I have just switched from Android to iPhone and gave my new iPhone 11 Pro Max a try with Oppo HA-2 SE paired with PM-3. Connected using Oppo's supplied USB to lightening cable, everything works fine. But, the iPhone volume rocker change the volume. This is something I can't understand. Considering connection using lightening-USB is digital the signal is supposed to bypass iPhone's DAC and go straight forward to HA-2 SE for decoding and amplification. If so how can iPhone control change the volume? Or am I missing something here, is it just a headphones output where iPhones DAC and amplifier is used?
Used Spotify for playback.
https://www.whathifi.com/oppo/ha-2-se/review
Used Spotify for playback.
https://www.whathifi.com/oppo/ha-2-se/review