The TM-D1000 has a non-standard word clock input curcuit that can damage word clock output of the original 2408. This damage will only occur if you turn on the 2408 with the TM-D1000 turned off. We do have a modification available to prevent damage to the 2408 word clock connection. This modification is not covered under warranty, and can be arranged by contacting Technical Support. Please note that the 2408 mkII and mk3 do not require this modification.