Released in the '80s, the PDS 2000 might be called the harbinger of the Line 6 DL4. It features three modes—delay, sampler and trigger—which are the three things the DL-4 does. The delay mode needs no explanation, while the sampler function is a two-second looper accessible via the left footswitch. In trigger mode, a footswitch is connected to the trigger input, and the footswitch plays a stored loop just once. Where the PDS 2000 actually trumps the DL4, is that a click track or drum machine can be used instead of a footswitch to trigger the stored sample.