I have the old 1974 vintage Pioneer sx-750 and it has a tone switch on the front and also the "Duplicate" switch,what do these do exactly,thanks 


/akdatabase.org/AKview/albums/userpics/10004/Pioneer%20SX750%20Service.pdf
/akdatabase.org/AKview/albums/userpics/10004/Pioneer%20SX750%20Service.pdf
/akdatabase.org/AKview/albums/userpics/10004/Pioneer%20SX750%20Service.pdf

