Originally Posted by eduardo1969
Correct me if i am wrong ,but i only need a amp if i hear a hiss on my p5 ?
Or are there other benefits when using a amp like fiio e12 and the imbasso?
If my opinion on the matter isn't already clear, buying an amplifier to get rid of another amplifier's hiss is throwing good money after bad. The problem isn't the amplifier; it's the headphones. Replace the headphones with something less sensitive and the hissing problem should go away. Here are a couple of tips: sensitivity and impedance do not correlate with sound quality. Neither does price.
As a sort of quick and dirty guide, if you find yourself asking if you need an outboard amplifier then you probably don't need one. Conversely, if you know you need one then you wouldn't be asking, although you might ask for suggestions about which amplifier provides specific functions and features that you want. The purpose of an amplifier is, as the name indicates, to amplify a signal. That is to say, more power. DX50 delivers more than enough power to drive nearly any headphone up to around 300 ohms nominal impedance to deafening volume levels. Some calculations on that point that I did a few weeks back:http://www.head-fi.org/t/679473/the-ibasso-dx50-thread-latest-firmware-1-2-8/10275#post_10172331
Fiio E12 is considered to be inferior to DX50's amplifier. It doesn't sound as good.
Another tip: there is no "best"; there's only what sounds best to you. Don't be afraid to step up the headphone jack gain. Increasing the gain and reducing the master volume appears to lower the amplifier's noise floor. If it solves any noise problems for a given set of headphones you use then that's best for those headphones and your ears.