This answer applies to R1 Mk3 R7 Mk1 / Mk2
The USB socket on the rear of R1 Mk3 and R7 Mk1/2 serves as a charge port so users can conveniently charge Smartphone’s etc. This is useful to maintain the charge of such devices when streaming music by Bluetooth. Its secondary function is that of a service port for diagnostic and software purposes.
If not, please do not hesitate to contact us via our support enquiry form.