The reason why you couldn't get the Samsung and external DAC to work is that the default setting for digital out on TV's is Dolby Digital. It must be changed to PCM, and this is usually difficult to find in the menu. I did just look at a new Samsung manual and it is there. I have also looked at new Sonys (have one about 2 years as well) and it looks like they still have the analog out, however it is a 1/8" stereo mini plug that may be labeled "headphone". You would need a 1/8" mini to RCA cable. This output can be configured in the menu for variable or fixed.
Here's a good little inexpensive DAC if you need one,
https://www.amazon.com/Digital-Analog-Converter-Optical-Toslink/dp/B005K2TXMO
And if you don't need the optical cable, it's only $20.
Good luck!!