[barzman]

hi, iv seen on ebay and other places selling westone 3's that they now provide a free amp along with the iem's themselves. i may sound really dumb here but what is the purpose of a headphone amp and is it worth getting?? 

 

[Zalithian]

In my opinion, most IEMS don't need an amp. Amps are generally used when a source doesn't supply sufficient power to the headphones. There are other reasons to use amps, but they are mainly for providing more power to headphones like the HD650 and other things with high impedance. Some earphones specifically don't have much bass, and a portable amp can add more bass and make the earphones sound more full. I guess impedance can alter the sound as well. I don't know a whole lot about electronics and impedance though.
 
Personally I don't think it's very helpful unless your source can't power the earphones well, or you are trying to get a slightly fuller sound.