DB-01 connects to HP-01 with a standard midi cable, and takes 9v. Load your sounds onto an SDD card, and trigger them from the HP-01.

1/4" output is stereo or mono, line-level, but robust enough to listen through headphones as well.

The toggle switch increases or decreases the output volume.

DB-01 also sends power to the HP-01, so only one 9v power source is required to use both.