Silverline Sonatina's or Coincident Victory...

I have used a 2A3 SET amp with Sonatinas and you won't get low growling bass. You do get realistic bass as long as your room isn't too big and your choice of music is not too demanding .... I found the pair very seductive and refined ... no loud rock or full orchestra ... jazz, string quartets and the like ...

The efficiency is obtained with better magnets "motors", cabinet loading and design. The efficiency is not magic it is based on sound engineering. I have listened to the Silverline line only briefly, so I am not a good judge. I am very familiar with the Coincidents. The victory needs at least 300hrs, Mr blume says they need at least 400hrs before you can really listen to the speaker. I own the Total Victory, picture a Victory with four 8 inch woofers on the side and taller. I have listened to the Victory, it is a wonderfull speakers specially with tubes. I heard it with a 300b's, about 8 watts. I am sure they will sound good with a 2A3, but I think a little more power would be needed for a full orchestra at room filling levels.

In a smaller room and at lower volume levels it should suffice. This comes from someone who has no expirience with 2A3 amps. So take it with a grain of salt.

Good luck in your search.