Grace Design x Massdrop m9XX DAC/Amp Review: First Impressions
Oct 23, 2015 at 5:43 PM Thread Starter Post #1 of 2,153
Written by Jude Mansilla
Ever since I laid eyes on the Grace Design m902 DAC and headphone amplifier combo ten years ago, I wanted to own something made by Grace. The Grace m902 was a stunning piece of gear to look at, at a time when headphone-driving gear was not often, There was much more to the m902 that captivated me beyond its looks, though. The m902 was released at a time when DAC/amp combo pieces weren't nearly as common as they are today, and was among the first high-res USB DACs that also had serious design focus on the headphone amplifier circuitry. In a sure sign of how serious they were about its headphone output performance, Grace Design even licensed Jan Meier's crossfeed design for the m902, and I was (and still very much am) a fan of crossfeed when it's needed.
(Above) Grace m902, which has long since been discontinued.
Somehow, I never ended up buying the m902. The years passed, the m902 was discontinued, replaced by the m903 (which had a new crossfeed circuit by Grace designed to minimize perceived bass loss). Last year, the m903 was replaced by the improved (and still current) m920. Over the years, though, several visits to recording studios equipped with Grace gear kept Grace Design on my mind.
Then, some time ago, Will Bright from Massdrop called me to ask if I was familiar with Grace Design. Not only was I familiar with Grace, I said, but proceeded to tell him all of what I just told you in the paragraphs above. He told me Massdrop was working on a collaboration with Grace to take all of the audiophile components in the nearly $2000 Grace m920, to improve them where possible, and then to release it as something more accessible, more affordable. Assuming all went as planned, they were shooting for around $500. I sent him my credit card info. (If you think I'm joking, you can ask him yourself.)
Months had passed, a plain box arrived, and inside was this:
It's called the Grace Design x Massdrop m9XX DAC/Amp. "Let me know what you think," Will said via text. "Take my money," I replied--and I hadn't even heard it yet. Well I've heard it and used it now, and I'm happy to report that Grace Design and Massdrop have crammed a lot of performance into this little beast. Go ahead and charge the card, Will.
Whereas the $1995 Grace m920 uses an ESS Sabre DAC, the Grade x Massdrop m9XX employs AKM's flagship AK4490 DAC. It is 32-bit 384kHz capable from USB (and 24-bit 96kHz capable from optical). The m9XX's also supports DSD up to DSD128 via USB.
The power supply of the m9XX is a very cool adaptive design that allows for some nice flexibility, with both low-power and high-power modes. In low-power mode, the m9XX can be powered strictly from USB buss power, outputting up to 100 mW per channel into 32Ω. If you also use the second USB power input on the m9XX, however, high-power mode is enabled and increases the m9XX's performance, including increasing maximum output at 32Ω to a robust 1020 mW per channel. (Grace x Massdrop includes a 5V, 2A power supply with the m9XX.)
Inside the m9XX, five separate power supplies are designed to deliver clean, isolated power to the digital and headphone amplification sections. Of this power supply, Grace x Massdrop said this: "The power carefully filtered with multi-tiered noise suppression for artifact-free playback from the sensitive DAC circuits and amplification unrestricted by any annoying buzz or background hiss." My first impressions suggest this is a very fair claim (which I'll comment on later).
Michael Grace also added: "As for AKM implementation in this box we worked hard on power supply filtering. USB buss noise can easily pollute clock timing and DAC reference voltages. AKM DAC is much more immune to power supply noise than Sabre. Sabre requires elaborate and expensive power supplies to work correctly. Also, we were able to get actual dac harmonic distortion lower than AKM specs with our analog filter design."
Speaking of filters, the m9XX offers user-selectable digital filter settings:
  1. F1: Sharp roll off, linear phase;
  2. F2: Slow roll off, linear phase;
  3. F3: Sharp roll off, minimum phase;
  4. F4: Slow roll off, minimum phase.
I've not evaluated the different filter settings yet, but will both listen to them and measure them later.
The m9XX's headphone section incorporates Grace Design's latest crossfeed, identical to the crossfeed circuit used in their $1995 m920 DAC/amp. Again, I am a big fan of crossfeed, when it's needed. With exaggerated stereo recordings (like a lot of stereo Beatles) containing unnatural, extreme left-right panning, crossfeed (for me) can be an absolute must.
I also want to point out that the m9XX's headphone amp's output impedance is a super-low 0.08 ohms, so you should have zero issues where that's concerned.
The Grace Design x Massdrop m9XX arrived at a time when my travel schedule was (and still is) going full-tilt. Since the m9XX weighs only 14 ounces and measures a very compact 4” x 5.25” x 1.8”, it has been accompanying me on my travels. I'm in Tokyo now for the Tokyo Headphone Festival, and I was informed that Massdrop is announcing the drop for the m9XX today, so I wanted to give a few quick impressions of the m9XX:
  1. I will confirm that the m9XX is dead quiet with most of my headphones. Plugging in my very sensitive FitEar MH334 custom IEMs--which usually dive well into the noise floor of headphone amps--reveals almost perfectly dead silence from the m9XX, which is impressive.

    (Above) FitEar MH334 Customs with Grace Design x Massdrop m9XX
  2. I did some quick preliminary measurements of the m9XX with the Audio Precision APx555 audio analyzer we have at the office, and the SNR (signal to noise ratio) of the m9XX measured an impressive 110+ dB. The m9XX's frequency response from 20Hz to 20kHz was also impressive, deviating no more than 0.08 dB in either channel across that range. (I'll share more measurements of the m9XX after a more careful measurement session with it.)

    (Above) Preliminary measurements of Grace Design x Massdrop m9XX using Audio Precision APx555 audio analyzer. Signal to noise ratio (left) and frequency response deviation (from 20Hz to 20kHz).
  3. The sound when driving my MH334 custom IEMs is superb. In addition to the very low self-noise, I love how the m9XX doesn't comes off as clinical or dry, despite its resolving nature.
  4. I find many (perhaps most) desktop amps have overly aggressive taper with the ultra-sensitive FitEars, which is most certainly not the case with the m9XX. The m9XX's  volume control allows very fine, very precise control with the FitEars.
  5. I tried the Astell & Kern AK T8iE (a lovely smooth sounding, high-end universal-fit IEM) with the m9XX, to see if the smooth-yet-detailed quality of the m9XX would come off as overly mellow with the AK T8iE, and was thrilled to find that wasn't the case at all. The AK T8iE maintained its character, but detail still jumps very nicely from them from the m9XX. (The m9XX, in terms of self-noise, is also dead silent with the AK T8iE.)

