Absolutely. Your cable/sat box will have a digital audio output AND an analog stereo output. You just run a digital audio connection from your cable/sat box to your receiver, and you'll get Dolby Digital 5.1, if the channel is sending it. If the channel is only feeding a stereo signal, you can turn into 5.1 with Dolby Pro Logic II, or even 7.1 if your receiver has Dolby Pro Logic IIx. Almost all new receiver's have both now.
You can then run a standard stereo audio hookup from the cable/sat box to your TV so you can listen to the TV without turning on your sound system, if you chose.
