Just a bit to bright

Lots of poor to average recordings and that cannot be avoided. The mod with the Jupiter caps will also help those. Yes, play with toe-in as well as sound absorption panels at the first reflection point.

Thank you for all the replies!
Lots of great food for thought which is exactly what I was hoping to find here.....
A couple small bits of information:
My speaker cables are 10 gauge, 462 strand OFC
Interconnects are AudioQuest G-Snake
My speaker sensitivity runs about 85 dB (@2.83V), if you adjust for a 4 ohm load they're around 83dB (@2V)... Based on my test results using the 1 watt, 1 meter distance standard.

I have a few friends that would likely allow me to try an amp or place my speakers into their system and look for the brightness to remain or disappear or...

With regard to toe-in, my speakers are designed with a mid transmission line/pass through.... The mid-range driver has an open tunnel to the back of the cabinet. They should be placed 18" inches from the back wall and with straight ahead positioning. They really do offer great imaging with vocals in particular.

I'm really intrigued with the idea of swapping out some of the Dayton components! I built the crossover boards in a way that provides easy access and removal, so Grannyring, I may take you up on your offer of help.

I've also been exploring an amp by Class D Audio. Reviews state it has a very warm tube like sound. With 250W @ 4 ohms I suspect it would drive my speakers well. But... I won't be pulling the trigger anytime soon. I've got homework to do.

Patience. I've put my wallet away and will continue exploring the simple and inexpensive adjustments.

Thanks everyone!

Jeff

They should be placed 18" inches from the back wall and with straight ahead positioning

This statement may give a clue to the problem here. So whether you have a 10 foot long room or a 100 foot long room, they should always be placed 18" from the front wall? I don't think so! The amp might be a problem but not the first problem you should deal with.

Have you experimented with the difference between bi-polar outputs vs. mosfet outputs? I mean even to audition? Your NAD will never satisfy you. It's simply not high enough caliber given your op. There is a marked difference in general between the two. Mosfets are softer on the top end, however, really good bi-polars make no apologies. They are faster. But I'm convinced you really just want something better than what you've got. You really are still at square one in terms of what topology pleases you. An excellent bi-polar example would be the Harman Kardon Citation 16. A legendary amp which is imo second to not many sota amps even today. It came out around 1980. A competitive mosfet amp would be an Acoustat TNT200 or 120. Same era. Both are still highly sought after. The newest HK offering apparently has the same basic circuit as the 16 which is in itself revealing.

Great advise from Kiddman. I often wish I had learned that lesson much earlier in my "audio career".