Fiio K9 Pro ESS review: An outstanding high-end desktop DAC/amp

The Fiio K9 Pro ESS is a phenomenal desktop DAC/amp that nails the sound quality. It has all the connectivity options you could ask for — including Bluetooth 5.0 — and the clean sound signature makes the DAC absolutely shine.

source https://www.androidcentral.com/accessories/audio/fiio-k9-pro-ess-review