I am having trouble deciding which headphones to get. I had the M50's but i returned them due to their bulkiness and making my ears feel hot and uncomfortable after a short time. I wasnt amazed with their sound quality but I didn't have an amp. I am going to get an amp probably, but I was just wondering if any of these headphones would sound good without an amp? Do any of these need an amp to sound good? Whats everyones imput on any of these headphones? Any imput would be greatly appreciated! Thanks!