    (Above) Grace Design x Massdrop m9XX with Astell&Kern (and beyerdynamic) AK T8iE.  
  6. The m9XX has paired well with the Audeze LCD-4, driving it without any sense that I was shortchanging the new $4000 Audeze flagship. Midrange resolution and body--LCD-4 strengths, to say the least--were served beautifully by the m9XX. Power on tap seemed more than up to the task with the LCD-4 in early listening. I'll do more listening with the LCD-4 and the HiFiMAN HE-1000 (the latter of which I haven't plugged into the m9XX yet) when I settle back in at the office.
  7. I've only preliminarily used the Sennheiser HD 800 with the m9XX, and it is a very nice and surprising pairing. I only mean it's surprising to me in that I haven't found many small form factor solid state amps that I'll use with the HD 800. Add one more to the list. Will it replace my favorite tube amps with the big Sennheiser? No. But for a rather portable monitoring I'll have to spend more time with this combo.

    (Above) FitEar MH334 Custom and Sennheiser HD800 with Grace Design x Massdrop m9XX.
  8. I have also preliminarily used the new Shure KSE1500 electrostatic in-ear system fed by the Grace Design x Massdrop m9XX, and here's what I'll say, at least as far as first impressions go: If you pick up the KSE1500 and its $3000 price tag has your budget nearly tapped, yet you need a worthy source for the flagship Shure...seriously consider the m9XX.
  9. The build quality of the m9XX is wonderful. Its gorgeous chassis (co-designed by Massdrop's Will Bright) is made of aluminum and steel, and has a beautifully contoured, thick top plate that gracefully cascades over the front and rear of the m9XX. As someone who's always wanted to own Grace gear, I was also thrilled to find that they incorporated the very attractive trademark Grace bezels around both headphone jacks.
  10. The volume control, which also serves as a press-down control knob to access the m9XX's various options, has Grace's trademark feel, subtly (and silently) clicking under my fingers as I turn it--it's a lovely, premium feeling control.
After I settle back into the office, after a few more miles with the m9XX, we'll shoot a Head-Fi TV episode that includes it and says more about it, as I'm very excited about m9XX in early use. I'm thrilled to finally own my first piece of gear by Michael Grace and Grace Design! It's about time.
Check out Massdrop's drop on the m9XX by CLICKING HERE or on the photo below:
(Above) Shure KSE1500 Sound Isolating Electrostatic Earphone System with Grace Design x Massdrop m9XX.
Oct 23, 2015 at 5:52 PM Post #3 of 2,153
Review: Grace Design x Massdrop m9XX DAC/Amp
Have you ever experienced a day where you knew it went well, but did not know how much of an effect that day would have on your life? This was the case the day that I spoke with Massdrop's Will Bright about a couple of amp-type products that they were going to launch in the near future. One was a small (very small), but powerful DAC/amp called the CEntrance DACport Slim, and the other was an amp that was from the Colorado, United States-based company Grace Design.  I have conversed with Will on multiple occasions and in person, and I can comfortably say that his collaborations are exemplary and intriguing.  Usually what he likes, I like as well.  This comes back to the days (not too long ago), when all that we talked about were our Shure SE846 earphones with vigor and excitement.   Wanting to learn more about Grace Design and amplification in general, I graciously accepted the offer to share my opinion.  I have experience with most aspects of high-fidelity audio, but haven’t owned any significant DAC/amp in my life.  This was until I received a box with the words “GRACE DESIGN” ablaze on it.  Curious to find out what was inside, I opened it up.  My jaw dropped and my eyes widened.  Behold…
The Grace Design x Massdrop m9XX DAC/Amp
Clockwise starting at upper-left:  USB type A to USB type B micro cable 6', 2A power adapter,  USB type A to USB type B micro cables 10', m9XX

Front of m9XX

Front of m9XX

Volume control rotary encoder

Rear of m9XX

Underside of m9XX

Audio equipment used in the review
CEntrance DACport Slim: $99 shipped in the United States
Grace Design x Massdrop m9XX DAC/Amp: $499 shipped in the United States
HIFIMAN HE1000: $2,999
Master & Dynamic MH30: $349
Master & Dynamic MH40: $399
Sennheiser Momentum 2.0 AEi: $349.95
Puro Sound Labs IEM500: $199.99
Sennheiser Momentum In-Ear: $99.95
Shure SE846: $1,000
Sensaphonics Custom Sleeves: $150 (used with Shure SE846)
Third-party cable
Headphone Lounge FBI Reference Silver Litz Cable (MMCX) = Price varies
iPhone 6 (Space Gray, 128GB):  $849.99 or $399.99 with a 2-Year Contract
Questyle Audio QP1R Golden and Space Gray: $899 USD
Samsung S5 (Shimmery White): $552.00 with Verizon
Software Applications Used
JRiver Media Center 20: $49.98
Sound Level Analyzer: $4.99
TIDAL HiFi – Lossless: $20 per month or $10 with student discount
Adapter for 1/4 inch headphone inputs
iMBAPrice Premium High Quality Adapter STEREO GOLD Plug 1/4" (6.3mm) Male to 1/8" (3.5mm) Female - Gold Plated - Lifetime Warranty (I use a similar adapter): $5.09
If you have read my earlier Head-Fi posts (mostly in the Shure SE846 Impressions Thread), I say that the iPhone is enough for an IEM, and that I am in no need for a DAC/amp.  Being able to attend various meets and listening to a plethora of awesome sounding DAC/amps, my position started to change slightly.  I still feel that an iPhone sounds great.  However, having that extra kick, clarity and overall audio coherency that a properly implemented DAC/amp can provide is paramount.  This is especially true when you are dealing with the task of driving less efficient headphones. 
I would like to share my experience with the m9XX over the time that I have been able to own this graceful, yet powerful DAC/amp.
I feel that since there are only 500 units being dropped on Massdrop here:, I should explain why you should purchase this DAC/amp.  This is one of my favorite sounding DAC/amps regardless of form-factor and price that I have listened to.  Once you factor in the form-factor, price that is not exorbitant, as well as the exclusivity of owning a limited-run (possibly) device, you owe it to yourself to give the DAC/amp a shot – not just a listen…but a purchase.  What’s great is that you can buy the m9XX and not love it.  You can then give the m9XX to a friend, family member or audiophile/music lover as a gift, and as a result, they will adore the sound that the Grace Design DAC/amp effortlessly produces.  I call the m9XX a “Portable Desktop Solution”, or “PDS”, respectably.
More about the PDS moniker, why call it that? 
Portable – powers IEMs with the linear volume selection, meaning from “0.” (or ½/.5) to about 50 (with a sensitive IEM such as the Shure SE846) the volume rises very gradually.  The m9XX powers most all headphones with some serious power at the higher numbers.
Desktop – emits a dedicated desktop/quality (or better) sound, which is amazing for its miniscule dimensions.  Headphones get VIP treatment, and IEMs get VIP treatment as well, as both are taken care of with the utmost of affection.
Solution – this is a portable desktop solution for higher powered phones like the Samsung S5, computers, or anything that utilizes a lineout or optical out.  The solution is an immensely high-fidelity sound in the palm of your hand that you can transport, and as a result, is simply marvelous.
Let's get connected
When I first connected the m9XX, I got absolutely no volume from my HE1000.  What I did not know until I realized after a few minutes, was that even having the volume at “40” does not do much good for the average difficulty to drive HE1000.  The volume stays at a low volume up to about “50” for sensitive IEMs, which is an amazing feature the m9XX offers.  I usually keep the volume low when listening to a DAC/amp for the first time, since I have experience with volumes higher than normal when I try out the DAC/amp for the first time (for instance, listening at a meet), so having the volume very low, and turning it up was not helping at all.  As soon as I “went for it” and turned it up to the 70’s and 80’s, did I start to hear any substantial volume.  Once I was able to hear the music, the volume escalates very quickly, and with aplomb.  The m9XX is able to power difficult to drive headphones, as it has more power than my QP1R (which does well with difficult to drive headphones) and the DACport Slim (which also powers headphones well despite its diminutive size).
Keep the music playing
As mentioned in the manual, if you connect and sometimes disconnect the headphone from the m9XX while music is playing, the m9XX will show “OC”, which means “Over Current”.  The internal processor will mute the audio and momentarily shut down the audio supplies to protect the m9XX from damage and to also keep the m9XX from drawing excessive current from your computer.  When the m9XX shows “OC”, the volume will be muted for several seconds, and then will turn back on.
I experienced "OC" during these situations:
  1. Unplugging/plugging in earphones/headphones at higher volumes.
  2. Anytime the m9XX was playing at a high volume at approximately 90s and higher with headphones plugged in (never tried with earphones because anything “90” and above can damage the earphones since the volume output is exceedingly loud).
  3. Using only the USB input from a computer will cause the m9XX to “OC” while very loud music is playing at approximately 90 and higher (Low Power mode).  Adding in the external power source (via “5V, 2A" USB input – High Power mode) allowed the m9XX to reach the entire volume range (“99.”) with ease and does not “OC”.
  4. Muting the volume before plugging and unplugging in the headphones/earphones during Low and High Power modes made it so I would not experience “OC” at all.
Higher power devices should work
I tried to get my iPhone 6 connected to the m9XX via Apple CCK, USB hub and outlet power/external battery charger, to no avail (keep reading, solution below):
However, I spoke with a m9XX owner and friend @HiFiGuy528, and he was able to get his iOS devices (iPhone 6 and 6+, etc.) working with his Cute USB 2-port hub!  It can be purchased here:  I purchased one in black, and it arrived and works with the iPhone 6 without any issue.  Here's the setup:
Cute USB Mini 2-port USB 2.0 Hub Splitter

