Emerson TV and a oldSony receiver

[Saronta]

I have a Emerson hd TV and a old model Sony receiver

 

[americanaudiophile]

Without model numbers there is no way to be exact.
If your TV has an analog audio or headphone out you can connect that to the receiver with the correct cable.
If your TV has optical digital audio out and your receiver does not then you need a DAC like this one
http/www.parts-express.com/parts-express-dac-digital-to-analog-converter-%2851-compatible%29--180-999