I use my X5 with E12DIY (opamp cannot remember) to drive HD800 at nite..... you audio snobs can crucify me.. LoL
I also got a DHC OCC DIY cable for the HD800 to make them more friendly to move around....
The fast and tight bass of X5 did a get a while to get used to... but this X5 really nailed it good...neutral, transparent, good detail, well controlled frequencies, not dark sounding... The serious complaint I have for X5 is that........................ it did not release soon enough otherwise I probably would not buy other DAPs....(Disclaimer: HM901 still can portray thicker and better texture sound than X5)
It is really impressive how much mature the X5 product is when comparing to X3. The X5 SQ is much better than my X3 mod (8741 + AD8620)... the price difference between X5 and X3 is really worth it...(I did spend silly amount of money to mod the X3..
)
If my on order CIEM has good synergy with X5, I will probably not spend money on portable gear for the rest of the year..
(and use the money to buy a small Class D speaker amp to drive my HE-6 in my room, suggestions are welcome... EF6 is too big for my small room)
I have a hard time imagining what X7 will sound like... must be epic considering it will be the statement piece..