[fuzzybaffy]

One very noticeable difference between the two is the tone. Where the uber stack is all bright and exciting (a little too exciting to me at least), the m9xx is gentler. It is still exciting in the way it delivers all the details but it is less aggressive and brittle. Just very slightly smooth. The difference in presentation was another thing that struck me. The uber stack had everything more forward and in your face whereas the m9xx is more neutral though not at all laid back.

 
It's interesting how two people (you and me) can come up with the same impressions on the very same products without having talked to each other. Definitely lends credibility to the idea that amps/DACs can have differences in sound signature. 

 

[sheldaze]

Someone already has the visual size comparison between JDS Labs The Element and Grace Design m9XX. However I must add that I am completely satisfied with the way the m9XX drives the Sennheiser HD650 headphones - no issues to my ears, versus what was prior reported. I am using the USB #1 (signal) and USB #2 (power) setup.
 
When going back to The Element, a piano sounds more glassy, less clear. The subtle details of depth and volume are less focussed, more confused on The Element. I have been enjoying The Element the past week, but there is now more cohesion in the m9XX. The m9XX is a significant sonic step above what I was hearing on The Element.

 

[olek]

Another happy user here.
 
Received it today, and ran it with background music part of (work) day, getting impression that it was definitely more transparent and clear version of the sound compared to a200p (which I like a lot too, but that is just very different kind of sound, smooth, fuzzy and not very transparent - still nice, but different and does not pretend to reflect reality too much).
 
Did some critical listening this evening with HD600 and acoustic music with some amazing desert ambiance and super-detailed guitar work.
 
9xx sounds the way I always wanted my DACMini CX to be. Very similar sound, where (1Ohm mod version) DACMini amp is a bit too dry and analytical, 9xx is a touch warm, sweet and vibrant, without losing any of transparency or detail. Perfect.
 
In fact, its amp sound is not far off from Gustard H10. Still, feeding H10 from 9xx resulted in inferior sound, losing detail and ambience in the process, probably at least partially because my RCA-RCA cables are not up to snuff. 9xx saves money by not requiring expensive high-quality interconnect!
 
Apogee Grove sounds much stiffer in comparison to 9xx. Guitar notes lose their vibrancy and sound much more pale. No comparison at all.
 
My previous preferred setup of DACMini + AQ Big Sur + O2 sounds closest to 9xx, but still, sound of that chain is a bit more dry and ... a little 'stiff', for lack of better word. 9xx wins this round as well, although it is a close call.
 
Keep in mind, those are initial impressions, and they tend to be overly optimistic. Still, they are really good.
 
Also, form factor and ergonomics of 9xx is perfect. Muting functionality is great. Ability to put display to sleep will be perfect for bedtime duties, so will it's portability.
 
Works great with linux and bit-perfect mpc/mpd playback chain.
 
Very, very happy.
 
And very sorry for those that were afraid to push the button to join the drop. Amazing device, and probably best deal (and sound) I ever had so far.

 

[mohdkhamsya]

   
It's interesting how two people (you and me) can come up with the same impressions on the very same products without having talked to each other. Definitely lends credibility to the idea that amps/DACs can have differences in sound signature. 

 
 
Right. In some cases, it can be hard to discern differences. But in this case, it's definitely noticeable. I love the uber stack. But I prefer the m9xx because as someone else has pointed, it's easier to listen to. I'll probably be able to do another comparison a week in and report perceived changes.  
 
EDIT: Fidelio X2 and m9xx one of the best pairings I've ever heard, right up there with my all time favorite of dx90>Gustard H10>HE 560

 

[kawaivpc1]

   
There's definitely a difference, but I haven't yet been able to formulate it into words.  As I mentioned earlier, it could simply be the difference in DAC chips.  It's not an exact 1:1 comparison.  Even the DAC filter settings (F1/F2/F3/F4 vs. F/S/P) are different on each unit.  
 
With about three heavily interrupted hours of listening so far, I'd say the m920 is slightly more "ethereal" and mind-expanding than the m9XX.  The low end might be slightly tighter on the m920 too, although my aural memory may be warped by listening through a Little Dot MK III over the past couple of weeks.  If pressed, I'd say the m9XX is 95% of the OMG Factor of the m920 for 25% of the price (I know I'm going to regret saying this when it's quoted by someone with 100x the clue I have about high fidelity audio).  But if you didn't have them side by side, you'd never call the m9XX anything less than amazing.
 
- Dave

Cool, thanks for your opinion!
I'd love to get m9xx during second drop. Please request this one to help the rest of us who missed the first drop!
m920 is way too expensive for me.

 

[ViperGeek]

Now for something completely different: more kudos for the m9XX. 

 
I just tried connecting my LG G4 (Android 5.1) mobile phone via OTG cable directly to the m9XX unpowered (IOW, using only USB #1 for signal+power).  The G4 powered the m9XX enough to drive my HD650 (300 ohm) and ATH-M50x (38 ohm) cans acceptably well (still better with external power on USB #2).  That's just crazy!  I expected a smartphone to be able power something like a Dragonfly, but to power something as substantial as the m9XX is amazing.  Great job, Grace!
 
Android 5.x feeds 192kHz audio to the m9XX natively, or bit-perfect via USB Audio Player PRO.
 
This DAC/amp has a permanent spot in my briefcase.
 
