Grace m902 USB input
May 3, 2008 at 1:03 AM Thread Starter Post #1 of 14
vpivinylspinner

vpivinylspinner

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I have a 902 on the way to me to use in my office for my first computer as a source system. I know that the USB input only allows for 16 bit and 44/48 mhz while all other digital inputs can upsample to 24/192.

Am I going to have to get some kind of usb sound card for my work laptop to get good sound out of the Grace?

Does anyone use the Grace with USB that can tell me about sound quality?
 
May 3, 2008 at 3:36 AM Post #3 of 14
In my recent experience with the M902 and a couple of other DACs, the big advantage of switching to optical is that I don't have the hiccups and glitches that I experienced with USB in Windows XP, when connected to the Grace and several other DACs (Monica II, Benchmark USB, etc., etc.). I suppose now that I've switched to a Macbook Pro (I live in Windows via VMWare Fusion for work; use MacOS for iTunes), it would be interesting to compare the two connections, but that will have to wait for a very slow day.

I'll add that the Grace is just a fantastic headphone amp; five stars in every regard. I've been experimenting with some other DACs (Monica II USB with Hagerman Bugle and other power supplies; Lavry DA10; Headroom Ultra Micro DAC; etc.). The other DACs have different and interesting sound signatures, some perhaps even prefereable in some aspects to the Grace (except the Monica, which as I've built it isn't in the same league, though a damn fine DAC for less than a tenth of the price). I may need to sell one of these DACs, but it will not be the Grace: Rock-solid DAC and amp and incredibly flexible in and out.
 
May 3, 2008 at 5:06 AM Post #5 of 14
Hey cconnaker, I understand that there's nothing in theory wrong with USB. It's just that in practice I could never get rid of the noise on an x86-based laptop running XP, no matter what I tried. Thus my point about the practical improvement of switching to a platform that supports bit-perfect output on an optical port...
 
May 3, 2008 at 5:17 AM Post #6 of 14
CDs are 16bit 44.1 so the answer is a resounding no. You can try upsampling from the coax or optical output from your computer and it may sound different but I don't really see how it is really worth all that. You computer doesnt have coax or optical built-in?
 
May 3, 2008 at 5:21 AM Post #7 of 14
Quote:

Originally Posted by royewest /img/forum/go_quote.gif
Hey cconnaker, I understand that there's nothing in theory wrong with USB. It's just that in practice I could never get rid of the noise on an x86-based laptop running XP, no matter what I tried. Thus my point about the practical improvement of switching to a platform that supports bit-perfect output on an optical port...


Usb ports com in pairs. The DAC must be plugged into a port with the adjacent port empty and you cannot use a hub. Noise problem eliminated. If not then something is not functioning properly or you have a computer that is junk or has some junky components.
 
May 3, 2008 at 5:25 AM Post #8 of 14
Hm. I worked pretty hard at eliminating the noise from my Thinkpad T60 running XP and iTunes. It is remotely possible I did not try the configuration you recommend (solo port and no hub), but very unlikely. I had the same problem with numerous other machines running XP and communicating with a DAC over USB. I discussed this on several posts at the time. I gather that others have not experienced this problem; however, several folks have and have sought advice on this and on other forums. Perhaps I was just unlucky -- I'm only recounting my personal experience.
 
May 3, 2008 at 6:13 AM Post #9 of 14
I had this problem and I was reading a Musical Fidelity manual one day and they made no bones about the fact it must have its own ports (usb header) and was not to be used on a hub. I tried it and the problem was solved. I was crushed when I realized my Dac had some noise interference and I read that manual a couple of days later and I was so relieved. Give it a try.
 
May 3, 2008 at 3:17 PM Post #10 of 14
Thanks for the tip, GordonFreeman. I believe the "noise" was not EMI but the digital stream not keeping up on the USB bus when there was the least load on the PC -- I'll add that the T60 had a dual-core processor and loads of RAM and the load was not exceptional. But I will experiment and report back -- I would certainly be delighted to discover there was something I didn't try that works for iTunes on a PC.
 
May 3, 2008 at 3:26 PM Post #11 of 14
Apologies to the original poster for somewhat hijacking this thread: I agree with ccnonaker: Just plug it in by USB and enjoy; the sound from lossless audio files is superb.
 
May 3, 2008 at 6:00 PM Post #12 of 14
No need to apologize, this information could come in handy when I put this system together next week.

Thanks for the tips everyone.
 
May 5, 2008 at 11:26 PM Post #13 of 14
Well I hooked the Grace up via USB today at the office. Sounded pretty good though I just had my Shure se530s to plug into it today. I also noticed that the back of my docking station has S/PDIF connection so I am going to bring a digital cable and some headphones with me to the office Wednesday and really try it out.
 
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