I haven't used the USB input, but according to the manual it does support external hard drives and flash drives. Just be aware that if you use that method you'll only be able to see folder names and file names, with no other information about the recordings. I think navigating through a terabyte of folder and file names using the screen and controls on the front panel, while possible, would probably be painful. That's why they suggest using a network (either ethernet or wifi) so you can use database software that can sort the files based on metadata about the recordings.