Pass through is rarely more than stereo. You seem to have forgotten that issue but even if you had optical, for most content, all pass through is stereo. Widely discussed.
The cheap fix is some other box/device that has the optical out.
Recently I bought a 46" LED TV from Samsung (UA46EH6030R). The problem with this TV is that it does not have any digital audio output ports on it; it has two HDMI and 1 headphone jack. Now, I have a Yamaha receiver at my home which does not have any HDMI connectivity options but only has RCA and Digital (Optical/Coaxial) inputs.
I need to now connect my amplifier to my TV so that the receiver would be able to output audio from the TV. I have tried the 3.5 mm headphone jack to RCA option but that would only provide me with the stereo(2.1 channel) output; my concern is the 5.1 soundtrack from the movies on USB stick attached to TV.
Requesting u all to please help me with certain feasible solutions as I am badly stuck with this setup.