need advise, which is the weakest link in my audio chain

Thanks. Nice photo. Yes, that looks like a challenging room. And the solution will be lots of dampening.
 

Are the big rectangular  objects in the corner bass traps? Your room looks perfect for tube traps. I would go to their site. You’ll see that three in front are used for a challenging room. Also carpet down to the speakers.

Also on the walls. I am not an expert by a long shot… but those do not look like they would be really effective. 

I would continue to work on your room.

Looking over your equipment. I would say, given what you have said, Bryson is probably not a good match for your tastes (or mine). While quiet and detailed, they are pretty analytical and the opposite of sweet and musical.

While upgrading your DAC will gain you a lot. I think the first thing you want is to get your central components correct to your tastes (preamp and Amp). I think you would be much happier with a tubed preamp (as high a quality as you can afford)… and a warmer amp… since your speakers are 88db… not tremendously efficient, you will probably have to use a solid state amp (tube would be preferred, but I am guessing a good 60wpc tube amp is not in your budget)… you want a warm amp… things like Krell, Pass, and CJ come to mind… probably above your budget. Some folks hear can probably recommend some lower budget options.

OP,

It would be really helpful if you could put photos of your system and room under your USERID. There is a place to create your virtual system. This would be really helpful. This would help us to understand the entire situation and make reasonable recommendations.

Folks are trying to be helpful here, but the recommendations are all over the map because there is not enough info to be helpful.

Thanks,

George