Currently, the Hexpander and all MIDI converters are limited to six strings. There are two popular workarounds for more than six strings:
1) have two of everything: two Hexpanders, two MIDI controllers, two cords coming from your guitar, and split the systems. Each system can have a maximum of six strings.
2) Install the Hexpander and the Acousti-phonic and have six strings on MIDI, and the others on piezo-only. Depending on the music you\'re playing, it may work to have the bass strings as straight acoustic, and the rest as MIDI.