Custom order options:
1, Custom order two pair RCA outputs，replace
USD5 without shipping delay .
2, Upgrade TCXO for the ES9028
Cost is USD20 without shipping delay .The
upgrade had slightly improved the sound transparency .
3, Custom order HDMI replace RJ45 I2S
Price is USD20, without shipping delay.
Upgrade USB isolator price is USD32.
USB isolator can avoid the computer electric interrupt feed in the
DAC cause the sound quality worse . In AB compare , it can
improve on sound transparency slightly .
After USB isolator upgrade, the USB spend the USB power supply, and
can not support phones because the power limit of the phones .