This is from my private audiophile collection.  If you are looking at this, you probably know this is a CLASS A AMP.  The finest design to deliver audio, however ALL CLASS A amps run a bit hot in temperature.   This is USB to micro USB Look at my feedback and bid with confidence.   This Headphone amp was rarely used and is ideal for portable use or travel as well.  I will only ship to continental USA unless prior plans are made via email before auction ends.