Some flaws of K5 Pro (JMHO)
1) Weird sizzling/humming sounds that are audible when nothing plays ... both on my LP6s and any IEMs I use. I have not noticed anyone else stating that anywhere online/this forum so it could me my set-up. None of the noise happens in my evergreen Fiio E10.
2) The volume increase from 0 to anything audible is not gradual/smooth. After switching it on … it just starts out a little louder than ideal. Sometimes at night the "minimum volume” is too loud and there is no way to control the volume from PC.
3) Both the front and rear ports are always on. I have to turn off speakers if I want to use the headphone jack or else both play together: This can be a real big one for many.
Overall I love it. It has been compared to JDS Atom
Just a note: In my country iFi Zen DAC was available a bit later after I purchased. iFi Zen DAC is cheaper than K5 Pro and has balanced outs + USB3.
EDIT: Just when I was thinking "I should have bought the zen" I found this:
https://www.audiosciencereview.com/...ds/ifi-zen-dac-and-headphone-amp-review.9885/
K5 Pro FTW!