Many digital devices now support external clocking. Generally, if the unit has a digital output, it will probably have clock input and output connectors. The most common format uses a BNC type connector (tall, silver barrel on the chassis, twist-lock connector in the cable). This format calls for a special Word Clock cable. You’ll find this connection (external clock input) on digital consoles, DAT machines, CD-Rs, sound cards with digital I/O, processors, and of course, A/D converters.