Is it Possible to connect Home theater speakers and amplifiers to an existing DVD player?

it all depends on the dvd player's outputs, most sony dvd players have optical digital outputs and composite audio output which will transmit digital signals to most compatible home theater receivers. check your home theater system's different inputs and get back to me. if there are no digital connections anywhere, then 100% likely you'll have og connection available through RCA cables, but no digital sound quality. you want digital too!