Music from hard drive better than CD?

My guess is music coming off the hard drive looses it timing?

As I understand it, this is the advantage of using a USB DAC (I think the DigiDesign unit is just a processor that upsamples(?) and sends the digital feed to the DAC - much like a soundcard).

Since USB is bidirectional, using a USB DAC with a direct USB connection to the HD allows timing errors to be addressed both at the HD and at the DAC. Using optical, or S/PDIF output to the DAC you are limited as these are both unidirectional feeds. I don't know much about the Digidesign unit, but just looking at the specs it would occur to me that is using the USB for power, but I'm not getting how it is providing 24-bit S/PDIF output unless it is upsampling. Standard USB is only capable of passing 16-bit data. USB 2.0 may pass more. Check out the basic information on the Wavelength Website. You may contact Gordon Rankin via that site and inquire further. I just notice that the specs on the DigiDesign unit says "100% USB Powered"....does that mean it is passing information as well, or are you getting your digital output elsewhere?

I believe you on the timing errors making or breaking the reproduction of music.

Marco

Nickway - If timing errors occur it would be on the digital output. I'm not familiar with the apple OS. Does apple OS have mixer issues like WinXP? Is there something in the apple OS that would approximate kernel streaming or ASIO in WinXP. When I first went to a DigAudPC the increase in dynamic range was fantastic.

Hi Guys,

To answer some of your questions. The Mbox, takes its power over the USB cable as well as passing the information via it. I used the SPDIF digital out on the mbox to go to my Wadia.

On the laptop we set everything up for the best sound quality as recommended by Steve Nugget of Empirical Audio in his posts.

What it sounded like was the timing of the music was destroyed when coming off the hard drive. There was nothing else on the laptop running when we were doing this. We even turned off the screen to help keep noise down. We tried different file formats and nothing seemed to help.

When we tried to listed to the same disc playing in the CD drive it sounded better. It did not have the all of the virtues (dynamics, staging, etc..) of the harddrive, but it did have timing (although not that great).
But what good is everything else if the music is lacking timing?

So the fact that it sounded better of the CD drive then the HD makes me believe their was nothing wrong with the Mbox. It makes me think that music coming off the HD itself is the problem. Like I said, everything (and I mean everything, detail, depth etc...) was better when coming off the HD, BUT the timing was nowhere to be found. If the timing could be made right I would be a believer. Like I said, I really wanted it to work. I guess the old saying is right: There is no free lunch.

Have you guys ever personally tried doing this? If so what were your results?
Please tell me I am wrong, as I would really like to be. However somehow I doubt the timing issues will be fixed anytime soon.

Cheers,
Nick

Nick - Did you reference the Wavelength link I provided? Here's some info from that link:

Basically the DAC has a single digital USB input. USB unlike SPDIF is bidirectional and therefore has error correction and buffering on both sides. This happens automatically so the data on the disk is identical to what is going out all the time. Also since this interface is asynchronous the clocking problems associated with SPDIF go away. What happens is... On power up of the computer the 2 devices negotiate services. In this case the Cosecant tells the computer it can do 16 bit audio at 32K, 44.1K and 48K. Since the USB receiver only has to handle these 3 frequencies, the clocking to the separate DAC IC has almost no jitter. SPDIF actually has to be synched to the exact frequency of the transport (i.e. if the transport is working at say 44.0896K instead of 44.1K the dac has to sync to that frequency). Therefore the jitter problems of SPDIF almost go away using USB. So using USB we have a zero error protocol to link the computer to the DAC and very low jitter what else..... The Cosecant is platform independent also OS independent. Any computer that has USB output will be able to hook up to the Cosecant without software drivers. Just select the Cosecant for Audio Output in your system preferences or control panel and your done.

I believe your Digitech is acting as an upsampling soundcard. Regardless of upsampling it is processign the data from the HD and sending it on to the DAC via S/PDIF (unidirectional). My guess is that the 'compromise' lies in the Digitech.

Marco

...furthermore, you may also want to reference this page for optimum setup for Mac and see if the information corresponds to what you've been using.

Marco