I'd like to say that I'm by no means an expert- but i believe you would get the most from improving your speakers and maybe either a etyer phono, or an integrated amp with a better phono card. Your record player is very capable, and can handle a better cartridge than the Red Ortofon- even though I had that same cartridge for three years and thought it was decent. Honestly, I cannot see a "weak link" in your system- but the speakers can always be upgraded and will most definitely visibly improve the sound. I fond that, to my ears, Harbeth and Tannoy soud very good with vinyl. They require little power and (at least in my caee) produce enough bass without having to integrate a subwoofer.

Good luck!

Your amp and speakers are solid. The cart is the weak link, IMHO. I would upgrade...make sure it's high compliance as your tonearm is low mass. Not sure what your budget is, but you might want to try a moving coil cart and a new external phono stage. That combo would bring about a big change in your playback experience..

The cart and preamp would be the next steps.

Even swapping the red ortofon out for a Blue will dive deeper into the grooves and reveal more details. Over time I’d shoot for an external phono preamp.

The hinge pin to this question is "most bang for the bucks". With that stipulation, I agree with the general consensus (i.e. upgrade the MM cart, first, and contemplate upgrading the phono section later. The Ortofon Blue would be a logical step up or the Bronze or Black, depending upon how much money you'd like to spend. There are other good choices, of course (e.g.
Goldring; MoFi). If you aren't accustomed to setting up a cartridge, have it done by a professional.