PD-7, PD-9: Differences between the PD-7 and PD-9 April 12, 2023 08:47 Updated Follow The only difference is the size. PD-9 is 10" diameter and PD-7 is 7.5". Another difference, not affecting performance, is the texture of the pad. Related articles TD-02, TD-07, TD-17, TD-27, TD-50, TD-50X: Pad Compatibility Chart PD-9: Specifications PD-7: Specifications BT-1: Selecting the Pad/Trigger Type for the input within the V-Drums module (BT-1 SENS) OCTAPAD® SPD-30 Turning the Phrase Loop Light Off