Side view

Showing 2 USB ports

Connected to Apple CCK

iPhone 6 to Apple CCK to Cute USB Mini to USB A/USB B to USB input; USB A/USB B to power outlet

iPhone 6 to Apple CCK to Cute USB Mini to USB A/USB B to USB input; USB A/USB B to external battery charger (Anker PowerCore+ 13400mAh external battery charger shown)

Close-up angle of same connection above

Connection updateWith the 0008_DFU m9XX firmware update, I was not only able to get the iPhone 6 to connect on it's own (via power source as well), without the need of a USB add-on such as the Cute USB Mini 2-port Hub, but I was able to get the m9XX (using Windows 7 Ultimate) to set as the default automatically when it's plugged in each time!  Very happy with the update:
iPhone 6 to Apple CCK to USB A/USB B to USB input; USB A/USB B to external battery charger (Anker PowerCore+ 13400mAh external battery charger shown) and IEM500

iPhone 6 to Apple CCK to USB A/USB B to USB input; USB A/USB B to external battery charger (Anker PowerCore+ 13400mAh external battery charger shown) and HE1000

I was able to get my friend and Head-Fier @Netforce's Samsung S5 working via S5, USB to USB mini cable and external battery charger:

TOSLINK optical input
I wanted to see how optical would fare with the m9XX, so I connected the QP1R to the m9XX optically, using a TOSLINK optical adapter with the optical cable for the QP1R, connected to the m9XX.
TOSLINK optical cable adapter and optical cable

TOSLINK optical adapter connected to optical cable

TOSLINK optical connected to QP1R

TOSLINK optical from QP1R connected to m9XX

“Dropped” Massdrop m9XX’s will have the updated firmware that will silence the music when a file over a 96kHz PCM digital audio signal attempts to play via optical.
The sound from the HE1000, QP1R and m9XX was sublime, and was highly resolute and utterly transparent.  I would say the presentation was such a rewarding experience that you would want to listen to just one more track.
Family game night
I brought some of my audio equipment for my family to listen to. 

The only person to listen to the m9XX that night was my younger brother. 
My brother listening to JRiver + HE1000 + m9XX

My brother is interested in video games, computers and music, but not necessarily higher-fidelity or more expensive equipment.  He was game to listen to the m9XX and share with me (and now, you) his thoughts.
Here's my brother's thoughts after listening to a few tracks from Tidal, HE1000 and m9XX:  “Very crisp and clear.  You know the “Five” gum commercial?  You are surrounded by the vibrations, and it feels like you are there.  It feels like you are surrounded by the music.” 
After listening to Logic – Like Woah via Tidal, Sennheiser Momentum 2.0 AEi and m9XX, he said it sounds like digital surround.  He says he that can hear the drums behind him. 
Next up is the MH40 same track – he says it sounds almost like the Momentum – good!
Finally he takes a listen to the MH30 – he likes the bass on these. “One thing that stood out was the bass. It really stands out. Good sound. More compact than the others.”
Great, now let’s go for a comparison.  I played a song that was melodic, popular, and just a fun listen for my brother to make comparisons – Kings Never Die from Eminem and Gwen Stefani.  He listened to both the m9XX and QP1R on the Momentum 2.0 AEi, playing the same track at around the same volume, calibrated via Sound Level Analyzer.  He preferred the Grace Design amp sound compared to the Questyle player’s sound. He said the Momentum 2.0 AEi's sound with the m9XX sounded very quiet and said with the QP1R it sounds like you know you are wearing headphones. 
Next up, the HE1000 is ready for the comparison.  He says that there isn’t as much interference or background noise with the m9XX than the QP1R has. He articulates: “You know when you are shopping for TV's and the color black that is blacker determines the better TV, same way with the sound of the music as well. When there is more silence on the quieter parts the better it sounds. With the amp I think it sounds pitch black with regards to background noise.” 
Ray Charles & Count Basie Orchestra - Oh What a Beautiful Morning is the next track that is being compared that sounded amazingly graceful (no pun intended, or maybe, who knows?) with the HE1000 and Grace Design DAC/amp.  The next song that I played was a 320kb song, Ed Sheeran's Bloodstream, and my brother thought it sounded great. He iterates: “Sounds so good for being a lossy file. Can easily mistake it for a song of a higher bitrate. Very clear.” 
Overall, my brother thinks that the DAC/amp is worth it for the price for audiophiles. 
Notable features
Low and High Power modes, which is great because you do not have to depend solely on High Power mode/outlet power, as using Low Power mode/USB and an external battery charger makes the m9XX truly portable.
The TOSLINK optical and RCA output gives you another way to enjoy your music – via power amp or powered speakers which is always welcome.
Two headphone outputs makes it so you and a friend can listen to the same song.  What I do if I know there is a “mismatch” with a headphone/earphone such as one requires more volume than the other; I will only match near efficient pairs.  For example, I can pair the easy to drive Sennheiser Momentum 2.0 AEi with the very easy to drive Shure SE846 in respectable inputs.  I can also pair a little bit more difficult to drive HE1000 with the more difficult to drive IEM500 in respectable inputs.
Crossfeed circuitry is a welcome option as it can be turned on or off. I keep the crossfeed on.
The volume control is the overall best looking and feeling rotary encoder that I have ever felt.  This is the truth.  The volume control is the truth.  The tactile feedback is immeasurably satisfying.  You turn the rotary encoder either way to turn up or down the volume.  You press it down with a satisfying “click” sound to mute the audio (and negate ever experiencing “OC”!)  Once you keep the rotary encoder down for two seconds, you will enter the m9XX’s options, turning the rotary encoder either way to change the settings or press down the rotary encoder to change the selected setting.
The 7-segment display is bright, large enough and easily legible in bright light as well as complete darkness.  You also have the option to turn off the illumination via “Display Dimmer Mode” setting (d.d. [dim] or dd [not active]).
The power up level is a thought out option; because you can set exactly what volume step you want the m9XX to start up every time.  I keep mine at “0” when it powers up.
The DAC filter utilizes four filter response modes, which are:
F1 = Sharp roll off, linear phase
F2 = Slow roll off, linear phase
F3 = Sharp roll off, minimum phase
F4 = Slow roll off, minimum phase
Here's more information regarding the filters:

