Massdrop x Grace Design m9XX DAC/Amp Discussions | Drop

Jun 21, 2016

Jazz1They sound VERY similar. The Mojo is maybe a touch smoother and the m9XX a touch more dynamic. But I'd say they sound 98% identical. I had both at the same time for about a month. I tell most people who ask me to pick between the m9XX and Mojo based on what features and form they want, because the sound quality is basically a dead heat.

decommo

Jun 27, 2016

fjrabonThank you for sharing. I am about to purchease either Mojo or M9xx and could you explain a bit more about feature difference? I understand that form is very different and one is truly portable and the other is not. However, I am not sure what feature differences between the two. Thank you.

Jun 27, 2016

decommoThe m9XX has a very good built in analog crossfeed circuit. The m9XX has 4 different filters (the filters are extremely subtly different though and are mostly to address issues in aliasing and phase incoherence, they're not meant to change the tonal character of the amp). The m9XX has push button mute. The m9XX has RCA outputs that have an auto mute function when you plug a headphone into the right headphone jack.

Decom

Jun 27, 2016

fjrabonThank you very much. It was very helpful :)

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Jul 19, 2016

fjrabonThanks for some input on sound comparison between mojo and m9XX . I already have chord mojo and it is excellent. would there be any point in getting m9xx? I am asking in terms of does it sound different, more warmer or have a cleaner sound? what about the crossfeed and multiple anti-aliasing filters, do they give m9xx an edge over mojo?
I have seen people talking here about if m9xx can drive higher impedance headphoens such as HD800 or beyerdynamic T1(600ohms). My only comment regarding this is that Mojo drives both HD800 and T1 flawlessly and effortlessly(I don't own any of tehse 2 headphones but have tried them with mojo in an audio store) and as I have understood that m9xx outputs more at 600ohms, so why m9xx would have any trouble driving HD800 or T1 ? Am I missing something here or did I not understand these outputs correctly(as I am no expert in these)?
Mojo's specs from its manual shows (http://www.chordelectronics.co.uk/mojo/manual/Mojo-User-Manual.pdf)
MOJO: Output Power @ 1KHz 600 OHMS 35mW 8 OHMS 720mW Output Impedance: 0.075
m9XX specs as posted in thsi drop:
m9XX Headphone Output Power - High Power Mode (2 channels driven)
240 mW @ 4 Ω 490 mW @ 8 Ω 940 mW @ 16 Ω 1030 mW @ 20 Ω 950 mW @ 32 Ω 650 mW @ 50 Ω 115 mW @ 300 Ω 57 mW @ 600 Ω Impedances
Headphone Output: 0.08 Ω Line Output: 47.5 Ω

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Jul 19, 2016

zubairomThe m9XX drives the HD800 perfectly fine power wise, it's what I'm listening to exactly at this moment. Some people like a tube somewhere in the HD800 chain to add some 2nd harmonic tube-ness into the mix and smooth things just a bit more. As you note, the m9XX will drive the HD800 at least as good as the Mojo does. Now if you listen at insanely loud levels and EQ, you might run into issues (I have a friend who was listening to them the other day at 99.5, to be that almost exploded my head).
When I'm not EQing I am usually on 65-75 on the m9XX. When I have EQ engaged I usually need 10dB more amp headroom to avoid clipping, so I have the m9XX on 75-85 most of the time. I basically never go over 90, even when EQing. While I prefer high power mode because I think it makes the power supply and data streams a bit cleaner, the m9XX can actually power the HD800 just fine in terms of pure power needed in low power mode.
Honestly there are next to no easily discernible differences between the m9XX and Mojo sound wise. The filters don't really change the sound much, if at all, and are more to solve various issues you may have with certain music and in certain usage scenarios (intermodulation distortion and aliasing distortion) than to change the flavor of the m9XX's sound.
The crossfeed on the m9XX is to me, a big advantage. I don't use it very much because I tend to use the Goodhertz plug in, canopener, because it has greater flexibility: I can change the amount of crossfeed, the perceived angle of crossfeed and the type of crossfeed. And then I can use mid-side matrix to widen (or theoretically tighten) the soundstage width. However, the Grace's crossfeed is nice when I'm in a scenario where I am using my iPhone as the player source. Since I've yet to find a player that I am happy with streaming that also has crossfeed, I can use the m9XX's crossfeed in those scenarios, and while I prefer Goodhertz, I think the m9XX's crossfeed is very well done, and I much prefer it to not having crossfeed (the disconnected soundstage headphones have without crossfeed drives me crazy).

