KHV:
no distortion, discoloration ... noise imperceptible. No drain and appreciation of sound!
only useful for traveling in connection with an MP3 player / iPod / iPhone because level is significantly increased (more than enough).
For PC / Laptop not notwengig because laptop is unpleasantly loud at 80% volume.
DAC:
I'm not sure if you need it, because the performance is mediocre (therefore not the interfaces as Toslink and Coax useful).
I have to take to make the decision about 5 hours sitting. The following results came out:
Configuration and rankings:
1 (100%) Onkyo TX-NR3009 (KH-output)
2. (90%) Asus Laptop + FiiO E17 via USB (DAC)
3. (85%) Asus onboard sound card
4 (80%) IPod + FiiO E17 (KHV)
5. (80%) IPod
In parentheses: the subjective assessment of sound, which I have Onkyo set with 100% as a reference.
Conclusion:
The device is versatile, unfortunately with average sound quality. Reiner headphone amplifier can be found at FiiO for little money (FiiO E11).
As DAC I would not recommend it, there are better devices such as Asus Xonar Essence One or Teac UD-H01 - both not portable but are even better than Onkyo.
