Newbie Setup Question - Digital

I would expect the software driver used with a particular USB device could make a difference in sound.

I 've heard others indicate that different USB cables make a difference as well, but I have difficulty understanding how different digital cables can make a difference.

I've never known USB or other common computer interface cables, when used within proper tolerances, to drop or alter bits in other applications. What makes audio special enough to hear a difference?

BTW I have no difficulty hearing differences in different analog cables (as opposed to digital) and understanding why these can sound different as well.

I suspect differences in USB cables is purely force of suggestion.

Mapman I think the way what you said about drivers is correct. I was reading something the other day about how the drivers built into Vista/XP are insufficient in some way. I think some of these devices coming out must inject a custom driver into the operating system when connected that instruct the computer how to behave.

As for different cables, I forgot to mention that if you look at the Wavelength Audio homepage, and look at their discussion of computer front ends and what to buy, they seem to assume that electrical/computer noise from things like computer fans and hard drives does not make it across USB into the system. Thus it shouldn't really matter what kind of device you use to serve the DAC--whether it is a silent device with a solid state hard drive, passive cooling or whatnot. Even if you had a video card with a fan that blows like a hairdryer, I don't think it "pollutes" the USB signal the way it does with SPDIF/COAX.
I fail to see how the actual computer and motherboard used does not impact the sound while a USB cable can?

The difference I think has to do with the way USB data is "packetized." I think if a single bit is out of place the entire packet gets flushed. Things get transferred in chunks and not a continuous stream. I was sort of under the impression is that one of the big selling points of USB is that it should do away with the need for expensive S/PDIF digital cables.

I suppose it is possible that it makes a difference but I find it hard to believe because of the computer networking origins of USB.

Sorry.

I just learned the the DAC Magic is pc only - not mac compatible.

Marty