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Uzuzu

1431

Jul 19, 2016

zubairomI really don't think the m9xx is suited well for beyer or senn cans. Of course it will be fine if you use it as a Dac and have it plugged into a more powerful amp. HD650 sounds bad on it. My DT150s sound better and are easier to drive at 250 ohms, but still lack fullness in the low end. Even when the grace is used as a dac and plugged into cheap amps even under the 50 dollar range (that have reasonably clear sound) and that also have more voltage output, I find that those high impedance headphones sound a lot better and by a very noticeable margin....

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Jul 19, 2016

fjrabonThanks for your detailed reply and comparison.
My headphones are SONY MDR-Z7 (70 ohms) which have excellent bass, and I pair them with mojo with iphone6 as the player. I don't think I would have any trouble pairing it with m9XX however do you think there would be a significant advantage getting m9XX when I would not be doing any additional EQing or using Goodhertz plug in for crossfeed ?

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Jul 19, 2016

Uzuzu:) thanks for replying. Obviously there are some major differences in opinion here on the m9XX and high impedance headphones .. I really don't have to worry as I don't own either T1 or HD800 ...

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Jul 19, 2016

Uzuzuif you're talking about "lacking fullness in the bass" you're either talking about wanting an output impedance induced bass hump or adding 2nd harmonic distortion with a tube. It certainly doesn't need a "more powerful" amp. Unless you're playing music at 120dB you aren't even close to running out of power. Having more power doesn't add "bass fullness." An amp either has enough power to run without distortion or it doesn't and the Grace certainly has enough power to run the HD800 at 120dB without distorting.

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Jul 19, 2016

zubairomUnless you find the Mojo inconvenient to use or you want crossfeed, I definitely don't think it's an upgrade you need to make. The pure sound quality will be exactly the same. Even though the m9XX has twice the power, that's only worth 3dB of increased headroom, which with the Z7 shouldn't be something you need anyway.
I owned the Mojo and m9XX at the same time and the deciding factor for me was feature set and design, rather than sound quality. The sound quality was a dead heat. And the m9XX's increased power wasn't a big deal.

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Jul 19, 2016

fjrabonmojo is great, I love it. Just as you said I am also interested in m9XX because of its features and design.
With mojo I have noticed that sound does get distorted (mid-range especially) at very high volume levels, with Z7 and even with T1 and Fostex Th900 when I tried mojo with those, what does it really mean, too much power, or lack of it? or something else? ideally I would expect the sound to stay solid and tight for all frequencies even at a very high volume .. would a better amplifier or better pairing help in that?

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Jul 19, 2016

zubairomnot sure, could be the amp, could be the headphones. I was never able to actually listen to the Mojo at high enough volumes to distort without the actual physiological distortion in my ears (ie my ear drum literally distorting) kicking in first. Also it's weird that you're saying the midrange is distorting, as usually it's the bass where that happens first, as most headphones have more bass distortion and bass requires more power for a given SPL. My intuition is telling me the distortion you're hearing is your ears and not the headphones or amp, but I have no idea without experiencing it.
I can say that I have never pushed my m9XX hard enough to hear amp based distortion. All the way up to 95 it remained clean. I have never been able to listen to it over 95 with any headphone and any recording and/or EQ setting.

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Jul 19, 2016

fjrabonYou are probably right about bass, as I wasn't sure if it is mid or upper bass or mid-range(or where they overlap I guess) that I felt was getting distorted. It could be my ears, how can I tell if it is physiological distortion or amp based distortion? maybe I just increased the volume too high where it gets unbearable...
In another reply you mentioned "An amp either has enough power to run without distortion or it doesn't" , what do you really mean by that?

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falcoxx

Jul 20, 2016

fjrabonSo if the sound level is high enough with your current amp, without maxing the volume, there would be no reason to upgrade to a more powerful amp unless you want more features, smaller size or a different sound signature?

