Thought I would post this for all his fans that don't subscribe to Vintage Guitar Magazine. In an article, Wolf Marshall states:

"Di Meola has played and endorsed Ovation acoustics since the mid '70's. Early on, his favorite was a Balladeer strung with Guild Spanish light-guage strings and attacked with a heavy Gibson pick. Today, he has two Ovation 1769-ADII signature models - Custom Legend and Adamas - equipped with a MIDI pickup and OP-PRO preamp, they have a spruce top, 25 1/4" scale, abalone inlay, and five-piece soft-V neck. This guitar was played on Cielo e Terra. He strings the Ovation with D'Addario EJ16 strings"