[WilliamLeonhart]

  They do sound similar. I'd say, just from my experience, the m9XX is a bit less detailed at the top end and has a wider soundstage. Whereas the Mojo is a bit more accurate across the board and has a slightly more closed-in soundstage. As with most things in this field, you have to make a personal determination between "fun" and "technical" and what's right for you. Also, the cans you hope to pair them with.
 
The big differentiator is feature-set and form factor. Leaving the m9XX on all the time and having it connected to phones and speakers simultaneously is a lot easier than with the Mojo. I can leave most things plugged into the Grace. The Mojo is a lot more portable and isn't really meant to anchor a desktop solution.

Sounds the same as what I'd say about the M9xx vs the iDSD Micro. I'm very happy with both.

 

[jincuteguy]

Anyone knows if this Grace D m9XX is better than the Teac 501 or the ifi Micro iDSD ? thx.

 

[WilliamLeonhart]

The TEAC I can't tell but the iDSD is IME less musical than the m9XX and the Mojo. The iDSD is more neutral but its trebles spark and pops more, thus it's better for music where I'd like to enjoy trebles like Metal, Rock or Classical. The m9XX is pure music enjoyments. "Natural" is the first world I'd use to describe it.

 

[Spork67]

SWMBO likes me to have a beer-free month every now and again, and had declared that July will be dry.
Soooo - I've joined the latest drop... The $ I save on beers will help finance it.
It should arrive about the same time or a little before the drought breaks.  I can't wait!

 

[Decommo]

Finally pulled the trigger and ordered M9xx. Has anyone upgraded usb cable to connect to computer? Does it improve sound quality by any measure? Not sure if it is worth to upgrade USB cable... Any feedback would be greatly appreciated.

 

[fjrabon]

  Finally pulled the trigger and ordered M9xx. Has anyone upgraded usb cable to connect to computer? Does it improve sound quality by any measure? Not sure if it is worth to upgrade USB cable... Any feedback would be greatly appreciated.

the cable they send is a good cable.  If you are using it in high power mode, you probably won't hear any benefit to upgrading the cable, because in that mode power and data are completely separated (other than small power impulses used for coordinating the signal).  The only times I've ever had issues with USB cables is when the unit was being powered by the same cable delivering data.  If you are using USB bus power (ie low power mode) then you may benefit from a better shielded cable, but even then probably not.  

 

[Decommo]

 

  Finally pulled the trigger and ordered M9xx. Has anyone upgraded usb cable to connect to computer? Does it improve sound quality by any measure? Not sure if it is worth to upgrade USB cable... Any feedback would be greatly appreciated.

the cable they send is a good cable.  If you are using it in high power mode, you probably won't hear any benefit to upgrading the cable, because in that mode power and data are completely separated (other than small power impulses used for coordinating the signal).  The only times I've ever had issues with USB cables is when the unit was being powered by the same cable delivering data.  If you are using USB bus power (ie low power mode) then you may benefit from a better shielded cable, but even then probably not.  

 
Thank you very much for the info. I am looking for short cable (less than a foot long) to connect between laptop and M9xx. 6ft or 8ft cables are too long for me. I will be using USB bus power because I do not have any hard to drive headphones. Will any short length 2.0 USB cable work?

 

[fjrabon]

Thank you very much for the info. I am looking for short cable (less than a foot long) to connect between laptop and M9xx. 6ft or 8ft cables are too long for me. I will be using USB bus power because I do not have any hard to drive headphones. Will any short length 2.0 USB cable work?

1) yes any decent quality USB cable with a ferrite bead should be fine.
2) the m9XX, to me, does sound better in high power mode, if it's possible for you, because having a "clean pipe" for data only does seem to make a difference. It's not actually the increase in power that matters for most people, but rather that the data and power are better managed when they're kept separate.

 

[jwbrent]

Joined the drop.

 

[Decommo]

Thank you very much for the info. I am looking for short cable (less than a foot long) to connect between laptop and M9xx. 6ft or 8ft cables are too long for me. I will be using USB bus power because I do not have any hard to drive headphones. Will any short length 2.0 USB cable work?

1) yes any decent quality USB cable with a ferrite bead should be fine.
2) the m9XX, to me, does sound better in high power mode, if it's possible for you, because having a "clean pipe" for data only does seem to make a difference. It's not actually the increase in power that matters for most people, but rather that the data and power are better managed when they're kept separate.

Great to know.. Thank you very much.. I will use high power mode.

 

[WilliamLeonhart]

It's a bit confusing for me. In what mode will the m9xx use battery power?
In high power mode will it affect the amp section too or just the DAC?

 

[Spork67]

My understanding is that in low power mode (ie: one USB plugged in) it will receive both the signal and the power from the device on the other end of the USB
In "High power mode" (both USB's connected) it receives the power from the 2nd USB and the 1st one just sends the signal (maybe some power also???)
The 2nd USB should ship with a 110v /230v (depending where you live) plug for the wall, however it is possible to connect this to a battery / power pack that has a USB connection, to:
- make the whole thing portable, in high power mode.
- Provide the "cleanest" power source.
From what I can tell there are probably better choices for portable use, and the "clean power" may or may not make any difference to you. A battery is simply an option.

 

[fjrabon]

My understanding is that in low power mode (ie: one USB plugged in) it will receive both the signal and the power from the device on the other end of the USB
In "High power mode" (both USB's connected) it receives the power from the 2nd USB and the 1st one just sends the signal (maybe some power also???)
The 2nd USB should ship with a 110v /230v (depending where you live) plug for the wall, however it is possible to connect this to a battery / power pack that has a USB connection, to:
- make the whole thing portable, in high power mode.
- Provide the "cleanest" power source.
From what I can tell there are probably better choices for portable use, and the "clean power" may or may not make any difference to you. A battery is simply an option.

Yes, you can plug the 2nd USB into a portable battery.

 

[fjrabon]

It's a bit confusing for me. In what mode will the m9xx use battery power?
In high power mode will it affect the amp section too or just the DAC?

The m9XX doesn't have a battery. You can power it with a portable USB charger. But it doesn't itself have a battery. High power mode will allow the "second stage" amp to turn on and give you about twice the power (roughly 3dB more volume)

 

[m8o]

It's actually closer to a 10db increase in audio power at the lower impedances, and power multiplier decreases as the impedance rises, where the current draw is less necessary and it would be more helpful to have higher voltage swings but not possible from the 5V adapter or battery pack:

Headphone Output Power - Low Power Mode (2 channels driven)

22 mW @ 4 Ω
45 mW @ 8 Ω
90 mW @ 16 Ω
100 mW @ 20 Ω
175 mW @ 32 Ω
280 mW @ 50 Ω
83 mW @ 300 Ω
40 mW @ 600 Ω


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

Pretty significant power output from this little device. And it stays clean all the way up to the rating. (But then like any IC device is pure high order harmonics should you exceed it's drive capabilities -haha)