Tube amp for KEF Reference 3s

Hi Everyone,

  Long time Audiogoner but this is my first post here.  I am looking for some suggestions regarding amplification for my KEF Reference 3s.  Currently I have a Modwright KWI 200 with built-in DAC which I like a lot, but wonder if the KEFs would benefit from a high-quality tube amp.  I would like to go for a high-end amp like a VAC or Air Tight but would prefer "testing the waters" first by trying a tube amp in my system.  I primarily listen to Tidal streamed through a Audalic Aries into the Modwright and analog through a VPI Traveler/Musical Surroundings Nova II.  I have a small listing area (my office) which is approximately 12 x 16 and I have some GIK acoustic panels in the corners and along my back wall.  If anyone has suggestions as to a "low-priced" tube amp that might give the KEFs a somewhat warmer sound I'd be willing to purchase used and then move up the chain to a higher-end amp if things work out.  Thanks in advance for your advice.