Great find. I've always believed that these guys are true artists.
Master of Mastering
The link below is to an article in the LA Times about Ron McMaster, mastering engineer at Capitol studios. I think it's worth the read (and it's fairly brief).
http://www.latimes.com/entertainment/envelope/cotown/la-et-ct-ron-mcmaster-vinyl-20160815-snap-story...
http://www.latimes.com/entertainment/envelope/cotown/la-et-ct-ron-mcmaster-vinyl-20160815-snap-story...