Next upgrade to an entry-level system?

At almost every level of spending, the speakers are going to have the most noticeable effect on your sound. After that, you are on to matching components and selecting specific features to improve the music you like best. If you are going to upgrade your amplifier, I think you will need to spend three times what the unit you presently have costs (or find a used unit that when new cost as much) in order to have a significant difference in sound. A sensible upgrade path might be speakers-->amplifier-->subwoofer. The turntable and cartridge would be the least likely to have much effect by upgrading.

First time poster! Hi everyone. 
So I decided to respond to this post because I just recently bought into the hype of high quality power cords. I was blown away what a NRG z3 cord did to my integrated and power amps. Also the isoacoustics pucks and Gaia and Gaia Neo, made a significant difference to my kefs that were literally just sitting on stands or shelves.

Maybe jump to Chesky LC-2 speakers and catch up the source and electronics later.

Think for money invested vs sound improvement a second sub will do it. Adding another sub really is a game changer. Once you get 2, you will be happy with them for a long time, it's not a short term investment. 

DAC, Cart, cables, are all rotating pieces, while do bring improvements are not the best bang for the buck, or last a long time in your system. 

Speakers are always the best change to sound, but also the most expensive, and take the longest to setup. Sadly once you change speakers, you then want to change everything else to get the speakers to sound how you want them. 

Forget Wharfedale, Mission, etc. Monitor Audio Silver 3Ci will way outperform. Upgrade TT to a Rage P3-24. New or used.