I am considering several used sme 20 turntables.

At a substantial savings, I would probably go with the second generation power supply. The second generation power supply is quite competent. The third generation looks cooler, though.

I previously owned an SME 20/2 (older power supply). It is a superb table and highly recommended.

Hi, I have to agree with both posters above. You won't go wrong with any version of this table.

I have owned the most recent power supply as well as the previous one (twist knob). (20/2 IV.Vi arm)

The newest power supply is a little more transparent and continuous. It's a nice step up. Dramatic no. Nice yes.

I'd try going to the newest version but negotiate it down a little :)

It's big step up over you LP 12. You will be amazed at the difference...no matter which power supply option you choose.