Next Step Advice

What is it that you are not getting ? Or what are you wanting to achieve with the change ?

Good luck .

I would suggest more power from a warmer sounding (colored)
amp for the front three speakers which all should be increased in size and run as large .

I have the Rotel 1095 and would consider this as the minimum for power , for your room , but not very warm sounding . You have a fairly large room to fill with sound , as per your desire .
You will need some large speakers , especially the bass , that can move some large amounts of air . Try not to depend on the subwoofer for your music listening .

On the otherhand , there are two alternatives .
A) If you have the system on the short wall and listening position back aways from there , you could switch the components to the long wall and move your listening position to the opposite long wall . This would effectivly make your listening room smaller and put you closer to the speakers .
B) You could get an integrated amp (tubed) to use for the 2 channel music only listening . But again you would probably need larger front left and right speakers .

The DAC suggestion is worth a shot for the richer aspect .
But I just don't think that the fuller room filling aspects will be achieved with that amp and speaker combination .

Good luck .