Any theories about how to do this to get the BEST audio I can from vinyl records in mint condition....
they don't exist on CD or in any digital format that I know about...
Get a high quality turntable with a good arm and a cartrdige, set it up on a shelf or a well-isolated stand, clean the LPs carefully before going any further, connect the turntable leads to a dedicated phono preamplifier or an integrated amp with phono inputs , take the output from the amp/preamp and connect them to a sound card line level inputs. This can be a built-in or dedicated PC audio card or a USB device such as the Behringer UCA202, few built-in/dedicated cards have RCA inputs so you might need a rca-to-mini lead.
Then you need some recording software. Audacity is free and pretty flexible. Decide on the bit-depth and sampling rate you want, there is no practical benefit in going above 16 bits or above 44.1 khz - you will just get bigger files. 16 bits will easily capture the dynamic range of **any** LP and 44.1khz will comfortably capture everything up to 20Khz - covering the audible range.
You will need to experiment with input levels you want the input to peak just below 0db, I would tend to go for -3db which will add a little noise but will avoid clipping. Once you have the level correct I would record the LPs a side at a time, you can edit them down afterwards. Audacity has a declicker should you need it.
You want to record at a lower level. Clipping on a digital recording sound terrible. You can increase the volume digitally later.
Make sure your software have some noise reduction utility and editing utility. This is for removing any pop and click and background vinyl noise.
I'm still experimenting trying to find the optimum setup myself. I have done enough so far to have figured out this is a labor-intensive process! I've tried Audacity and Golden Records via USB from my turntable to laptop. Audacity seems to offer more user-selectable inputs while Golden Records is easier to use. Good process outlined by Nick above^.
I used to prefer listening to 192/24 and 96/24 vinyl rips but after a while I realised they were inferior to the CD - if the CD was properly mastered.
Look at a vinyl rip through a spectrum analyzer, there isn't much there above 16 KHz... this is why the rolled-off highs sound pleasing to some people.
If the vinyl recording has a dynamic range of 13-15 dB and the CD version has 5-6, I'll rather listen to the vinyl.
If they are equal, then the CD will be superior in every way and I'd rather have that.
I use the turntable output directly to my PC line-in. And use Audacity to record the playback. After which I apply the RIAA EQ-curve and then you can get the peak output to just about perfectly.
(If you use this method you will need a sound-card that has a high S/N ratio)
Even with 16-bits you can capture what's on a vinyl, and more. The dynamic range of vinyl is somewhere around 80 dB .. so you need about 13-14 bits to store that. The other bits will basically contain noise only.
Please note that I'm talking about storing the final rips here. For the A/D conversion (and especially post-processing) you can and should use a higher bit depth of course.