use volumio-es9018k2m-plugin-0.1.0-sys-2.3x.zip when Volumio version is less than 2.411
use volumio-es9018k2m-plugin-0.1.0-sys-2.4x.zip when Volumio version is more than 2.411
- es9018k2m chip control by i2c
- volume, mute control
- adjust balance and left/right channel switch
- digital filter(Fast/Slow rolloff), IIR, de-emphasis filter
- i2s/DSD DPLL(Digital Phase Locked Loop) Jitter Reduction