I cannot get my headphones to produce any sound and I do not know what to do.
I installed the required driver for the Topping D10, I connected the O2 and the D10 using RCA cables and I plugged in the USB of the D10. I power the O2 using a European adapter with the same specs as delivered with the device (red light burning when plugged in, also tried with other adapter). The volume in the toolbar has recognized the Topping D10, and the D10 also changes the displayed sample rate depending on the song played.
What do I have to do to get my headphones working?