Another basic newbie question.

I'm not an audiophile but recently more-or-less inherited an older high end system. There is a thread here about that story. 

This is a simple question regarding the Audio Research LS16 preamp. I have the user manual but it is short and assumes that the user is a seasoned audiophile. I think I've got the basics figured out. I understand the RCA inputs and outputs. I have high quality XLR cables for output to the amp. But there are two inputs I do not understand. They are labeled CD Bal and Aux Bal. I understand that 'bal' is for 'balance' but otherwise I do not know what these are for or what that means. Are there CD players with XLR-out ports?

Thanks for your assistance.
n80, some source components (e.g., CD players) DO have balanced (XLR) outputs and that is what you would use these for.  Others can chime in on the relative merits of balanced vs single-ended (SE) connections between components but, basically, balanced connections can be much longer without being subject to picking up noise and the gain is double what single-ended connections provide (I haven't mixed them but I would imagine this could lead to having to drastically adjust the volume when switching between SE and balanced components in a system).  Don't worry if you have a single-ended component - looking at the back of the LS16 version I think you have, you could use either the AUX SE or TUNER connections.
Thank you. I was mostly just curious. I've got two decent CD players and don't think I would bother spending more on a new one with balanced output at this point.

I'll be getting some decent RCA cable though.
“You'll be an "audiophile" before you know it......”

He already is. He just doesn’t know it 😁
I'm not sure I have the ears for it. I like it. I appreciate it. I can hear differences in cheap vs better systems. But I'm not sure I'll ever get to the level of sensitivity _and_ recognition I hear described among audiophiles. Not sure I'll ever fully appreciate the system I have.

But I will enjoy it.
I wouldn't worry about being more analytical.  Not necessarily a good skill to have.
I think you'll be surprised at what your ears pick up after you've been listening to the system for a while.  There are all kinds of subtleties to good sound and your ears will begin to sort them out.  I remember in the early days thinking "Oh, that must be what they're talking about."  Of course the downside of all of this is that you'll be able to identify crappy sound in a heartbeat (and possibly won't be able to listen to it anymore!). :-)
As long as the emotional impact of the music exceeds your attention to the equipment that provides it, you'll be ok.