MacBook Pro 13" 2015 A1502 recording vinyls through headphone jack My 2013 MacBook Pro allowed me to convert audio from old cassette tapes and vinyl to digital by using a 3.5mm Male To Male Stereo Audio Cable from the player's headphone jack into the headphone jack of the MacBook Pro 2013.  In the System Preferences, you could change the headphone jack to function as input rather than output.  Easy. You could use Quicktime to record and other apps.

I found some old vinyl albums that I want to convert to digital but my 2015 MacBook Pro does not seem to be able to do what I mentioned above.  Playing the music  over the air and recording using the internal microphone would not be acceptable.  

Suggestions to accomplish this?
Record players typically needed a RIAA amplifier in order to get the same electrical signal levels as most other devices like tape recorders or CD players.  These were typically built into the amplifiers.

Today you need this separately.  I have had good experience with a Behringer UFO202 which plugs directly into a USB port and is immediately recognized by MacOs as a sound input and output device.

Note that this is a budget device at around $30.  If sound quality is very important to you, you need a more expensive device.

There is a review here: https://www.whathifi.com/behringer/u-phono-ufo202/review