Question about set amps and low sensitivity spkrs

The short answer is yes you can use the SET with your B&W without doing damage (though your tubes will work harder than they would with a different speaker, but that isn't damge, just wearing out tube life), but the specs suggest a match far from ideal. Like others have said, the sensitivity per se is not too much of a problem at most listening levels, though measurements I saw in audioXpress suggest the real sensitivity is really closer to 88db. The real problem is that speaker has very large phase angles (large swings in impedance) which are not so hot for hot for SETs or tubes generally (why many B&W speakers don't always match well with many tube amps). So, you should be fine for now, but if you love the amp, you do need a different speaker to hear it at its best. With 18 watts I would look for 92db minimum and smooth 8ohm or higher impedance curves.

Only problem with the 4ohm tap is that you are going to drop the wattage quite a bit - I think.

Tvad, I thought that was they way SS usually works, but not tubes (but I'm no expert).I know when I owned the RM10 Roger Modjeski said I would loose power if I used the 4 ohm tap versus the 8 ohm, but there were advantages in terms of dampening and distortion. By the way Mbleming, what amp are you using?

Newbee, I agree that a tube amp generally puts out the same power into different impedance loads of the speaker, but I'm talking about the output taps (4ohm, 8ohm etc.) of the amplifier. I thought that into the same loads, the 4ohm tap and the 8 ohm taps put out different power. That was my understanding with the Music Reference gear (I think he said a 3db drop using the 4ohm tap into a 8ohm load versus the 8 ohm tap); but I could be wrong.