My cd player has a USB input on its face that lets me plug in any drive that has a USB out, and listen to music files using the player's DAC (Cirrus Logic CS4398). It plays every major file format except FLAC.
I've been using it with my Ipods a lot. I rip all of my music into ALAC lossless format; I've got a couple of big Ipod Classics (160GB/80GB), with a lot of my stuff on it. It's extremely convenient - no messing with cds and cases (some of the newer paper ones are very nice and conscientious, but they're not exactly durable). It also sounds great - I think cds sound a bit better, just a touch darker, but I love just plugging the pods in, scrolling and pushing Play.
I know there are better players out there, but I really love this feature, and I don't see any superior players with this feature. And I'd like to put off getting a separate DAC or Ipod dock for as long as I can ($$$, among other things). So, rather than get a DAC and/or upgrade my cdp, I'd like to get as much SQ as I can out of this player, without spending so much that I might as well have upgraded (and gotten a separate DAC/dock).
So once I got the player, and got used to using the USB input, I started looking at aftermarket Ipod cables. Like a lot of people, I'm interested in aftermarket stuff that improves SQ, or is supposed to. I know that cables and cords are a source of controversy in the listeners' community. If something doesn't cost too much, I can afford to try it out, so I can at least tell myself I heard it (or didn't) myself.
Most people are using these cables to go computer-to-DAC, and using other connectors - USB-to-firewire, USB-to-mini-USB, etc. So I didn't find many reviews of Ipod USB cables (in fact, I found none). Also, reviews and forum discussions of USB cables indicated that you have to spend $100+ to get a noticeable improvement over any stock cable.
Like I said, I know these are controversial subjects. I don't know enough to tell anyone why a USB cable could make a difference in SQ, and I don't know enough to say why it couldn't (besides "it's just numbers"). But I did have some cash laying around, so I picked up an AudioQuest Carbon Ipod USB cable. It's just a little over $100 - not Audioquest's cheapest USB cable, and not their most expensive - and other versions (e.g. firewire) have gotten some good reviews and comments.
I wanted to post my impressions, if only to get the ball rolling on a discussion of these cables, because there's not much about them out there yet. I was going to wait a bit before posting, though; among other things, these cords supposedly have a burn-in period (another controversial topic, I know).
The thing is...as soon as I plugged this cable into player and pod, and did a crude A/B with a track that I had just listened to on stock (Steely Dan's "Rose Darling"), I noticed a difference - a good one. I've been listening for a few hours now, doing A/Bs here and there. As of now, I'd say it's half-way between stock cable and cd; space between tracks is clearer (darker?); things sound a bit tighter, including bass. Also, the soundstage seems slightly improved - some stuff seems a little further out front, and some sounds a little further back, in terms of imaging. There's also a bit less of that slight distortion at the tip of some mid/treb tracks that I think we call "grain". More of a presence at lower volumes, as well. And, yes, I think I can hear things I haven't heard before, at least through the Ipod USB.
Is it all in my head? It may be. I don't discount the possibility; however, if it is, it's one of the less subtle improvements that I've imagined. Not amazing; just better.
I only have two concerns, so far. The first is that, while I think I can hear more, trebs may be a little flattened. I might call it "veiled", but I don't want to overstate it. Maybe burn-in will change that. Also,the plastic casing surrounding the USB connector seems a little loose. Connector connects fine, plastic just seems loose. Not necessarily more than stock, though. I've seen someone else noticing this, so it may be an issue, or I may have been oversensitized to that factor, or both. It wasn't the most expensive model, but it wasn't cheap. So we'll see.
I guess I need a little more time, and things may get better (or worse) after burn-in. I'd love to hear about anyone else's experience with USB-to-whatever cables. In any case, I'll be back with updates. More later.
btw I have no affiliation or relationship w/ Audioquest! Or Marantz. Or Parasound etc.