I have a pair of M100-2 and I am looking at a new valve amp but wanted to find out the sensitivity of the speakers first. All I can find is a rating of 5W but everywhere else the efficiency is measured in Db. Does anyone know what they are.

I ask because I did have a KT88 amp in the past that worked very well but had higher power output, I then switched to an EL34 amp which wasn't quite loud enough.

By way of comparison I bought an excellent pair of bookshelf speakers the other week at a thrift store - they are unbranded - or the label has fallen off and they use Vifa drivers - the sound they produce is excellent and I could suddenly appreciate things like a wide sounstage and being able to place instruments and voices - it was like a wide wall of sound compared to the M100s. But the M100's produce much more bass and are enjoyable on all types of music. They also sounded louder which made wonder about the sensitivity of them.

Interested in any thoughts as I would have thought with 5 drivers they would be hard to drive.