jujueye

...and some head scratching from MikeSty...haha....

OK, first off, no data is added back in. You are correct.

Upsampling just takes the 44/16 data, and converts it to a higher rate format. I know it seems a little weird. (It is obviously not as good as sampling it at the 96/24 or whatever in the first place.) But this wasn't my idea...lol... A company called Elgar started doing it in their $10K cd players and DACs a few years back. Others followed (and not in an "if your friends jumped off a bridge" way either...lol) Often some extra bits are added in during the conversion, I believe. There's lots of information about it to read, but it still is a bit confusing.

Here is an article from Stereopile about diggin in to what it does and maybe why it sounds so good. Or just google it as always.

For home use, I have a copy of CoolEdit and can read and create files. One feature available is to "Convert Sample Type" which allows conversion from just about any data format to another. Sample rate (44100, 9600, etc) as well as resolution (8, 16, or 32 bits) can be selected as well.

So, all this to say: the iPod can handle 96/24 data, and sounds pretty damn good with it to boot. But I only use it on my really favorite or really good recordings.

PM me if I've made your head hurt!

Edit: BTW: I'm not so sure I could hear this with the stock iPod headphones. I did hear it with some Sennheiser HD600 headphones and a dedicated headphone amplifier. YMMV!