Hi Randy,  You can find almost all the documentation  pertaining to the
Marantz Pianocorder at Mark Fontana's "Pianocorder Resource" page:
http://dp70.dyndns.org/pianocorder/doc.html

The manuals are all in Adobe Acrobat format and can be printed for use.
Full schematics are included.

Hope this helps.
George Livingston
Miami, Florida