Phono stage upgrade

It is the tine to upgrade my phono stage. For the first year of comeback in vinyl I used a heavy modded NAD 1130. For its price ($200) it is superb. Now, I would like to try something else.

My budget is $600 (including the power supply).

My cartridge is an Ortofon Super OM40 (MM).

What is in your opinion the best (used) phonostage under $600 for Moving magnet?

Thank you for your help.