If you are asking what I think you are asking, it is the processor that is the primary difference. WAY faster on the V5.
Headphones: Koss Portapros, Sennheiser Hd435, Sony XB 500, Sony V150, Sony Street style, Roxy JBL's, Toxic Rock HR, Spirit Rocks HR, Coby crap.
Earbuds: Sennheiser Sporties, Sony EX57-LP, Beta Brainwavz x2 ( Lost one set), Coby crap, PL35's, Skullcandy inlines, Clip on HR, Cube IEMs, Apple, RIP Alphas x2, tinny toms x3
Players: RIP OS-72, Sansa Clip, RIP Sansa E320, Cube H880FHDR, Cowon D2, Nanite 1, Shuffle.
Phone : LG Rumour 2, Moto W385.