The Sony 7010 has a Sync Mode select switch that seems to override the digital input for clock source. The switch allows you to select Internal, External or Video sync mode. Even when the DAT Machine is in Digital input and record enabled, the clock source for the machine is still the DAT machine (because Internal sync was selected). Only when the machine was put into External did our particular clicking problem in DATa go away. This machine will need to be physically switched every time a transfer is made.