Oppo HA-2 - Manual (Page 6)

Bottom:
4. Source Selector: Select one of the three input sources:
USB A port, USB micro-B port, or Audio-in.
5. USB A Port: For connecting to an iPod, iPhone or
iPad; or for charging a mobile device when using the
power bank function.
6. USB micro-B Port: For connecting to a PC, Mac, or
smartphone with USB OTG feature. This port is also
used for charging the HA-2’s internal battery.
Side:
7. Power Bank Indicator: A blue light indicates that the
HA-2 is supplying power to a connected device via the
USB A port.
8. Battery Level / Charging Indicators: Four green lights
indicate the HA-2’s internal battery level. When
charging, these lights also indicate the charging status
and currently charged capacity.
9. Battery Check / Power Bank Button: A single press of
this button lights up the Battery Level Indicators to
show the HA-2’s internal battery level. Press and hold
this button to turn on/off the power bank function, as
indicated by the Power Bank Indicator.
10. Bass Boost Switch: Allows you to enable the Bass
Boost feature. A visible green bar means Bass Boost is
enabled.
11. Gain Switch:Allows you to select low (L) or high (H)
gain for the headphone output.