To read more about the AK4490 DAC, you can peruse through this link:
I chose the default, which is the F1 = Sharp roll off, linear phase filter response mode.
0.08 Ω of output impedance – black backgrounds are par for the course.
The chassis and every part of the m9XX are made with high quality anodized aluminum and steel what looks to me like aircraft-quality materials.  Yes, it looks and feels that wonderful.
Power comparisons
My method of dB reading:
  • Perform tests in a quiet room or as quiet area as possible.
  • Set Sound Level Analyzer (Z frequency weighted) settings.
  • Use stock cables for tests.
  • Place microphone of iPhone 6 very close to the left earcup on all tests.
  • Make sure earcup is open and not laying on an object.
  • Run DAC/port Slim and m9XX at full volume (High gain, "90.").
  • Use -3 dBFS 192 kHz pink noise track.
  • A screenshot is taken of Sound Level Analyzer's "Lmin (dB)", "Leq (dB)" and "Lmax (dB)".
All measurements have been created with no EQ utilized.
I calibrated both DAC/port Slim and m9XX to emit the HE1000 around 81 dB with the Sound Level Analyzer (Z frequency weighted) as both DAC/amps were loaded with the same -3 dBFS 192 kHz pink noise track for sound quality comparison tests.  The HE1000 + DACport Slim needed about 1 1/2 full volume dial sliding upwards on High Gain and the HE1000 + m9XX needed "82." to reach as approximate the same sound level/volume as possible. 
Max volume of the DACport Slim and HE1000 using Sound Level Analyzer (Z weighting) and -3 dBFS 192 kHz pink noise track
m9XX + HE1000 with 1/4 to 1/8 in adapter
m9XX + HE1000 with 1/4 in cable
Sound impressions
I think the sound of the Grace Design DAC/amp is balanced and not overly or artificially boosted in any area of the frequency spectrum. The transparency of the presentation is apparent and immediate. It reminds me of food that tastes so invigorating, but hits the spot, is not too sour, not too salty, not too sweet, and not too spicy.  It tastes just right.  Compared to the DACport Slim, the m9XX is more coherent, resolving, clear and is able to retrieve micro, macro, and major detail in a more preferable manner.  The DACport Slim has more overall bass in its presentation, and the m9XX is more balanced and natural in its presentation. 
Disclaimer and hearing factors
The earphone and headphone reviews (brief or more in-depth) are mainly for anyone wanting a point of reference regarding how they more or less pair with the m9XX. 
We all hear differently, and our experiences with regards to how our interpretation of what we hear vary greatly.  Some factors that come to mind (and not limited), are: 
Your inner ear and skull’s overall composition:
Hearing loss as we age, also known as presbycusis,
Heredity, noise trauma, dietary habits, smoking, hypertension, atherosclerosis, are other factors that affect people’s overall hearing ability.
Select headphone/IEM pairings
Shure SE846 + SCS 

Tight.  Punchy.  Spacious.  Immersive!  The SE846 is a fabulous combination with the m9XX.  I personally do not detect a low treble rolloff.  I am using the SCS + Ted’s Silver Litz, plus black filter mod/white filter, so those mods/add-ons/replacements more than likely contribute to the veil of sorts being lifted.  Wow…wow.  I am listening to Seal’s Life On The Dance Floor via Tidal and m9XX, and it sounds so sweet and resolving.  Every bit of the sound spectrum, be it bass, midrange, treble, spatial capabilities simply ceases to amaze me.  The SE846 + SCS + m9XX are coherent and resolving without clutter, without mess.  I can go on and on, but this combination is a winner for those that want a clear and coherent sound with the extra bass kick for good measure.
Puro Sound Labs IEM500

When I met Jim Noyd at The Source A/V meet not too long ago, I just thought he would let me listen to the IEM500 as it looked pretty good on their website.  He gave them to me.  No mention of giving a review on them.  I wouldn’t have either more than likely if I didn’t like them, but these IEMs sound so lovely, that it would be a disservice not to say anything publicly about them.  A review will more than likely be forthcoming, but I need to say some thoughts about how they pair with the m9XX.  In one word: lush.  The overall sound is very rich, and I can tell the double dynamic drivers are working in full unison.  The bass is obvious, but not overbearing.  The midrange is liquid smooth, more like a vanilla shake from In-N-Out.  If too many food references are getting to you, let me know – but these foods are what comes to my mind.  The treble is laid-back and not harsh in the least.  The spatial capabilities, mainly soundstage, imaging and detail retrieval, are natural and present.  Intimate, yet spacious, are the words I would describe the IEM500 and m9XX combination.  Worth a listen, and worth purchasing, as I saw the prices of these on Amazon – wow!
Sennheiser Momentum In-Ear

This is the world premiere Momentum In-Ear in black chrome.  When I first listened to Jude’s maroon colored Momentum In-Ear for the first time, I asked him “How many drivers are in this?”  He said “Just one”.  I replied “Wow, I’ve got to get me one of these!” Thank you to Mr. Mahmood for supplying me with an IEM that I liked from the start, in exchange for my opinion.  I am simply enamored by this mighty single dynamic driver IEM.  I loved the maroon color of the original Momentum, but Sennheiser has hit it out of the park with a blingy, yet classy iteration of the popular Momentum In-Ear.  The m9XX turns this into a more balanced IEM.  The prominent midbass presentation still remains, but what a sublime midbass the Momentum In-Ear emits.  The entire presentation is warm, but gooey, like a tasty Cinnabon.  If you haven’t experienced a Cinnabon yet, you need to.  Okay, back to the fabulous sounding Momentum In-Ear.  The tonal balance of the midrange and treble is detailed, yet suave all at the same time.  Soundstage and imaging are not the strongest suits, but the crossfeed of the m9XX does an exemplary job of making the spatial capabilities of the Momentum In-Ear blossom to the best of its abilities. A great listen and warm sounding IEM, but opens up when paired with the m9XX.
Sennheiser Momentum 2.0 AEi

