If you have a digital reciever you should be able to run straight into a digital input on your preamp. If you have an old pro-logic reciever you may be in trouble.
5 responses Add your response
The cheapest thing to do is to take the analog out from your Samsung Set Top Box (STB) and connect to your pre. If you want to take the digital out (as you suspect, 5.1 for some OTA programming) you WILL need a Digital Surround Processor with a Dolby Digital (DD) Decoder to take the 5.1 audio feed and make it available to an analog preamp. This will allow you to stay away from buying a receiver or preamp/processor combination.
You have several choices with most DD decoders, 1) you can create a 2-channel signal as you describe; 2) you can add a center channel speaker (used largely for dialog) and output 3 channels from the decoder; 3) you can add center, left & right surround speakers and output 5 channels; or (lastly in this case) you can do the Full Monty by adding 3 speakers and a subwoofer.
The cheapest, quality, standalone (non-receiver) DD decoder that I am aware of is a discontinued item from Sony. The model number is SDP-EP9ES, and is referenced in several AudiogoN forum threads. The user manual is in PDF format here. There are several for sale on AudiogoN now for between $175 and $200 (I have no connection with either item).
This should allow you to meet you interest without getting too far down the slippery slope into home theater! :-) Bob.