I had two Vox headphone amps that sounded ok but all the plastic made them lacking in durability. So i got a PJB Big head and yep that mini usb socket broke away, i had it repaired but the tech told me it will soon come off again, he was right. If PJB had theirs made with a USB-C connector it would have lasted longer. Now i use my Stanley Clarke Acoustic preamp as a headphone amp. All the connectors are proper and it sounds great. Not cheap but it's a well made piece of kit.