Before Helmut Baumgartner and I start moving the M500s from my listening room to the photo studio, we briefly listen to the fourth movement of the Symphonie Fantastique with the Utah Symphony conducted by Varujan Kojian. I've probably never heard this Reference Recording copy so open and airy: Already during the first few seconds, the enormous spatial depth is impressive, despite the volume is at a very low level here, while the explosive dynamics add highlights to the exceptionally transparent sonic image. The kettledrums towards the end of the piece evolve exceptionally fast, controlled and yet extremely powerful. No other amplifier that I came across so far has managed to master this very demanding piece so sovereignly. Helmut Baumgartner found even more prosaic words for it: "I've never heard such musical power amplifiers with so much power." This is a conclusion I fully share.