how do I connect my new LG smart TV to my old SPL 700 amplifier. I have tried red and white connectors to both devices but th

[donniemacd]

How do I connect my new LG 43LH57 smart TV to my old SPL 700 amplifier. I have tried red and white connectors to both devices but the TV cannot detect them?

 

[americanaudiophile]

According to the TV specs you don't have RCA audio outputs. You must have connected the amp to audio inputs.
You will need to use the TV optical audio output with a converter like this one
https://www.parts-express.com/parts-express-dac-digital-to-analog-converter-(51-compatible)--180-999
This is a fixed output so you will need to adjust the volume on the amp. Check the TV manual on how to use the optical output. You may need to change some setting in the TV menu.