Just got the iBasso T4 this afternoon, so here are some pictures and a quick impression. Sorry boys and girls, no Xin here 
Quick Impression:
I was mainly comparing T4 to E5, which is my main on-the-go portable amp at the moment. The source is iriver clix2's headphone-out on 80% volume. Music of choice are various album ripped as >256kbps LAME mp3 or WMA. The earphone of choice is Head-Direct RE0.
In very rough and subjective term, I'll say E5 is about 70% of a T4. The main improvements are bigger soundstage, slightly better instruments separation, slightly better treble and better bass (fuller, warmer body) if you switch both to bass mode. In comparison, E5 sounds more mid centric while T4 is better on extending to both end.
Regarding hiss, I chose to use UM2 for the test. For E5, hiss is most noticeable in max volume, and decreases to none as the volume approaching minimum setting (about <1/4 of total). For T4 in low gain with lowest volume, a constant hiss is detected but the volume is very low, roughly the same as E5's hiss on 1/4 volume setting (which is when E5 just starts to hiss). For T4 in high gain with lowest volume, the level of hiss about about E5's hiss b/w 1/2~3/5 volume. The good news is, T4's hiss doesn't increase a lot even when the volume is turn to max. The increase of hiss b/w lowest and highest volume is perhaps less than 50% of that in lowest setting..
Quick Impression:
I was mainly comparing T4 to E5, which is my main on-the-go portable amp at the moment. The source is iriver clix2's headphone-out on 80% volume. Music of choice are various album ripped as >256kbps LAME mp3 or WMA. The earphone of choice is Head-Direct RE0.
In very rough and subjective term, I'll say E5 is about 70% of a T4. The main improvements are bigger soundstage, slightly better instruments separation, slightly better treble and better bass (fuller, warmer body) if you switch both to bass mode. In comparison, E5 sounds more mid centric while T4 is better on extending to both end.
Regarding hiss, I chose to use UM2 for the test. For E5, hiss is most noticeable in max volume, and decreases to none as the volume approaching minimum setting (about <1/4 of total). For T4 in low gain with lowest volume, a constant hiss is detected but the volume is very low, roughly the same as E5's hiss on 1/4 volume setting (which is when E5 just starts to hiss). For T4 in high gain with lowest volume, the level of hiss about about E5's hiss b/w 1/2~3/5 volume. The good news is, T4's hiss doesn't increase a lot even when the volume is turn to max. The increase of hiss b/w lowest and highest volume is perhaps less than 50% of that in lowest setting..
