Depends on the cable. If it’s a proper AES/EBU cable (110 Ohm impedance,) you should be fine for several hundred feet. If it’s a generic mic cable (with a different impedance than what the AES sockets are expecting,) they tend to be fairly hit and miss, and people tend to not be able to get more than a few meters out of them, (something to do with the different impedance causing the signal to be reflected back inside the cable, resulting jitter/clocking issues, and ultimately errors that result in loss of sync.)
