[Duck-Sauce]

Hey,
 
In a review of tech power up, they said the RE0 need a portable amplifier. I am thinking at buying the RE0 because they are cheap. I am mainly listening to house, trance or rock and I was wondering how the amp could help the earphone to sound better. 
 
Thank you for your help

 

[kmhaynes]

The amp increases the power going to the RE0.  The RE0 needs more power than some earphones to sound good, to sound fuller.  
 
The E5 is a nice little amp that will give the RE0 a fair amount of additional power.  The next step up in power (staying under $100) would be something like the PA2V2 (not very portable), or a JDSLabs CMoy with Bass Boost (more portable).