This headphone is already balanced and dignified via an iPhone.  Paired with the m9XX, the Momentum 2.0 AEi is a capable headphone.  I would like to thank Mr. Mahmood for sending over the brown version to me for my honest opinion.  What I like is the cups actually look like a dark metallic bronze color, very subtle, yet stylish.  If you check my earlier posts on Head-Fi, I posted that I did not like the original Momentum’s sound.  The update is more my cup of tea, to say the least.  I will not say exactly which headphone Sennheiser I do not like as much as the Momentum 2.0 AEi, but what I will say is that this headphone is relatively new, and I thought that I would like the headphone it since the description on paper seemed like something I may thoroughly enjoy.  Not quite.  This is okay, because the Momentum 2.0 AEi is cheaper than the particular headphone, and seems to be more of a coherent sounding headphone as well.  What I couldn’t have imagined is how much it would be liked by the people that have listened to it.  Against the MH30 and MH40, it was my fiancée as well as my brother’s favorite headphone.
There is a hint of midbass lift, but not nearly the amount of the Momentum In-Ear, for comparison.  The m9XX opens up the warmth in a meaningful manner.  The bass is tight and controlled, with not a lot of overhang.  The midrange – you can feel the texture, smooth like a rock that has been formed by the constant waves of the ocean.  The treble is easy-going, and should never be a concern with regards to fatigue.  The soundstage and imaging has opened, gotten better, like a wine that has been aged for 20 years, yet this transformation simply took a connection to the m9XX.  The Momentum 2.0 AEi is a thoroughly engaging involvement with the m9XX.

If I could describe what I am hearing with the HE1000 +Tidal + m9XX while listening to R.City’s Like This and R.City / Adam Levine’s Locked Away in one sentence, it would be the HE1000 is the personification of highly detailed, eerily spacious, utterly present transparency that is resolute and is effortlessly an immensely fine listen.  I am highly fortunate and grateful to have the ability to own this setup, and share it with whomever I meet in the world.
Closing remarks
Thanks to Grace Design for creating such an awesome DAC/amp and thanks to Will Bright and Massdrop for offering it at such an attainable price.  Thanks to @jude for not only bringing the glorious Grace Design x Massdrop DAC/Amp to our attention, but I would like to thank him for everything that he has done with regards to bringing the world of music and people together, one conversation at a time.
Thank you for reading, I appreciate every last one of you.
Grace Design x Massdrop m9XX DAC/Amp Specifications
THD+N at Maximum Volume, 1kHz, 22Hz-22kHz BW
0dBFS In, +14dBV Out = <0.002%
Intermodulation Distortion SMTPE/DIN 4:1 50Hz, 7kHz
@1.0V out, no load = <0.008%
@1.0V out, 32 Ω load = <0.009%
Frequency Response +/-3dB
Fs=96kHz = 0.5-45.9kHz
Dynamic Range
20-22kHz bandwidth = 112dB
20-22kHz bandwidth and A weighting filter = 115dB
Output Noise
20-22kHz, volume=0-90 = -106dBV
A weighting filter, volume = 0-90 = -109dBV
20-22kHz, volume=90.5-99.5 = -96dBV
A weighting filter, volume = 90.5-99.5 = -98dBV
100Hz = <107dB
1kHz = <98dB
20kHz = <72dB
Attenuation Range = 0 to -99dB, 0.5dB steps
Channel Tracking Accuracy = +/-0.05dB
Maximum Output Level = +14dBV (5.1V)
Headphone Output = 0.08 Ω
Line Output 47.5 = Ω
1kHz, -1dBFS, (0dBFS = +20dBu), 20-22kHz bandwidth = 0.0006%
Dynamic Range
20-22kHz bandwidth, 0dBFS = +20dBu (AES17 filter) = 117dB
20-22kHz bandwidth, 0dBFS = +20dBu (A-weighted) = 119dB
Input Lock Range
TOSLINK = 96kHz +/-1300Hz
USB = 44.1, 48, 88.2, 96, 176.4, 192kHz
Power Consumption
Max, High Power mode = 8.0W
Max, Low Power mode = 2.5W
Dimensions = 4” x 5.25” x 1.8”
Headphone Output Power
Low Power ModeOutput Power mWOutput Power mW
Load Resistance Ohms1 Channel Driven2 Channels Driven
High Power ModeOutput Power mWOutput Power mW
Load Resistance Ohms1 Channel Driven2 Channels Driven
Oct 23, 2015 at 6:34 PM Post #4 of 2,153

Nowadays, there's more headphone-oriented gear on the market than you can shake a stick at. Headphones are abundant. Headphone amps come in a wide variety of styles, prices, and topographies. And plenty of DACs now feature quality onboard headphone amplification. It's a headphone lover's dream.

Things were not always this way. Go back about 10 year, and there was far less of.... everything. In particular, if you wanted a quality all-in-one DAC/headamp solution, choices were rather limited. The major contenders came not from audiophile brands but rather the pro audio world. We had the Benchmark DAC 1, the Lavry DA10, the Grace Design Model 901, and - to a lesser extent - the Apogee Mini DAC. All offered what was considered at the time to be exceptional D/A conversion, with at least a reasonably nice headphone output, in a decidedly pro-audio oriented package. And the price on most of these approached $1k which was not a small sum back then. The Grace Design unit set itself apart by selling for $1,500 and by referring to itself primarily as a headphone amp - D/A conversion was also part of the deal, but the lack of analog outputs meant headphones were the only way to listen.

At the time, I cycled through all four models in my search for headphone bliss. I quickly eliminated the Apogee as being sub-par compared to the trio of Grace, Benchmark, and Lavry. All three models had their strengths and weaknesses, such that I enjoyed them all in their own way. This was a hot topic on forums at the time. It seems like many headphone enthusiasts were coming to the same conclusions I was: the Benchmark was crazy detailed but somewhat bright and unforgiving. The Lavry was creamy smooth and could be described as the most "analog" sounding. The Grace was perhaps the most balanced of the lot. All three models had their fans and a few detractors too, as is usually the case with most gear.

The m901 was my favorite option for driving my reference headphones, which at the time consisted of models like the Audio Technica L3000, Grado RS-1, and of course the Sennheiser HD600 which was standard issue for enthusiasts back then (and probably still should be). I wasn't in love with the 901's DAC portion, but the headphone stage was phenomenal. I often paired the Lavry as DAC with the Grace as amp, playing to the strengths of each model. Then along came the Grace m902 which I felt significantly improved the DAC section. While perhaps still lagging slightly behind the Lavry, it was close enough for me to sell the DA10 and stick with a one box solution for a time. It was also novel in having a USB input with which I took my first steps in computer audio. Very few devices had USB inputs at that time. But as other stuff hit the market I eventually moved on - you know how it goes. Grace had success with their m903 and more recently the m920, both of which seemed competitive in their field. I have heard both but not extensively. My point is, Grace Design has made catering to us headphone enthusiasts a priority for over a decade by now, so they have some expertise on the subject.

