How activate Kemper Level Tuner with any pedalboards?

And your "pedalboard" is what?

If any of your boards can send midi volume (CC7) you can call up the Tuner by sending a value of 0.

The official CC# to show/hide the tuner is CC31, A value of 1=show, 0=hide.

Unless somebody that owns one of those can help out here, you will need to check with the manuals or contact Tech 21 Midi or Voodoo Labs about how to configure a button to send CC31 values.

Assign one of the buttons on the Ground Control Pro to CC#31.

Quote from benvigil

Unless somebody that owns one of those can help out here, you will need to check with the manuals or contact Tech 21 Midi or Voodoo Labs about how to configure a button to send CC31 values.

I have a Ground Control Pro, give me a couple of minutes and I'll fire it up and assign a button myself to make sure it works, then I'll post a step-by-step walkthrough.

Okay...

First, enter setup mode (hold down the two setup buttons at the same time).
Next, hit the "Instant Access" button (#6). The screen will display 1.CHXX CTLXXX (the Xs will be numbers, mine is already programmed for my gear so the numbers mine is displaying will be different). The first number (1.) indicated button #1 on the Ground Control Pro (on the top left). Next is CHXX, which indicates the MIDI channel that button is assigned to. If your KPA is set up to receive OMNI, it won't matter which channel you select. Next is CTLXXX. The is the CC# that you want to change to 31. Hit the right cursor button to scroll to the CTL setting (it will start blinking). Use the "DATA -/NO +/YES" buttons to scroll to 31, then hit the edit button to exit.

This will assign the tuner to button 1. If you wish to assign it to another button, use the "BANK up/down" buttons to scroll through until the first number on the left of the display shows the button # that you wish to assign to the tuner, then use the steps above to assign it.