[Uri Cohen]

My headphones are the Grado RS-1is and sadly while I like my MZ-R70 minidisc player the built-in amp is for me not good enough to drive the RS-1is so I need a portable headphone amp that can drive the RS-1is much better than the Minidisc player.  I don't know too much about portable amp but my budget is $100 at most for an amp.
 
Any ideas? 

 

[Mad Max]

E5/E7, Nuforce Icon, or PenguinAmp Caffeine, probably.
You might be able to find something good in the FS forums.

 

[Uri Cohen]

Alright, what about a portable amp that you can carry around with you and should be enough to power the Grados?  
 
I'm looking for an portable amp that can make the Grado very loud with good details.  The MD portables just not cutting it with driving the Grados.  I can spend a little more if it will improve the sound. 

 

[Uri Cohen]

Any ideas people?