Line 6 variax Guitars respond to a limited subset of standard MIDI messages. Mostly PC messages to change Models pre stored in the guitar and CC mesages to control Volume and Tone.

Other than this, full control of all Variax functionalities can only be achieved by Sysex messages. This documents tries to document the majority of the most relevant messages players would require by reverse engineering the communications that ususally occur down the VDI cable.

Note on old generation Variax: some models and/or firmwares might need to receive a SendModus Sysex message before it can be controlled via MIDI (See SendModus below)

Variax will also send MIDI CC messages when the Volume, Tone, Models and tunnings knob is actioned; as well as when the pickup selector switch is also actioned.

To achieve this, you need to send the SendModus Sysex command below. Once this is done, Variax will start trasmiting MIDI messages out. For only receiving, this is not needed.

SendModus (for Variax to send MIDI Out) otherwise it will receive perfectly without.

Credits to Joe Bear

07 05 - product ID = JTV (I am assuming - this seems common for all JTV SysEx I've probed so far)

<12 bytes> formatted as <six, two-byte string tuning values> - first two-byte value is for the 1st string (would be Hi E in concert pitch), last two-byte value is for the 6th string (would be Lo E in concert)

So that just leaves the format of each of the <six, two-byte string tuning values> to be defined. They seem to be a sort of two's complement made up of the LSBs of each of the two bytes.