Do I really need a pre-amp?

Do you need one? No. However, in most cases you are better off with one. Most CD players (there are a few exceptions, mostly premium players) use relatively inexpensive OP amps for the variable output stage. You'll get better sound running the fixed output into a preamp.

jpshinn: you are apparently unaware that the audiogon discussion forums may be searched via a fairly powerful search engine. your query is only slightly less rare than freckles on howdy doody knockoffs. remember the rules for crossing the tracks: stop, look and listen. -cfb

Which amp do you have? I have a Sony XA7ES CD player with a variable output, & fixed outputs. This player has a high quality variable analog output, accessable by the remote.
It was Sony's top CD player until the SACD1 came out. It sold for $3000.00 new, there's a used one on Audiogon today for $1050.00. This is the average used price. You can buy this player & use it for at least a couple of years, & probably sell it for what you paid-I did this with my last Sony ES player.
This player also has a "balanced" output. It is NOT truly balanced, and is not a variable output either. Unless you have a truly balanced amplifier, (Rowland, Levinson, Krell, etc.), this won't matter anyway.
Tell us which amp & speakers you have, & you'll get input from members familiar with your components.

I recently used a fairly high end CD player directly into a good amp for about a year or so. The cd player has a high quality, analogue domain volume control built in. The sound was concise and clear. I recently purchased a pre-amp to match my power amp. The sound retained its clarity, but now there was much more body and heft to the sound. The soundstage also got wider and deeper, due, I would guess, to the increased body of the sound including a richer lower end.

I suspect that just as with a power amp, there is no substitute for power, and the "preamp" of using a cd player's variable output just can't match a good preamp of similar quality. In other words, a good cd direct into an good amp is fine, but a good cd into a good preamp into a good amp might be as a rule better. That has been my experience recently, in any event.

pcanis