System assessment...

I would try acoustic room treatments first.  Even if you end up upgrading equipment, this will be helpful.  It's probably the most inexpensive route as well.  I found by adding absorption and diffraction in my rooms the sometimes shrill sounds I was hearing was improved. Rugs are easy.  First reflection points and ceiling absorption helped me.  Congrats on retirement!

Since you already have a good quality set of components, and are looking for the warmth of tubes without replacing major components, (and cost) you may consider ModWright’s Analog Bridge. I highly recommend it! Find out more here: 

https://www.modwright.com/products/analog-bridge/

I believe your gear is just fine. I would listen to @rbstehno and take a serious look at room treatments, either acoustic or electronic, or a combination of both. May not be as sexy as some new gear but I think you would be very pleased with the results. BTW I would put DSP in the catagory of electronic room treatment and if done correctly can be very effective.

As far as brick and mortar audio stores in the Twin Cities, I am aware of five.

Choice Audio which was previously mentioned. https://choiceaudio.com/

Mpls. HiFi https://www.minneapolishifi.com/

I believe these first two are the new kids in town. There is also,

Audio Perfection https://www.audioperfection.com/

HiFi Sound https://hifi-sound.com/

Stereoland https://stereoland.com/

These last three have been around for decades and still seem to be going strong.

I’ve done business with Audio Perfection and I believe they know their stuff and what they are doing, but they can be a bit pricey.

Room is the most important thing to consider 1st. Then synergy between speakers to room size, amp to speakers, amp to preamp, phono tt/arm/cartridge, cartridge to phono preamp, then cables.

I’ve used equalizers decades ago, and was using dsp for the last 3 years and imo, they are both a crux to something that isn’t working together that i stated above. The last 3 years, I moved from a custom built room within a room that was 26x16x15 with a large pair of Ushers that sounded great. Then we moved and my room is 16x12x9. For 3 years I’ve been using dsp and extra room treatments to get the bass to sound right. I decided to buy a new set of Revel speakers that had multiple smaller woofers that gives me the right amount of bass, sound staging, and imaging that I want without using dsp and 1/2 my room treatments. Using Jim’s methodology on system setup, the speakers are 1/3 (over 5’ from the back wall and 83% width of speakers to listening chair. I don’t hear the speakers, the sound comes from the back wall and you feel the musicians are centered.
 

You don’t or shouldn’t need an equalizer or dsp for your speakers to disappear, if they are decent speakers, speaker positioning will give you the soundstage depth, and imaging that you desire, same for bass capabilities. Read jim smiths book on get better sound for insights on how to setup your speakers and system. Or better yet, before buying any new expensive piece of equipment, hire jim to come to your house to have him set it up for you. 
 

I go or have gone to many of the audio shows like ces, the show, rmaf, Tampa audio shows, for the last 2.5 decades and I’ll bet only 25% of all the rooms in all these shows sounded any good. The old ces rooms sounded pretty good, a little bigger, more intimate. Now you have shoebox size rooms with large floorstanding speakers that overpower the room.

If you want to get into streaming (both from local ripped music on server and from tidal or Qobuz) think about a separate dac and use Ethernet or i2s inputs, not usb. Built in dacs to any integrated amp or dacs built in to a preamp are a compromise and a decent separate dac will sound better.

Why have a mixed batch of cables?