If the original recording was not re-mastered for digital. A problem with all the earliest CD's that were originally vinyl records was just as Blackhorse suggested, they all sounded tinny. The vinyl versions sounded heaps better. I recall I even had a cassette tape recording of a vinyl record that sounded heaps better than the CD of the same album. I ended up some years later purchasing the remastered version. I had wondered since whether that was done deliberately for marketing reasons.

Not sure about FLAC, but Toast on mac converts 24 bit or/& 96 KHz audio to audio cd or standard 16 bit 41.1 KHz without issue in my experience. However, I'd prefer to use a proper audio pro editing program for the purpose of such downsampling.