as far as randy rhoads tone goes you have to consider outside factors, such as how the records were all mixed then, the 80s saw the rise of the SSL console a very CLEAN, but great sounding recording console, and some crazy new horrible sounding but expensive and "cool" digital effects, so alot of the records sound thin, its the nature of the beast, plus this might be off color for some but if you think about that era, they were doing alot of cocaine and cocaine can make things sound warm and fat, which is cool unless theres a record executive breathing down your neck so you compensate by recording and mixing things thin... it sounds like a joke but its true i actually have heard a funny story about an SSL console frying out and when they pulled it apart they found some ummm "residue" that had been lying in its chassis had shifted when they moved it and now had spilled over some circuits and burned
Who here DOESN'T use the "Classic V" grapic EQ set