Do you mean there are no RCA connections on pro audio gear? Of course not //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif They use 1/4" TRS (tip-ring-sleeve) connections, mostly, or XLR connectors for the balanced connections. You can always buy adapters to go between the two. I needed to buy some adapters to hook my DBX 215 EQ up to my NAD 3020 integrated amp... You don't need a special CD source, that's the whole point of an additional preamp.
Honestly, I've never figured out (my own personal audio rant follows) the need for huge amounts of power at home. I'm not just talking about tubes, but using lower amounts of power from solid state amps (like 80w-100w unclipped) to high efficiency speakers, like a line array or horns, makes a lot more sense to me. Going from 85-6dB/W to the mid '90s will make a light and day difference in output level. Plus, speakers are cheaper to build than buying more equipment in front of them //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif