Sony SCD-777ES Question

I have a Sony SCD-777ES cd/sacd player in a secondary system that I enjoy very much. Does anyone know what brand and model of d/a converter chips are in the player? Are they Sony's own or someone else's? I am very curious.
One of Sony's recording engineers in New York City told me the chips are of Sony's own design and manufacturer. He also indicated that Sony often provided many of its chips as OEM parts to other builders. Great player, great sound.