Warm Tube Amp(s) to Tame Hyper-Accurate Speakers?

Perhaps warm tubes is what you need, not a warm amp.

Also, room acoustics might be at work.

Before you swap out gear, try to analyze your room with REW. The time and trouble it takes to learn to analyze your room is a fraction of the hassle of playing gear-swap whack-a-mole.

Keep the amp, sell the Spendors. No amount of front end, cable, or source changing will fundamentally alter how a speaket is voiced, and if they're too hot, they're too hot.

hold on a second... what speaker cables are you using to connect the 275 to the Spendors?  That might make all of the difference in the world here.  Let us know before doing anything drastic.

Perhaps it’s not your equipment but your room acoustics.

I bought Splendor D7's based upon all the fabulous reviews a few years ago now, but have regretted it as soon as they arrived.  This D series is not my idea of a great English loudspeaker. The upper kids and lower treble range is sublime on perfect recordings, but unfortunately those are not the majority of my vinyl recordings that I have purchased during my 50 plus year hobby. I love transparency, but bleached sound is not for me. I even have older tube equipment that is more mellow than most SS sounding modern tube gear is to me.  I don't get the hype for this series personally.