Recommendations Amp, DAC for Kef R900


Looking for advice on Amp’s and DAC’s for my new Kef R900 speakers.  Currently running them with only a Yamaha A-S801 amp, and I’m afraid I may be under powering the speakers, and may damage them (although I have not heard any clipping yet).

I am using a Sonos Connect - listen to mostly Tidal and Spotify, both through my iPhone, and the USB port on amp.  Listen to large variety of music, but mostly to Alternative, Classic Rock, and Reggae.  I will also be attaching TV to system soon, but will use the system 99% of the time for just music. Unless I start watching a lot of movies, I don’t plan on adding a sub. Have the system setup in my fairly large, basement. 

I want to purchase a very nice system, but only want to purchase in steps.  When finished I would like a good 2ch integrated Amp, and DAC system, but am wondering if I should get separate Amp/Pe-Amp.  Would I notice a big difference listening to streaming?  I was hoping to use the Yamaha as the Pre-Amp, and buy a nice Amp next, but I believe that this is not an option.  I want to buy used, budget of $2k for Amp, $1.5k for DAC, but I am flexible.


vaporcloud
The R900 are pretty efficient @ 90dB. The Yamaha is 100 wpc, which is more than sufficient to drive those speakers. If your long-term goal is going full integrated HT, why invest in an integrated? Go with a multi-channel amp and pre-pro or top-shelf HT receiver. Assuming adding the TV is a smart TV, you'll need HDMI in/out, which the A-S801 does not have.
Think about a used Lyngdorf 2170. Everything you need in one and sounds fantastic. 
Thanks for the responses.

The Yamaha seems to be working ok, but I would like to have best sound possible from the Kef's.

Both the Kinki and Lyngdorf look nice... but it looks like it may be difficult to find one used!!  Any suggestions for something that I could buy used?
Maritime51, So was the problem with your KEF’s not the speakers after all?  This new amp fixed your speaker complaint.  
Component matching isn’t always simple.