What to upgrade on $3,000 budget

Get the best amp you can with that 3k it will be the heart of your system from here out. That adcom is your weak link in my opinion. Not that familiar with your preamp but it might be suspect as well. Mediocre amp and pre will always yield mediocre results no matter what your speakers. In fact an integrated amp might be the best bang for the buck at 3k

I agree with upgrading your pre/amp combo to a nice integrated amp.

I think Elizabeth is mistaken as Diamondbacks are excellent, well designed cables that sound amazing (I've had a LOT of cables over many years so they've been vetted) so that's not your problem. I suggest you try a factory upgraded Jolida 502p tube amp which in my experience delivers world class sound at a bargain price, and would provide some "brand synergy" with your preamp. The 3.1s are 89 db so should sound fine with this ballsy 60 watt amp. I fully expect Jolida to reward me for raving about this damn amp...aren't they listening? Come on! jeeze...

Please don't think anything is wrong with your choice of interconnects. Audioquest makes excellent interconnects, speaker cables and power cords. Wolf has a good idea with the Jolida synergy. Use the extra money for some good power cords and then bank the rest for future upgrades.

The Adcom amp is suspect.

For a lot less than 3K you could score a used VTL 85 integrated which would caress your jazz, classical and vocals. Plenty of power and dynamics with great detail and imaging. And the tubes are generic enough to not cost you a fortune to replace. Truly a great piece.