Well, I've tried wading in from both sides of the pond and think that some good points have been made here both pro and con. If you are running directly into a tube amp, you might get very good results via the variable output. You already have tubes to soften the digital nasties, and many tube amps have high input inpedance, which lends itself to such an application. It would certainly be the cheapest avenue, and possibly the best sounding. In other words you have nothing to lose by trying it out. First hook up the direct variable connection from the CD player to the amp inputs (keep the level low to start), and see how you like the resulting sound quality. The problem, as I see it, is that you will have to disconnect the CD player when you want to use another source. So, what that effectively brings you back to is the compromise of adding a passive preamp to gain volume control and switching for all sources -- in which case you might as well use the more direct fixed output on the CD player into the passive preamp as someone else has already suggested. And yes, that can limit dynamic impact somewhat. But heck, if you like the direct variable input enough (which may add an active output stage internally), then it might be worth disconnecting and reconnecting the player to facilitate the use of all your other sources. As with most comparisons, your ears should aid you in your final decision.
Do I really need a preamp?
I am considering another preamp to go with my CJ 2200. Am thinking about a CJ pre to go with it. However since my main source for listening is a cd player which has variable output, why do I need a good preamp. I have an Adcom GTP 450 tuner/preamp which will do the job for radio, tapes, etc. That said, how can I run cd and pre into the amp? As always, your help is appreciated.