Dear No regrets: Ok, check what Lew suggest.
+++++ " My supply does have variable pots to fine tune the speeds for 33 and 45. I can get the table to spin correctly, but then for no reason at all it justs slows way down. " +++++
I don't know which kind of pots your TT has but from what are my experiences about and taking in ount what you posted: +++ but then for no reason at all it justs slows way down... ++++, maybe there is something wrong there because that kind a problem is a sign that a pot could be going out of specs and with the working time in the future that problem could be worst.
Btw, have you the trouble in both speeds?, if yes then I think that maybe is not a pot because it is almost imposible that both suffer a damage at the same time.
Now, for any one could to have a precise diagnosis it is desirable that the check-up on your TT have to do it when the failure is present.
I can't say nothing more except: good luck.
Regards and enjoy the music.
Raul.