Yamamoto A-08s and preamp CA-04

That A-O8s SE45 amp is a mere 1.75 wpc! It was reviewed some years ago by Stereophile (should be in their archives). I have a similar SE amp - two-channel 45/6C6's built on a Dyna ST70 chassis by Will Vincent. Requires a 100db sensitivity speaker, like your Avantgarde's. I have Klipsch Heresy's. Excellent sound with the right speaker match!

Joe Roberts of Sound Practices (look it up - the best journal for DIY tube enthusiasts!) thought that the 45 was the best sounding triode for SE use! He also liked the 71A (half the power of the 45). I bought a pair of Heresy's to use with my SE 45 and 2A3 amps.