First, you need to decide if you will stick to MM or change to MC in the future.
I would first upgrade the cartridge. If Phonomena II supports MC, I would try something like Denon DL103r. I think you will feel the difference immediately.
Then, you can think about upgrading the phono stage to something like Allnic H1202 or Herron VTPH-2A.
I use Denon DL103r and Allnic H1202 and it sounds pretty good.
I also use Ortofon MC20 super, SoundTradition's Live! MC-10 SUT, and Magi Phonomenal MM which sound better than Denon and Allnic.