While my main sources are vinyl, Redbook CD and FM, I also have a computer hooked up to my system to stream radio stations off the Internet at speeds from 64k to 320k. When I added a tube preamp all sources were improved greatly, but the biggest improvement was with the streaming. My theory is that tubes add back some of the harmonics lost during the MP3 compression process. Regardless of how/why it works, it makes streamed music very listenable.
I say hook up the iPod and enjoy!
I say hook up the iPod and enjoy!