The range between $1,000 and $2,000 is jam packed with killer DAC/headphone amp combos. I'd say that's probably where you'll find the best value, in terms of gear that approaches state of the art but doesn't cost more than a new car. As you drop lower than that, it becomes more of an exercise in priorities. I'm not saying there aren't some solid devices out there. There's just usually some sacrifice involved. Maybe the headphone out isn't all that great. Maybe the USB implementation isn't on par with the alternatives. Maybe the amp does great with full size cans but doesn't play well with IEMs, or maybe it's the other way around. The trick is figuring out how to minimize weaknesses while packing in all the stuff us HeadFiers want most. Not a lot of devices nail those objectives.

One option, however, recently made its way to my audio rack, and it's worth talking about - the Grace Design m9XX. The product of a joint venture between Grace Design and Massdrop, the m9XX will go for $499 and should be available to order in a few days. It's a Massdrop exclusive, just like the AKG K7XX which I enjoyed so much - bonus points for sounding marvelous when paired together.

Now, for $499 I don't expect miracles from an all-in-one device. Typically we might get a pretty good DAC with a mediocre headphone amp, or vice versa. Not this time. The goal of the projects seems to have been packing most of the audio magic of the m920 (which at $1,999 is very highly regarded), stripping away many of the potentially unnecessary features, and ending up with a killer, somewhat minimalist device which performs way above its price.

While the m920 and previous generations were all half-rack sized (just like the Benchmark gear and many other popular DACs), the new m9XX is a compact little thing. At 4 inches wide, 5.25 inches deep, and less than 2 inches tall, this thing takes up very little space. Which makes it perfect for desktop duties where a larger device just wouldn't fit so well. I called the m9XX "somewhat" minimalist because, while it may lack quite a bit compared to the m920, it still has a reasonably advanced feature set considering the compact size.

Let's explore: on the input side we get XMOS-based USB capable of hi-res PCM as well as DSD64 and DSD128. There's also a Toslink input with the usual 24/96 cap. Outputs come in the form of RCA line-out as well as dual 1/4" headphone jacks, one of which automatically mutes the line-out when a headphone is inserted. Notably, Grace includes their proprietary crossfeed option for those who might find it appealing. This is a welcome feature as not many devices in this price range have the option. And Grace's crossfeed implementation has always impressed me, being less heavy handed than most - I find it particularly useful with older recordings using hard-panned mixes which clearly favor speakers over headphones, but it's subtle enough to use on modern mixes if the mood strikes. With certain headphones and music, it really does help bring the recording further "out of head", while in other cases it isn't as useful.

And that's about it. There really isn't much more room to add inputs or other options even if Grace wanted to. As it stands, they had to use micro-USB connections to save space. Yes, I said connections in the plural.... let me explain. The right side is what I'd call a "normal" USB input. It handles both power and data, allowing me to use the m9XX with my Surface Pro 3 without a mess of cables. This configuration gets us what Grace calls "low power mode" which delivers something like 160mW per channel RMS into a 32 ohm load, and roughly double that into 50 ohms. This is plenty for your Grado, Audio Technica, Ultrasone, and other sensitive headphones, and more than enough for pretty much every IEM on the planet. I also believe Grace Design is being careful not to boast using peak power, which is often done by marketing departments. If they wanted to sound more impressive they would mention the peak output for a single channel which is quite a bit higher. Need more power? That's why Grace supplies that extra USB input. By adding a second USB cable for power and using an adapter similar to a cell phone charger, the m9XX jumps up to over 1,000mW per channel at 32 ohms. Now we can run most planar magnetic headphones with very satisfying results. And with a corresponding boost in voltage we also get excellent sound with higher impedance models from Sennheiser and beyerdynamic. Again, very impressive considering the compact dimensions of this thing.

Let's talk user interaction, as I find it very well done here. The entire top of the enclosure is reserved for the multi-function knob which spins and presses to accomplish volume control and option selection. Hold it down to access the menu, which leads to options like crossfeed, startup volume memory, and 4 selectable digital filters. The display is a simple two-digit LCD with another small dot being used to indicate "on" or "off" for a function - see my pictures to help illustrate. It's a surprisingly simple yet effective system which I got the hang of immediately. The volume knob reminds me a bit of the old Ortofon HD-Q7 amp, which is quite a compliment with respect to aesthetics and usability. In fact, this entire design is somewhat reminiscent of that under appreciated little amp, which I've always felt absolutely nailed the design portion if not quite the sound quality category. The large button/knob on the m9XX is very precise, matching perfectly with the volume adjustment which is handled in .5dB increments. Overall the m9XX is a joy to use which isn't something I can say about every DAC, including some expensive models.

The heart of the DAC design is AKM's flagship AK4490 chip. This is a fairly new model, released within the last 2 years or so, and is not all that common as of yet. HeadFi folks probably recognize it most from its recent appearance in the updated Schiit Bifrost DAC where it replaces the older AK4399 used in the first gen model. It also shows up in the new (and rather expensive) Lindemann Musicbook series. Aside from those two brands, I'm not aware of anyone else using it thus far. AKM DACs in general don't seem to be used as often as Wolfson, Cirrus, TI, and ESS, so it's hard to know what to expect. Of course, the DAC chip itself is only one small piece of the puzzle, so maybe it's best we don't come into this with preconceived notions anyway.

I already mentioned the XMOS USB implementation, which ends up processing the Toslink input as well. A unique hybrid analog-digital phase-lock loop system (PLL) helps reduce jitter which is especially useful for Toslink, being more likely fed by a lesser source such as an Apple TV. Extensive power filtration is employed to make sure the noisy USB connection isn't fouling things up. Grace uses a total of 5 power supplies including separate supplies for the XMOS implementation, the DAC, and the analog stage. 5V USB power is converted and augmented by a proprietary system allowing the device to run +/- 9V rails on basic USB power, and +/- 14V when running in high power mode with the power adapter. I won't go into it too far but again this shows the expertise involved, especially for a small and relatively affordable device such as this.

The headphone output is built around a Texas Instruments THS6022 transimpedance/current feedback amplifier. I have not seen this particular chip used in this application before. More typically, we see chip amps based on either the TPA6120A2 (quite powerful but usually requires 10 ohm output impedance for stability) or the TPA6130A2 (stable at lower output impedance but far less powerful). Nothing wrong with either, but I was pleased to see something unique being used which seems to combine the best of both the TPA options. Output impedance is well below the magic 1 ohm mark - at 0.08 ohms, listeners have nothing to worry about even with IEMs sporting wacky impedance curves. And I already mentioned the output which is very robust indeed.

