External hard drives and sound quality


I've just about filled up the internal hard drive on my Macbook with music files and am now looking at external hard drive options. Was wondering whether folks report any difference in sound quality when playing files from an external drive versus the internal?

I'm especially interested in hearing people's experiences using wireless hard drives. An Apple rep told me it would be no problem, as the hard drive wouldn't directly interface with the USB output, but I of course always like to be skeptical of anything an Apple rep says.
coverto
Blindjim,

Hmm, do you notice deterioration in your digital photos, video or other files stored as well or only with audio files?
mapman...same files, same dac cables etc. the only change was moving them from my laptop to nas. weird huh? my system is very revealing and i am certain of the difference. glad it's for the better!

things that should not make a difference sometimes do. i recently switched digital cables (to an mit oracle ma-x) from my transporter to berkeley alpha dac and it is the biggest change i have ever experienced in my system. that cable is spooky, very spooky. sorry to get of topic...
SSD's, that support trim and garbage collection, are pretty much plug and play with Windows 7. I've installed SSD's in all my laptops and desk tops. Music is stilled stored on conventional HD's (all 2.5"). With the older SSD's, and older OS's, it was a bit of a PITA setting up offsets, OS specific block lengths, and doing manual trim and garbage collection.
FYI - I just picked up an Airport Extreme and a Glyph GT050Q 1T drive, if that means anything to anybody out there... Will report back on the sound when I get everything hooked up, and thanks again!
I should add that an audio/video specialist at the store where I bought the stuff said he had never heard of somebody streaming music from an external hard drive to a Macbook wirelessly! Am I pioneering with this or what?