Yamaha DX7 sysex
Sound patches
This page contains downloadable voice data as .sysex files. A sysex is a binary file that stores a sequence of system exclusive MIDI information mirroring the memory of the device: to transfer it you need to hook your Yamaha DX7 to a computer via a MIDI connection, then use one of the many sysex managers available for both Windows and MacOS to transfer each bank over.