Audiophilepure

https://headfonics.com/2020/01/fiio-k5-pro-review/

“You may not notice the upgrade on the outside, but this is a great feature that allows much more precise low-volume control, letting you enjoy sensitive IEMs in a quiet environment also to use the K5 Pro as a volume controller/ Preamp for powerful power amps.

Channel balance issues have always been a nightmare for mid-night listens especially with multi-ba IEMs and sometimes it may get too loud before you find the sweet spot/ minimum vol. that works, if you have very sensitive ears this may be a great feature.”