In order to play a DTS CD, you would need a CD player with a digital output, so that the raw stream is sent to your receiver, which would then do the DTS decoding. If you try to use analog outputs from your CD player, you'll probably get screeching noise.
SACD's are often released in a hybrid format, with one layer containing the SACD audio and another layer containg regular CD-audio that can be played back on any CD player.
DVD-Audio discs usually have a DVD-Video portion on the disc containing either a Dolby Digital or DTS format for the recording that can be played back on any DVD player. This is not the same as the higher-resolution DVD-A data on the disc, which requires a DVD-A player to use.
