I owned a D5 for 4 years. On three different occasions I auditioned the SE version and came away unimpressed when compared to my D5 with Siemens or Amperex 7308s plugged in. To my ears, my D5 was livelier sounding. The SE sounded dark by comparison. The SE had tighter bass and perhaps a bit more detail, if I remember correctly. I do remember I had a strong preference for the standard D5 with top notch tubes.