Then let it know if it’s sending its output signal to a system or to some headphones. Then turn it on, choose an appropriate volume level, and you’re up and running. That the FiiO K7 gets far ...
The R7 has a wealth of input and output options and FiiO says the R7 has been designed to work with a wide range of devices, including wired headphones, wireless headphones, active speakers and PCs.