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Jul 20, 2016

falcoxxwell, other aspects of an amp to evaluate are: quality of power supply, output impedance, THD level and THD breakdown (ie what harmonics the distortion is in), crosstalk, channel balance, preservation of spatial cues (really this is part of THD, but I think of it separately), diaphragm control, and many others. However, total available power is only a very crude proxy for any of these. It drives me nuts when people assume a certain amp is better because it has more power available, when the headphone they're using it with would never even come close to using that amount of power at the user's listening levels. Like some people think that a 4 watt amp will be more dynamic than a 2 watt amp with the HD800. Nonsense. You are never even gonna come close to using 2 watts on a HD800 unless you're trying to blow your brains out. Really, the vast majority of the time you only need about 100mW for the HD800, if the power is regulated well.
Buy a good amp that meets the needs of your headphones, don't just blindly buy a powerful amp. Total power ratings are usually the least important spec you could find for an amp (which of course means they're the most commonly published specs, since they're the least useful).

Jul 20, 2016

zubairomeither the amp is running out of current or voltage and thus distorting, or it still has available current or voltage on tap. That's the only measure of whether or not an amp is powerful enough. Very rarely do people actually run out of current or voltage on their amps, what they believe to be a lack of power is really something else about the amp that is showing up more clearly at higher levels, but isn't a lack of power.

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falcoxx

Jul 20, 2016

fjrabonThank you. That helps a lot!

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Jul 20, 2016

fjrabonhow do you compare an amp like mojo or m9XX with a decent tube amp? for headphones like Z7 or Th900? which one is a better pairing? also what would be the right setup for punchy tight bass that does not get distorted even at higher volums?

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Jul 20, 2016

zubairomDepends on what you mean by "decent tube amp." I think the Torpedo III is better for the Z7 and TH900 than the m9XX by a small amount, but it's a $900 amp that you have to build yourself (it's like $1300 and still a crazy good value at that if you get Tom to build it for you). If by decent tube amp you mean the bottlehead crack, then I think the m9XX and Mojo are better. The crack's output impedance is just too high for those headphones and their bass will bloat and they'll lose diaphragm control. The midground is something like the Lyr2. There I think it's much more a matter of preference.
Generally I think the TH900 works better on a solid state zero impedance design amp, but it really comes down more to the specific amp than tube vs solid state. The TH900 sounds pretty harsh to me out of a Magni, for example.
to get "punch tight bass that doesn't distort at higher volumes" you want:
1) a headphone with very low distortion numbers in the bass range. The TH900 certainly qualifies there 2) an amp that imparts more 2nd harmonic distortion than higher order distortion. A really good tube amp does this. But also some solid state amps do it as well (m9XX and Mojo both do). 3) a good power supply 4) a quality 64 bit EQ program. (optional if the headphones doesnt naturally have the bass you're after).

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Pahani

118

Jul 21, 2016

fjrabon" Nonsense. You are never even gonna come close to using 2 watts on a HD800 unless you're trying to blow your brains out."
Sadly, too many people are still cranking the hell out of their headphones and amps on a regular basis. TURN IT DOWN, FOLKS!!! Single-song rock out sessions are fine...2-hour marathons are not.
You WILL damage your hearing in the long run listening at excessive volumes. You can still have a satisfying listening experience at relatively modest levels. Keep it turned down, and you will thank yourself in your later years :)

Jul 22, 2016

fjrabonthanks again for the reply..
I really like the mojo and there is probably not a better portable amp than mojo. The only thing I felt is that with some recordings , the mids and highs got a bit two sharp and was harsh on ears, at mid to high volumes. Bass got distorted probably because i just turned the volume too high.
Yesterday I had a chance to try out WA6 with mojo as a dac with iphone and it did exactly what I was hoping for, took off the sharp edges, made the sound a bit warmer and vocals sounded a bit more real.. I liked the WA6 pairing with mojo(as dac) .. How do you compare WA6 to the tube amps you mentioned about (Torpedo III and Lyr 2) ? Also how would you compare WA6 to other Woo Audio tube amps like WA7 WA3 and WA2?

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Jul 24, 2016

zubairomI haven't heard the WA6. I've heard the WA7 and was disappointed. Lacked clarity and wasn't very dynamic. I honestly thought my HiFiMan EF2C was better.

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Jul 26, 2016

fjrabonYou are probably right about WA7 as I have not read many good reviews about it, however people seem to like WA2 ( bit more pricey) a lot..
Has you ever had a chance to try Marantz HD - DAC1 Headphone amp? It sure looks nice and very well built, and I have read good things about it. Any idea how does it compare to m9XX?

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