Upgrading from Primaluna

If you run the numbers, the DPHP should have enough power to push your speakers to ear damaging volume cleanly. I used mine with 87dB Dynaudios until I moved on to more efficient speakers. Having options is good though. A solid state amp could be a nice complement to the DPHP, even if it’s more of a lateral move than a clear upgrade. Sorry I don’t have any recommendations though. I went for low power Class A which wouldn’t have enough grunt for your situation. 

I had a HP in a smaller room with power needy speakers and went to a more powerful integrated. For my setup it was just the ticket. More punch and a fuller sound at low volumes too. KT120/150’s would be cheaper than other options despite current tube costs. 
 

Toe in those bad boys. 

I would advise a consultation with Jeff at HD Acoustics. He specializes in small room acoustics. He designed my new listening room and it would be well worth it to have him take a look at your room. Good luck!

Ron

@j-wall 

About room acoustics, with a room only 15' deep, you need some corner bass traps and a lot of diffusers in the back third of the room since you likely have very little space behind your listening position. I agree 100% with the posters emphasizing the need to work with your room and equipment placement first. A sure way to waste less money down the road in fruitless equipment upgrades. Take a look at my room setup. Enjoy the journey.

I went down the high power road for a while.  I had my own personal room heater with 4x 6c33c tubes.  Now with my efficient speakers I'm running 6 wpc of decware and much better sound, my amp makes less heat than my TV, and I can listen or use it for my 2 front channels of AV all day long.  Highly recommend Decware.