Hey Warren,
I own a MasterSound Reference 845 Integrated Amp. Pure Class A..40WPC, running with 4 KR 845, 2 Mullard 12AUT, and 2 Emperex Holland 7119. She is gorgeous and dead on pace with speed, soundstage is dynamically amazing , true timbre, strong tight bass...best amp i ever owned..well except for the 845 Monoblocks..that's next on my list.
Previously i have owned... Antique Sound Lab AQ1001DT, Synthesis Nimis, and Cary SLA-70B Signature...these were ok and fun to roll tubes around with..sold all of these and got the Mastersound...best move i ever made in the audiophile department.
Hope that helps. Best of luck to you.
SD