Should I got full tubes or stick with hybrid amps?

@soundchsr

I'm still learning but my guess is that

(a) your corner windows are a problem, as is the glass front on your fireplace
(b) you have different items behind the two speakers (asymmetrical)
(c) your first side wall reflection points are an issue, too
(d) glass framed things are a problem.

I cannot see your rear wall.

So, my guess is diffusers and absorbers in various places.

Watch some Acoustic Fields videos as a starter. Here's the first pull on that thread:

https://www.youtube.com/watch?v=ZQIV341IUCg&ab_channel=AcousticFields

How would you treat this room?

https://ibb.co/pJ0pxVx

I gather you listen quite a bit from your desk.

1. In my office, I re-configured my desk, no drawers on the right, so that I sit off-center of the desk, thus centered on the speakers, and the monitor also centered on the speakers for all the music videos I stream.

Never better sound/imaging in my office.

2. Next: dogs OUT, the breathing, scratching, licking, lip smacking, farting of large dogs is not a good mix with concentrated listening.

3. I might try tilting those speakers up some, just to hear if any difference.

4. Do you pull that black chair out in front of your desk for focused listening? Slightly angled up might reduce tweeter’s output, may be advantageous regarding fatigue from such close focused listening.

5. Tubes: I say yes to all tubes, perhaps try something you can return or sell without too much loss.

two concerns.

a. speakers 88 db sensitivity, needs more power, i.e. 4 power tubes each side,

b. thus more heat. It seems like your equipment is behind those closed cabinet doors? Tube amps, especially that size tube amp wants lots of air for heat to escape.

6. Integrated Tube Amp, with remote volume, tone controls, and preamp bypass to bypass the tone controls if you want. Tone controls may be the best solution to your fatigue issue, neutral or adjusted for particular music.

Tone controls can be the real stumbling block since, for some un-fathomable reason, most designers have decided they are no longer required. Another factor is the type of sound you are looking for. You've stated that you don't like fatiguing highs. Depending on the tubes, even full tube set ups can sound harsh. One unit I will throw out there for you to consider is the Vincent SV-237MK hybrid integrated amp. It has a three tube pre amp stage with a very good solid state amplifier. Two of the tubes are 6N1P-EV's which pretty much don't have many sound changing replacement options. The third tube is a 12AX7 which gives you lots of options to change the sound. Besides bass and treble controls, it has a tone bypass, and something that used to be standard on just about everything, a "loudness" switch. I have owned one for awhile now and it is an excellent sounding integrated. At 150 wpc at 8 ohms, it will drive any speakers with ease.

Tubes Harsh? Huh?

I’ve used Tubes since 1973, 47 years, harshness never entered my ears.

always in the 30-35-45 wpc size (4 power tubes total)

Fisher Mono Blocks 80Z (EL37, substitutes)
Fisher Receiver 500C; 800C (7591, substitutes)
Current Cayin A88T 6550 or KT88

I think I put EL34’s in the Fisher Mono’s, -5 wpc, a vauge memory

Fisher’s used lots of 12...
Cayin uses 6....
Other Cayin’s now use 12 ....

I found both the pre 6’s and the Power tubes brands definitely sounded dirrerent/preferrable, but none sounded harsh.

I’m thinking I like the 6.... better than the 12 ....

You seem to be forgetting that those big output tubes have smaller tubes driving them. Those smaller tubes CAN sound harsh and pass that harshness on to the output tubes. I find that it is mostly the new production tubes that can impart harshness, but some NOS can also have those characteristics. If those tubes didn’t affect the tone, nobody would bother rolling them to find the best sound. It should also be noted that tubes for the most part are a lot more finicky when it comes to the speakers they sound best with.