Paul Hynes/Steve Nugent design 5V USB Linear Power Supply.  This is a new item.
LPS can handle up to 4 A but has a 3 A fuse.  

Best of both worlds.  Having owned the entire Empirical Audio product line throughout the years, his power supplies have a high current reserve for rapid demand and optimal performance.    

The upper USB port is signal in and the lower USB port with cable is signal out.

$900 new, $650 shipped worldwide, PayPal, or bank transfer.