Tube amp with KEF Reference 1

@justanotherhifiguy Sorry cannot help with the tubes question. However, maybe you can give some feedback on how the KEF R1 sound in your small room? Are you doing anything special to manage the bass?

I used 20 watt Cary CAD 572 SE monoblocks to drive KEF LS50s that have a sensitivity rating of 85 dB, the same as the Ref 1s.  I thought the pairing sounded very good, with a broad and deep soundstage.  I hope to try those amps with my Ref 1s as an alternate to the Ayre VX-5/20.

Have you considered the Masters BoX? I think this would be an excellent match. It’s parallel single ended but has the ability to handle tougher loads without much if any issue. 

I dont think your speakers would be a tough load on a tube amp. The impedance has a bigger impact on them than the sensitivity as it taxes the transformers far more.  

I think perhaps a diraclive minidsp unit with a custom target curve will probably result in a better (and more configurable) sound.