The Captiole Reference is a CD player that has a built-in, very high-quality, linestage and a volume control. This player is a classic that sounds so much better than the competition at its price point, even ignoring the fact that it also has a built-in linestage, and really excels at being able to bring the rest of a system up to point where it becomes much more enjoyable to listen to.
And then there is the linestage, kind of thrown in for free. It is hard to over-exaggerate the quality of the linestage - we routinely run our $40K Walker turntable with Lamm LP2 phonostage through it, and it sounds quite excellent. By saving its purchaser the cost of a preamplifier, the cost of an interconnect between the CD player and preamplifier, and the cost of a powercord and any vibration control for the preamplifier, this player has an amazingly good price performance ratio.