball than Mojo’s alien gaze.
The knob bumps softly every five degrees or so around what amounts to a volume half-stop. Since the volume scale goes from 0 to 99., it means that m9XX has a 200-step volume control. But, rather than opting for a somewhat inscrutable 0-200 scale, Grace added a full stop behind each number. 0 means off. 0. means 0,5. Brilliantly humane.
Finally, I should add that if you’ve got a battery pack that outputs 5V/2A, you can get the m9XX running from any old smartphone.
Performance, sound, and meh (get it?), after the jump:
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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