2a3 ?

I have been told by someone who should know that a 2a3 is, essentially, two 45s in one enclosure. When I used to own a 300B amp I was always a bit puzzled about the reverence shown to the 2a3. I wondered why praise of the 300B was not universal? Why was it often considered as "behind" the 2a3 and the 45?

Then I got to hear the 45. The midrange emphasis of the 300B was clear, as was the more extended frequency response of the 45. The tone and inner detail of the 45 was breathtaking (my room, my speakers, my listening preferences, YMMV). 

So, not exactly a response to the OPs original question, but I wanted to add my .02...

Nearly pulled the trigger on 45 amps as well but concerned

about availability/durability/reliability of tubes that haven't been manufactured in decades. I have little tolerance for equipment that

may have questionable reliability.

I love the 2a3 tube I have a pair of George Wright monos myself and love them. Clean and clear sounding but still natural and warm they drive my Audio Note AN-J's perfectly.

Very much looking forward to reading people’s experiences. I recently picked up a Sony TC500a R2R portable player. Bought it to harvest the transformers and the speaker drivers. 
 

Trying to figure out if I want to build a 1626, 45 or 2A3 with the transformers. 
 

leaning towards the 2A3/45 option. 
 

When my local Audio Note desler first set up the ultra expensive AN-E SEC, he chose Audio Note’s Kageki (parallel SET 2a3 amp).  He used the same amp when setting up the top AN-J model.  The sound of both speakers was magnificent.

i own the Kageki and like it, although these days I run my pushpull 349 amp.