Poor sounding analog?

After 25 years of not having a turntable in my system, I finally purchased a new rega RP3 which came with their ElysII MM cartirdge.

I pulled out one of the 500 or so albums in my basement that I used to enjoy, cleaned it thoroughly and was incredibly dissapointed in the sound.

I have a McIntosh 2300 preamp which has never had any burn-in for the phono preamp section. However, I cant believe that new tubes would sound this flat.

its a very simple unit to set up. Nothing tricky.

What am I doing wrong? Thanks in advance for the help!