- Dave

 

[olek]

Oh, mine, I switched from ambient acoustic music to Blind Guardian, and I am speechless.
9xx manages to render this 'classical power metal' band rich and voluminous, with real 3d-like soundstage, and given how complex and over-saturated their sound is, that is no small feat.
It also helped to separate vocalist from the massive avalanche of guitar riffs, which is typically a problem with this band.
 
Another quick test showed that 9xx can drive 800 - ooops, 600 - Ohm DT880 with some authority, although H10 seems to be a bit better at it (and BH Crack is a bit better than H10).
Not bad for semi-portable.
 
Very musical and capable dac/amp.

 

[Allanmarcus]

  Oh, mine, I switched from ambient acoustic music to Blind Guardian, and I am speechless.
9xx manages to render this 'classical power metal' band rich and voluminous, with real 3d-like soundstage, and given how complex and over-saturated their sound is, that is no small feat.
It also helped to separate vocalist from the massive avalanche of guitar riffs, which is typically a problem with this band.
 
Another quick test showed that 9xx can drive 800Ohm DT880 with some authority, although H10 seems to be a bit better at it (and BH Crack is a bit better than H10).
Not bad for semi-portable.
 
Very musical and capable dac/amp.

800 Ohm?

 

[m8o]

Android 5.x feeds 192kHz audio to the m9XX natively, or bit-perfect via USB Audio Player PRO.

Any comment on that vs. Neutron? Thanx

 

[slex]

@olek:
n fact, its amp sound is not far off from Gustard H10. Still, feeding H10 from 9xx resulted in inferior sound, losing detail and ambience in the process, probably at least partially because my RCA-RCA cables are not up to snuff. 9xx saves money by not requiring expensive high-quality interconnect!

Did you set unity gain at 90.---?

 

[nottheface]

Mine seems to be having teething issues with my computer. Or I'm just not tech savvy enough to figure this out. The moment I connected the USB it blue screened my computer. I installed the driver from the grace design site, it still had some issues but rebooted and then it worked. Or at least my computer booted

I still can't get sound to come out of it despite it looking to be the default connected device.

 

[olek]

 
800 Ohm?

 
Oh, the magic of 8's, once you start typing them, it is hard to stop.
600 Ohms, of course.
 
@slex No, I kept 9xx on 69. It ain't unity gain, but it allowed me to precisely volume match all my amps in advance and then just switch from one to another.
 
Tried 9xx for bedtime duties. Powered it by inexpensive Enb 2x18650 battery pack, with Samsung S5 as source. Plugged in Hifiman RE-600 IEMs, they are fairly low impedance, sensitive and demand high quality 'feeding' to sound their best.
 
Perfect. Eva Cassidy's live recording sounded excellent. And Karrin Allyson's 'Ballads' were absolutely mesmerizing. Voice separation (from instruments) was almost spooky. Very smooth, transparent, detailed sound.
 
Interesting amp, spanning 16 Ohm to 600 Ohm with ease. For reference, in my opinion H10 is not so great with sensitive low-impedance IEMs while being good with higher impedance/power phones. O2 is pretty good with IEMs and up to 300Ohm, but totally peters out at 600 Ohm (gray, lifeless sound, who cares about volume). 9xx seems to cover the whole gamut.
 
Overall I would describe 9xx sound as reminiscent of O2's sound, but with stiffness taken out and gentle smoothness added in. Or DACMini's sound with added warmth and musicality. Most of warmness of 9xx seems to be coming not from slightly bumped low mids, but from smooth character of the sound itself.
 
Now I am starting to wish there was a way to feed my turntable into 9xx. Sadly, there is no way.
 
I can't have enough of it

 

[sghound]

Olek, i wept reading ur observations.
 
sadly mine is still in transit.

 

[project86]

Mine seems to be having teething issues with my computer. Or I'm just not tech savvy enough to figure this out. The moment I connected the USB it blue screened my computer. I installed the driver from the grace design site, it still had some issues but rebooted and then it worked. Or at least my computer booted

I still can't get sound to come out of it despite it looking to be the default connected device.

 
That's weird. Typically (in my experience at least) Blue Screen of Death is caused by an issue with your OS. Either corrupted OS install, or a failing hard drive. 

 

[ViperGeek]

Mine seems to be having teething issues with my computer. Or I'm just not tech savvy enough to figure this out. The moment I connected the USB it blue screened my computer. I installed the driver from the grace design site, it still had some issues but rebooted and then it worked. Or at least my computer booted

I still can't get sound to come out of it despite it looking to be the default connected device.

   
That's weird. Typically (in my experience at least) Blue Screen of Death is caused by an issue with your OS. Either corrupted OS install, or a failing hard drive. 

 
USB is a strange beast.  Anything along the chain from CPU (host) to end device, including the Enhanced/eXtensible Host Controller, Root Hub, any USB hubs along the way, and device can trigger a hiccup/exception that, if each driver up the chain doesn't handle well, can send the kernel off into the weeds (aka. BSOD).
 
Assuming you've got the m9XX in U2 mode, I'd start by unplugging all XMOS devices (that'd be the m9XX), uninstalling any software with the publisher "XMOS" in the Control Panel → Programs and Features, rebooting, then installing the m9XX drivers from scratch.  Be sure to follow the prompts during installation precisely.  Don't plug in the m9XX until prompted by the installation.  Then wait until any pop-ups about finding/installing drivers is happy.  Start slow by setting the XMOS USB Audio device as the default sound device and play something in a boring app like Windows Media Player.  If you survive that, then move on to something that can talk to ASIO like JRiver or foobar.
 
Good luck!
 
- Dave