What seperates "hi-fi" from "mid-fi" in cdp's?


I find that in my search for the right CDP I really don't know what, mechanically, seperates the good from the not-so-good. Although I understand which brands are more highly regarded than others, I don't understand why.
Along those lines, I would also really appreciate a very brief description of the primary working parts of the cdp and how they differ among "levels". For instance, how does the number of bits matter? Or is it just another useless audio stat?
Or, if I am asking a bigger question that I think I am, maybe you could direct me to a good reference for this issue? Thanks JB3
jb3
Ncarv - I'm guessing you must have been joking cause that just ain't so. You yourself have an excellent example of a fine CD player in your own system that can be had for a very reasonable price on the used market (as can many others), and yet can compete sonicly (is that a real word?) with some far more expensive alternatives, and likely even better them in some systems and to some people. I'd say anyone who chooses price alone to be a telling criteria to judge this is making a big mistake, especially in the price range being considered by the poster. A fool and his money will go separate ways.

Marco
I agree with the above posts about listening and forgetting about specs and bits. I disagree with the above posts that say that 16 bit is outdated. The 47 Labs DACs are 16 bit are currently produced and sound very refined.

Having said that, some things to look for are a beefy (and/or outboard) power supply and minimalist circuit design. Also, manufacturers that pay attention to resonance dampening (heavy chassis) and shielding (copper case) usually have fine sounding cdps.
True, Marco, BUT . . . I'm really using it as a transport and running it through a DAC and, with wires and iso devices, it costs about 3x the player, used. No doubt you can get a real nice player in the mid-fi range, but it's also true the more you spend, the better you get. I'm not knocking mid-fi. A Honda Accord is a real fine car, but it's not a Mercedes.