KEMPER + TECH 21 MIDI MOOSE

The Midi Moose can run off a 9v battery as well as mains power and works perfectly with the Kemper.

Nope. The KPA doesn't offer phantom power on midi input/output.

Check this: Simple little hardware mod to my Kemper

Quote from Jimmyno

Check this: Simple little hardware mod to my Kemper

just be aware that this will void the guarantee, on top of being a very dangerous and potentially fatal procedure unless you are a professional.

Yep, of course it does void warranty and it is dangerous.
Honestly i'd go with a 5 to 7 pin midi cable.