Music Reference amps are amazing in the power they deliver while simultaneously giving great tube life. Read the reviews and discussions here and eslewhere, you'll find it's true across all of Roger's designs.
I have an original RM-9. Roger went through it a couple of years ago, when it was 17 years old and still running the original RAM tubes. He upgraded a few electrolytics and installed nicer biding posts. I reinstalled the original tubes and they still sound great but decided while the amp was in Roger's care it was an opportunity to try the RAM KT88s. They sound amazing.
I have an original RM-9. Roger went through it a couple of years ago, when it was 17 years old and still running the original RAM tubes. He upgraded a few electrolytics and installed nicer biding posts. I reinstalled the original tubes and they still sound great but decided while the amp was in Roger's care it was an opportunity to try the RAM KT88s. They sound amazing.