All the recent iPod models I have tried.....Classic, 4th-gen Touch, and 4th-gen Shuffle.... all sounded the same to me with no EQ enabled and using the headphone-out. The older models with the different chips inside sound a little different, which some people prefer and some do not.
take a look here
That just talks about what I mentioned....some people prefer the older ones, and some don't. This article is usually posted by the Wolfson lovers, because the writer of the article prefers the Wolfson sound. But the fact remains, it is a matter of opinion....and there are many who prefer the Cirrus sound too. I am definitely in the Cirrus camp.
Edited by Achmedisdead - 11/8/12 at 3:11pm