bflat
Headphoneus Supremus
I beg to differ, it is very annoying to me. My Oppo HA-2 handles switching very smoothly, so a solution is possible. (apples and oranges?)
The "solution" is generally to add a muting relay in the audio path. While I think Fiio's decision to not add this was a financial one, hardcore audiophiles will tell you to minimize circuitry in the audio path. Neither my SU-1 DDC or Holo Spring DAC mutes the clock switching and I'm pretty sure their decision was not a financial one.
Since you are using a music player that changes sampling rates on the fly, you might want to try the software muting option in your player. I know Audirvana has an option to add 0.5 sec or more software muting when a change in sampling rate is detected.