Grace Design m903, reference headphone amplifier, DAC, monitor controller

From http://www.gracedesign.com/products/m903/m903.htm

It seems like a m902 update with better USB support, otherwise the specs are very close to the m902.
Price point: 1700/1800 $

• Balanced and unbalanced analog inputs
• 24bit/192kHz digital stereo inputs- AES3, S/PDIF, TOSLINK and USB
• High speed USB interface - completely asynchronous transfer mode allows for bit-perfect playback with zero interface induced jitter
• Driverless operation on Windows & Mac up to 96kHz/24bit
• Supports USB Class 2 audio specification for 192kHz/24bit operation on Windows & Mac (drivers needed for 192kHz operation under Windows)
• New generation DAC's and ultra low noise balanced current to voltage converter yields more musical performance compared to the m902
• Mono mode for checking mix phase issues (or listening to Pet Sounds)
• s-Lock™ phase lock loop sample clock regeneration for ultra-low jitter and rock solid digital stability
• High-current transimpedance headphone amplifier circuitry built to effortlessly drive low impedance headphones
• Balanced and unbalanced variable level analog line outputs
• Improved power supply architecture isolates headphone power amplifiers, line amplifiers, DAC's and digital logic
• Precision level control with a 99.5dB range in 0.5 dB steps
• Channel level matching accuracy of 0.05dB
• Improved x-feed circuit eliminates perceived loss of low frequency content
• Optional infrared remote control available
• Internal linear power supply with custom wound toroidal transformer
• Sealed gold contact relays used for all signal switching
• Five year transferable warranty on parts and labor

Updated Specs from m903_manual_RevA.pdf

SPECIFICATIONS ANALOG IN

Gain – Balanced Input

Headphone output, volume at maximum 0dB

Balanced Line output, volume at maximum +4dB

Unbalanced Line output, volume at maximum -8dB

Frequency Response – Unbalanced In > Unbalanced Out

@ 0dBu out +/- .25dB 27Hz – 54kHz

@ 0dBu out +/- .5dB 18Hz – 80kHz

@ 0dBu out +/-3dB 6.5Hz – 226kHz

Maximum Input Level

Balanced Input +22dBu

Unbalanced Input +16dBu

Maximum Output Level

Unbalanced output @1kHz, 100k Ohm load +21.5dBu

Balanced output @1kHz, 100k Ohm load +27dBu

Headphone output @1kHz, 50 Ohm load +20dBu

Impedance

Balanced Input 106K Ohms

Unbalanced Input 53K Ohms

Balanced Output 95 Ohms

Unbalanced Output 47.5 Ohms

Headphone Output 1.2 Ohm

Dynamic Range

@ 0dB gain, Balanced In > Balanced Out 117dB

@ 0dB gain, Balanced In > Headphone Out 116dB

THD+N Balanced Input

Headphone Out @ +10dBu, 50 Ohm load, SMPTE 4:1 <0.020%

Headphone Out @ +10dBu, 50 Ohm load <0.0060%

Unbalanced Line Out @ +10dBu, 100k Ohm load <0.00026%

Balanced Line Out @ +20dBu, 100k Ohm load <0.00036%

Attenuator

Channel matching <0.05dB

Attenuator Range 97.5dB

Output Noise Floor, Balanced Input

Balanced Output, volume at maximum, 22-22kHz -90dBu

Balanced Output, volume at minimum, 22-22kHz -103dBu

Unbalanced Output, volume at maximum, 22-22kHz -101dBu

Unbalanced Output, volume at maximum, 22-22kHz -105dBu

SPECIFICATIONS D/A CONVERTER

Input Sample Rate 32, 44.1, 48, 88.2, 96, 176.4, 192kHz

THD+N

44.1kHz, 24bit, 1kHz, -1dBFS, Unbalanced Out @ +15dBu <0.0009%

44.1kHz, 24bit, 1kHz, -1dBFS, Balanced Out @ +15dBu <0.0006%

Output level

Unbalanced Output @ 0dBFS, Volume at maximum, trim at 0 +9dBu

Blanced Output @ 0dBFS, Volume at maximum, trim at 0 +21dBu

Power Requirements

120VAC 0.16A

230VAC 0.08A

DIMENSIONS AND WEIGHT

Dimensions H1.7” x W8.5” x D8.25”

Weight 5 lbs (2.2kg)

Pre-order at 1795$ at rmcaudiodirect, I suppose it's close to the MSRP.

So as far as USB pro DAC/Headphon monitors, we now have:

Grace m902/3

Benchmark DAC1 ./USB/Pre/HDR

Lavry DA11

Antelope Audio Zodiac +

Am I forgetting anything?

Nah, I just edited the post afterwards.

I mentionned pro gear; as I understand, Burson, Meier, Luxman, Red Wine are targeted towards the audiophile market rather than the pro one.

Even Violectric is the "audiophile" division of Lake People, besides, the Vxxx series is more a headphone amp with USB DAC added while the example in the post above are more DAC first, headamp second.

I could add the Mytek Stereo 192 DSD DAC, but it was supposed to be out by Q1 2010 and is still in the works.

No idea, the specs are very close to the m902, same chip but slightly different implementation, who knows?

How's the Mytek 8x192 compared to its usual contenders, ie. Lavry, Apogee...

And How's the service? it seems to be a smaller company compared to the others.
 

Quote:

Originally Posted by charlienyc 

that's funny, i was about to add that immediately after looking at your original list.  i kinda feel obligated, since i run a Mytek 8x192 for pro work.