Found your manual here
http/esupport.sony.com/US/perl/model-home.pl?mdl=STRV220&template_id=1®ion_id=1&tab=manuals#/manualsTab
With it being 11 speakers it doesn't sound like a surround sound setup, In order to make these work you would need a proper power amp.
The amp will depend on the speaker ratings - find out what these are and if they are 4/8ohm or 100v line.
Find the place where the original owners amp would have been and find out how many speaker cables there are. The 11 speakers could be split into zones or simply left & right.
DO NOT connect your amp to the speakers until you know the above as you will probably smoke it.