@innersound300 imo, listen to @aricaudio who knows your preamp design.
I was about to suggest the same as Aric. I’m currently using a 6SN7 preamp with various tubes in the stable. Every single/different tube I've tried (NOS vintage or new) offers a different sound, presentation, level of detail and stage/focus can change. More info about your existing tubes in that preamp may help too.
i.e. my NOS Sylvania 6SN7 long black plates are uber detailed and almost too forward and open compared to my other/smoother softer PSVane or TJ Full Music ’SN7 tubes, or new reissue Tung Sol 6SN7s a bit more rolled off. However, with your speakers and tweeters, might be a match for you. It’s a balancing act.
Have you already tried a few other 6SN7 or 6SL7 tubes in your preamp, as Aric is kindly suggesting? This is a start and common to try among members here. He mentioned caps too, yep, these can be changed too, ask Aric more imo.
Amp/Cables/Speakers:
Reviewing your Innersound 300 amp, (i.e. similar to Coda 3.3 Stage), right?, I don’t think your amp is a culprit as much as it might be fining a combination of the 1) correct ’SN7 tube in your preamp 2) if you’ve not already tried possibly more transparent interconnects (yes it can help) to try on loan, between your sure and preamp, and preamp to amp 3) then if still not resolved, ask your PBN speaker manufacturer if there is a more open crossover capacitor or slight crossover/x-over change to open up that tweeter a bit more, is it rolled off some? Maybe so, worth asking them. Some small changes might go along way here first.
imo, several things to try long before jumping off the cliff to another preamp.