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Grace 901 replacement: Grace m902 - Page 7

post #91 of 209
Headroom doesn't have it listed yet under Headphone Amps.
Maybe if someone rang them up, they'd have a (preliminary) price for you.

Is it shipping yet?
post #92 of 209
Quote:
Originally Posted by mbgrace
Not sure. The USB interface on the m902 is a Burr Brown PCM2902 which uses generic audio codec drivers in windows and mac. It is limited to 16bit/48kHz.
I have tested the interface to be bit accurate with windows 2000/xp
This is one very exciting information about the TI USB receivers for us diy guys

Thanks.
post #93 of 209
I'm not in the market for buying anything at the moment (need to pay bills and build up savings again), but the sheer versatility, convenience, and likely very good sound quality this new Grace product offers would put it near the top of my list if I was. Just thinking of combining this w/ a silent pc is making me very excited. This sounds like a really cool product and a big improvement over the 901, good job Michael.
post #94 of 209
Hi DukeTogo,

Retail price of the m902 will be $1695. We will be carrying them. You can e-mail me if you have any questions. jamey@headphone.com

Cheers,
Jamey
post #95 of 209
Jamey - Thanks for the update!

Does anyone have any more information about the "remote option" ?

Does this option add anything to the base unit, like firmware or hardware to support IR? Or is it just a remote control to hold in your hand (and the base unit already supports this feature).

Anyone know how much this option adds? Pictures?

I must say this is a _very_ exciting product.
post #96 of 209
Still a little curious. Did you make any test about the jitter of the pcm2902 ?
post #97 of 209
About the question that asked if the m902 could handle the output from "DVD-Video, SA-CD, DVD-Audio, and Red Book CD (along with HDCD or JVC xRCD)"

My feeling, and this is just an educated guess, is that the Grace units (901/902) will only be able to digitally decode the audio in some of those situations.

DVD-Video (well the digital audio stream)
- I think this is likely only going to work if you aren't outputting any fancy DTS/Dolby surround-sound, downmixing 5.1 --> 2.0 or something.

Generally I think one can forget about multi-channel audio - these DAC's are not designed to decode this stuff, presumably that requires additional hardware or licensing fees to be paid to Dolby Labs or whoever. Plus even if they could handle it, they don't have multi-channel outputs, so you'd just have to throw that data away. It would be nice if they could "pass-thru" the data say on to your high-end surround sound processor, but they don't seem to have a digital out. Some models do, but even then I doubt you'll find that they support that.

SA-CD (digital audio stream)
- assuming you can GET your SACD to output its contents digitally, without downgrading the bit-rate, I'm not sure that this would work. SACD doesn't use PCM encoding, but rather DSD (iirc)

DVD-Audio (digital audio stream)
- this should work, since DVD-A is just PCM-encoded but using higher bit-rates, and the Grace supports up to ... 192 in the m902. The m901 supports up to 96. I am not sure if there is a standard bit-rate for DVD_Audio, it seemed it was kind of up to whoever masters it.

Red-Book Audio CD
- yeah this should be fine, plain-jane CD audio right...

HDCD
- this would require some additional firmware or decoder hardware, and I doubt that this would be supported by the Grace or any DAC that does not explicitly make that claim. I think Microsoft now owns this code/algorithm anyway, they bought the company that previously held the patent on it, iirc.

xRCD
- wow I must have missed that one ... never heard of it. If it requires any similar decoding like HDCD, probably not supported.


Anyway, this is just my theorizing, if someone else knows better then feel free to correct me. I'd love to find out that some of the stuff above IS supported. :-)
post #98 of 209
Quote:
xRCD
- wow I must have missed that one ... never heard of it. If it requires any similar decoding like HDCD, probably not supported.
xRCD's are Red-Book Audio CD's. What makes them special is the extreme care the sound engineers take in mastering the cd. (For instance, an atomic clock is used as a clock generator to help reduce jitter.)
post #99 of 209
Quote:
Originally Posted by DukeTogo
Jamey - Thanks for the update!

Does anyone have any more information about the "remote option" ?

Does this option add anything to the base unit, like firmware or hardware to support IR? Or is it just a remote control to hold in your hand (and the base unit already supports this feature).

Anyone know how much this option adds? Pictures?

I must say this is a _very_ exciting product.
Hi,
I don't have pictures of the remote at the moment but it looks remarkably like the one in the picture here: http://www.jeffrowland.com/conpix.htm
It is a simple IR remote that allows access to all of the features in the m902:
-Volume up/down
-Line/Phones switching
-channel balance
-cross feed on/off
-mute (this is a bonus feature not available at the front panel of the m902)
-front panel led dimming
It is not super cheap but they are not made in the same quantities as the ones you find at radio shack. Also, since there are no "extra" buttons it is easy to operate in the dark once you memorize which button is which.
Oh, the IR receiver is built into the unit so there is nothing else needed.

Some other things I can tell you about this unit are:

Dimensions w8.5" x d8.25" x h1.7" not including connector, knob and foot protrusion. The depth is 9.4" including knobs and connectors. Height is 2.1" with the feet on. By the way, the feet are removable and we will eventually have some tip toes that will screw into the foot mounting holes.

Cross Feed: We have licensed the Meier Natural Cross Feed Filter. It is set to a level about equivalent to Meier's "low" setting. It is not adjustable. The Meier circuit is incredibly elegant in its simplicity which allows it to present a nice sound stage with an absolute minimum loss of signally fidelity. It is not an aggressive model of the HRTF but it is very musical sounding.

There is no HDCD, DTS or Dolby Digital decoder in the m902. In fact, there is no dsp processing at all outside of the digital filters in the D/A converters.

Cheers,
Michael
post #100 of 209
Thanks for replying. I might be interested in the new grace. But have some questions. The volume control puts out noise when you alter it. Also it is difficult to fine tune the volume. Have these problems been ironed out or will you just use the existing grace 901 output stage in the newcoming one? Thanks
post #101 of 209
Quote:
Originally Posted by GoRedwings19
Thanks for replying. I might be interested in the new grace. But have some questions. The volume control puts outnoise when you alter it. Also it is difficult to fine tune the volume. Have these problems been ironed out or will you just use the existing grace 901 output stage in the newcoming one? Thanks
The volume control in the 901 should not be noisy. If it is I would like to get it back to the factory and look at it. Give us a call (ask for Jamie) 303-443-7454 and we can arrange this. The matter of fine tuning the volume can be problematic with the 901, especially if you are using very efficient phones. In this case volume settings might be in the 7:00 o'clock to 11:00 o'clock position were the level steps are large (4, 6 and 10dB). We can lower the gain of the amplifier in a 901 to help correct this problem but it will limit the maximum level you can get out of it for ineficient phones that need lots of power. The level control in the m902 has very fine .5dB steps with a 99dB range (that's 198 volume settings!). This allows the m902 to work with a wide range of headphone sensitivities.
I hope this answers your question.
Michael
post #102 of 209
No another headfier brought this issue up while doing the review for headfi of the grace 901. When will it be possible to pre-order the new grace?
post #103 of 209
Quote:
Originally Posted by GoRedwings19
No another headfier brought this issue up while doing the review for headfi of the grace 901. When will it be possible to pre-order the new grace?
We will be shipping m902 latter this month. I would imagine that you could pre order one now.
Cheers,
Michael
post #104 of 209
awwwwww nooooooooo here comes the trigger finger.
post #105 of 209
Oh sure, like YOU need more toys!!

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