I have a cable that fits the iPad headphone jack on one end, and has a stereo pair of RCA plugs on the other, which I plug into my preamp's AUX input. It should work fine on the average receiver, though a good hifi will reveal the limitations of the iPad's DAC and headphone amp.
milliHelen: amount of beauty required to launch one ship.
My Apple TV only has HDMI and Optical Audio outputs. Most audio equipment has either RCA stereo inputs or a mini stereo jack.