1. Is the K1 for use with smartphones?

A: The K1 was designed as a USB DAC for computers, and not guaranteed to work with smartphones.  It also does not come with OTG cables for connection with smartphones; users would have to buy these separately.  iPhone users need the Camera Connect Kit and not a regular Lightning-USB adapter cable.

The K1 has no battery and draws power from its connected device, which means it would draw power from a connected smartphone.