Hi Joe,
I have not listened to any of their albums for many years, don't
recall any problems.
Are you listening to the original LP pressings on vinyl, or CD reissues - early CD's tended to sound bad because the
engineers hadn't the sense to re-equalize the masters for digital, they
simply used the LP masters which were adjusted for the peculiarities
of that technology (i.e. vinyl played with a stylus).
Later CD remastering tended to be quite good.
If you are auditing LP's, make sure your stylus is not worn, has not accumulated dust or other debris, is properly aligned to the record groove, and tracking pressure is proper. Also, old LP's may have problems if they are worn, warped, etc.
Thomas.