Now, after all that, how does the m9XX perform? In my humble opinion: it's really something special. Neutral, resolving, clean-as-a-whistle, the m9XX is an excellent monitoring tool. Paired with a nice set of active monitors, this setup allows one to hear deep into the mix, with a level of transparency few compact DACs can match. It pairs quite well with the AMT tweeter in my Adam Audio F5 monitors - a tweeter known for its expressiveness, not to mention ability to expose sources with poor timbral accuracy. Top end air and extension are without reproach, making it hard to believe this DAC/speaker combo sells for just a bit over $1k. I've heard big rigs using expensive/exotic speakers which utterly failed at reproducing the brassy tones of a trumpet, the shimmer of a crash cymbal in all its glory, or the quick attack of a piano strike The m9XX/Adam F5 combo excels in all three of these tests, proving one needn't spend a fortune to achieve lifelike sound.

Despite its clarity, I wouldn't necessarily characterize the m9XX as a clinical, dry sounding DAC. It's got enough resolution to pull out gobs of microdetail, but it also maintains a connection with the music which is lacking in many pro-audio style DACs. The result is closer to what I remember from the old Grace 901 - balanced, organic, well rounded, not lacking in detail but not shoving it down your throat either. I actually think the little m9XX would compare favorably with the original 901 in terms of DAC performance - that would be a fun comparison if I still had a 901 around. Unfortunately I don't, but I do have several more recent DAC comparisons which might help illuminate the flavor of this device.

The Parasound Zdac V2 ($549) is a very enjoyable DAC. It falls on the warm and smooth side, with a dynamic punch that may exceed what the m9XX can offer. In contrast, the Grace unit is more resolving, cleaner, and more airy in tone, with a more precise soundstage and accurate imaging. I really like both models and would choose among them based on what associated gear makes up the system.

The Rega DAC-R ($1,195) is also a warm and smooth DAC, but I find it troublesome in that it lacks the dynamic bombast of the Parasound, while going even farther into warm/smooth territory. Consequently, it feels like a wet blanket, where music just plods along with no emotion. It can be helpful for taming bright systems but that's about it. The Grace m9XX is superior in most every way, to the point of this really being no comparison. I know a few people who really enjoy what this DAC does, but I just don't hear the appeal based on extensive listening. Maybe my unit is a dud.

The Musical Fidelity MX DAC ($999) is the first Musical Fidelity product I've actually enjoyed in quite some time. I'm told there's been some restructuring at the company and some new blood brought in - hopefully this brings about good things, as Musical Fidelity used to be a big player in the headphone world with their compact X-series components. The MX is a very pleasant DAC where nothing stands out as objectionable - a good thing considering the funky performance of the previous M1 DAC and its variants. The more I listen, the more I like it, and find it very similar to their $2,500 M6 CD player I used to own - perhaps even better. By comparison, the m9XX is just as transparent, just as engaging, and at half the price, is a far better value. And that's before we consider the headphone amp functionality. Bottom line is that I really can't tell these two apart, so there's no way I'd spend double on the MF product, despite it being a very competent offering. If you needed balanced outputs or wanted to stack with the Musical Fidelity MX-HPA headphone amp, the Grace wouldn't work as well, but that's about the only situation I can think of where I wouldn't get the smaller m9XX and call it a day.

MicroMega's MyDAC, at $399, is one of the few devices here small enough to look like a direct competitor to the m9XX. Unfortunately it sounds like there were some compromises involved in achieving this small form factor and low price. It has a focus on transient attack which initially makes for an exciting sound signature, but ends up overwhelming with a busy presentation that becomes unbalanced during long term listening. This is one of those devices that you first demo and think "Wow, I love it!" but later come to hear as fatiguing. The m9XX initially seems a tad boring in comparison, with its measured, even-handed approach. Where's the bite, the snap of the music? After a short time it becomes clear that the m9XX is actually more lifelike, more organic, while the MyDAC is a neon facsimile of reality. This thing received some rave reviews a few years back, and I actually believe those reviewers were genuine in their assessments... they just threw the device in the system, listened for 20 minutes, wrote it up, and moved on. That's why I spend as much time as possible with my listening, sometimes even missing the window of new-product-buzz. I like to be confident in what I'm hearing and that sometimes takes longer than you'd expect.

$500 doesn't buy all that much performance in absolute terms... and when it does, you're typically looking at a dedicated DAC or headphone amp by itself rather than a combo unit like this. So how about that headphone output - is it compromised as we might expect for the price? Thankfully, no. The m9XX sounds very satisfying driving headphones directly. Just like the DAC portion, it strikes an excellent balance between accuracy and musicality, and pairs well with nearly every headphone I have on hand. I'm actually rather surprised at how well it does considering the size of this little box. Apparently Grace knows their stuff.

Straight from a single USB connection which translates to low power mode, the headphone out is exceptional with IEMs. I get a mild, very tolerable hiss with my EarWerkz Supra, JH13 FreqPhase, and Unique Melody Merlin, which my brain easily filters out once the music starts. The rest of the IEMs in my collection play with an essentially silent background: Noble Audio K10, 5C, 4C, and Savant, Dunu Titan, Lear LCM-5 and LCM-BD4.2, the Aurisonics AS-1b, and many others which I'm forgetting at the moment. A volume setting of roughly 50 (out of 99) is typically good for most music, leaving plenty of room to dial in more or less as needed. I'm a huge fan of custom IEMs and it can be frustrating when so many amps - somewhat counter intuitively - can't handle these easy-to-drive little things. I'm happy to report the m9XX passes the test with flying colors. A top-level CIEM can be as resolving (arguably more so) than the best full size headphones, and will often expose weaknesses in a source. Again, the m9XX passes the test with aplomb.

Moving to full-size headphones, the m9XX does a very competent job as well. As I mentioned earlier, some models do just fine in low power mode. The Astell & Kern AK T5P, a rather sensitive flagship closed back headphone, is extremely enjoyable with the m9XX set to volume 60-70. If this was my main headphone I wouldn't ever use the high power mode. Same with the Grado PS500 and the Sony MDR-1A. Of course, driving current-hungry planar magnetic cans like the Audeze LCD-2 provides an obvious excuse to run that second USB cable with the power adapter. Note that gain remains the same, but drive is enhanced. So running the LCD-2 in low power mode with the m9XX already gets me all the volume I could ever need. But the bass performance is weak, and the midrange lacks focus. The whole thing is just soft and squishy. It's clearly underpowered. High power mode doesn't suddenly let me run at lower volume settings, but it does give a clear increase in drive. The LCD-2 regains its authority, with deep, clean low notes and a more insightful midrange. This same experience applies with the HiFiMAN HE-500 and Mr Speakers Alpha Dogs too. There's enough juice on tap in high power mode to get most planar magnetic headphones jumping, with the usual exception of Hifiman's HE-6. I also prefer high power mode with my Sennheiser HD650 and other high impedance models. Interestingly, I even prefer high power mode when driving the AKG/Massdrop exclusive K7XX. It's not the most demanding headphone out there but seems to really "wake up" in response to the extra power. It's handy to have both options available.

