hifi engine

JVC PC-Y777 Looking for service manual, possible mods

Hi, new to forum, have been having fun trying to restore old stereo equipment, boom boxes, speakers, and guitar amps & effects.

I have an old JVC PC-Y777 portable system that I would like to upgrade for the garage, maybe clean up the sound, new speakers, may add a new amp circuitry & bluetooth connectivity.

If anyone has access to a downloadable service manual or schematic, it would be most helpful.

Big thanks.