Overall the amp section is nearly identical to the DAC - both are clean, transparent, and highly resolving, yet not analytical or dry. The end result compares favorably to any number of more expensive devices I can think of. The original Benchmark DAC 1 for example, is more chalky and etched sounding to my ears, with a glare to the upper mids and a thin character that just don't enjoy these days. When it first launched back in the day, I admit to being taken by its seemingly extreme resolution, but I eventually began to hear it as artificial and obnoxious. Their DAC 2 is far superior to its predecessor and does manage to outclass the m9XX, as it certainly should for the price. The delta is not as large as you might think though. I also prefer the m9XX to the Mytek Stereo 192, which to my ears sounds dangerously close to the original Benchmark DAC 1. The Grace model has more life and soul, sounding better no matter what headphones or speakers I pair it with. The best comparison I can probably think of is the Anedio D2 which was selling for $1,249 last I checked, down from the original $1,470. The little m9XX gives a huge portion of the same ultra-transparent, open-window type of sound, at a far lower price and in a smaller package. I still find the D2 superior but spotting a difference requires some careful listening with excellent recordings - most people would find them very similar under normal circumstances. Those who know my opinion of the Anedio will understand just how big a compliment this comparison really is.

I never intended to turn this into such a long write up. I've got paid articles in progress for InnerFidelity and Part Time Audiophile which I really should be focusing on. But this little device gets me optimistic about what can be achieved through smart engineering and knowing what users are looking for - and what they aren't. Grace Design seems to have whittled down the technology and features of their far more expensive m920 in just the perfect way, while Massdrop allows it to be sold without a huge dealer markup. The initial drop is limited to 500 units and I suspect those will go very quickly - I'm hoping (though I have no verification at this time) that Massdrop will offer more drops in the future just as they have done with the K7XX. In any case, here I am rambling on and on about it instead of working on my "real" articles. Jude will have his say on the m9XX, as will several other experienced HeadFiers, so we'll see if my experience matches theirs. All I can say is that I'm thoroughly impressed by this thing, and think it might be a new benchmark (no pun intended) in terms of sonic results for the price.

Oct 23, 2015 at 6:57 PM Post #5 of 2,153
Sounds promising and also looks good.
Oct 23, 2015 at 7:06 PM Post #6 of 2,153
Hey Everyone,
Nearly a year ago, we launched our first collaboration, a project I lead with AKG. Our goal was to redefine price to performance expectations for open back desktop headphones at the $199 price point. Judging by reviews and related threads, it’s hard to say we missed the mark. The success of that product was a proof of concept. We validated the idea that we could go beyond selling products, breaking into the realm of production and involving dedicated community members to design the products they want.
Since then, we’ve worked with a number of manufacturers to create and release products based on feedback from the enthusiast community at large. Some of them are co-branded, some are labeled “Massdrop Exclusive”, and some are made by contract manufacturers at our behest. All of them have been successful, and all of them have offered an exceptional value to customers, attracting Audiophile and laymen customers alike.
In January, I contacted Grace Design about the prospect of working together to create a new product. Something that would take all the audiophile components from their m920 (flagship headphone mastering system, ~$1500), improve them where possible, and bring the product into an accessible price range.  See, the trouble with the m920 was that, while it’s a world-class DAC/Amp, it has tons of hardware that’s only useful for Pro Audio applications (special interfaces with steep licensing costs, etc). Even still, the m920 sold exceptionally well among audiophiles (especially on massdrop) looking for the highest resolution DAC implementation and cleanest solid state amplification.
With the m9XX, we’ve achieved our goal, bringing the price down to $499 shipped in the united states, while maintaining the m920’s performance level for Audiophile applications, as evidenced by measurements and subjective impressions alike. To do this, Grace had to innovate on nearly every aspect of the design. Grace built a trans-impedance amplifier with an output impedance of just .08 ohms and no capacitors in the signal path. They created a dual power supply allowing use as a portable USB powered device while delivering over 1 watt of power per channel into a 32ohm load with both power supplies engaged. We built the most satisfying volume control on any audiophile device (digitally stepped volume control, light tactile bump at every half db with subtle but audible click, low enough resistance to spin comfortably).
Ultimately it’s your job to decide if the product we made is worthwhile, and I can’t wait to hear what everyone has to say. That said, rather than just casting your opinions into the nether, how about you go one step further and think of a question to ask the designers.
Starting now, and ending on Saturday night, I’ll be collecting questions from this thread, and on Sunday I’ll post all the answers, straight from Grace (and Massdrop where applicable) right...

HERE (I’ll edit this post and add the Q/A)
Put on your thinking caps, man your keyboards, quit lurking, and ask something only you’re clever enough to think of. This thread is your line straight to some of the best audio device engineers alive, I’d make use if I was you.
In the meantime, take a look at the drop, read the description, and let me know what you think!
Drop launches Monday the 26th!
- Will
Edit: Added bonus, unboxing vid from HifiGuy!

Oct 23, 2015 at 8:52 PM Post #8 of 2,153
Hey Will,
Congrats on another great product launch!
I really love the LED volume display.  Its a rare thing to see on headphone amps of any price.
Here's a question you may already know the answer to: is the volume attenuator a digitally-controlled analog design or is it a DAC-controlled purely digital design?
Oct 23, 2015 at 8:55 PM Post #9 of 2,153
Would love to see this in a cage-match with the newly released Chord Mojo!
Oct 23, 2015 at 8:57 PM Post #10 of 2,153
I totally do not need this amp. But I totally want to get in on the drop of this amp ... -lol

Someone, talk me into, or out of it! :D
Oct 23, 2015 at 9:13 PM Post #11 of 2,153
Any chance of a tete-a-tete with the Element?  When I saw the design of this amp, my immediate thought was, Hmmmm, haven't I seen that somewhere recently?
Oct 23, 2015 at 9:15 PM Post #12 of 2,153
The m9XX attenuator is a hybrid design. Most of the volume control duties are handled in the digital domain with 32 bit processing but there are two analog gain ranges. This allows a full 98dB of volume control range, preserves a very low noise floor for IEMs, and allows high peak output voltage for low efficiency planar magnetic phones.
Oct 23, 2015 at 9:30 PM Post #13 of 2,153
  Hi XERO1,
The m9XX attenuator is a hybrid design. Most of the volume control duties are handled in the digital domain with 32 bit processing but there are two analog gain ranges. This allows a full 98dB of volume control range, preserves a very low noise floor for IEMs, and allows high peak output voltage for low efficiency planar magnetic phones.

Thanks Michael.
So if I wanted to use the m9XX as a DAC, what volume level would I need to set it at to achieve an approx. 2V output level from the RCA output?
Thanks again.
Oct 23, 2015 at 9:50 PM Post #15 of 2,153
Any chance of a tete-a-tete with the Element?  When I saw the design of this amp, my immediate thought was, Hmmmm, haven't I seen that somewhere recently?

I'd also be interested in this and how this amp works with the th900 and it's somewhat harsh treble.

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