What is the best 2A3 SET Amplifier?

Yes, you are absolutely right. The good old US did created the 2A3/300B and even the SET amp but those are accient history........ But they also the first one to abandon it.........
Back in the 1920 or so, all those hard-working Bell Lab engineers/scientists are the true pioneer/inventors in this field. They are creating a whole new technology. I don't see there are any corelation between them and the current designers or copiers.
Please look underneath their SET amp if you know what you are looking at. Poor parts, poor circuit design and poorly design tiny output transformer(mass produced in Taiwan). It doesn't take a rocket scientist to figure out how it sounds.
The Japanese are constantly refining the SET amp since the mid 60's. French are doing the same since the mid 70's. And the US are doing it recently(early 90's). Don't you think they are just a baby!
Thanks for reminding me to crawl back to my hole.

May be you should go out from your hole more often.

What are the dimensions of these holes? Do they have good acoustic properties? Perhaps I should abandon my listening room and get me a hole.

I own a pair of Audio Note UK Neiro 2A3 PSE monoblocks and those are, without a doubt, the best amps I have ever heard! Prior to getting these amps, my favorite was the Kondo-made Neiro. The new UK versions better the Kondo product with greater resolution, tonal purity, dynamics, vocal clarity, soundstage width and depth, and no Kondo sugar coating.

The new UK Neiro monoblocks also have more gain than the Kondo Neiro, so there is no immediate need for an active linestage. I feed my Neiros from an Audio Synthesis Passion Ultimate and the combo is great!

The amps come stock with copper foil capacitors and I just upgraded them to the new silver foil versions. Wow! Even more clarity, definition, space, you name it!

If you can afford it, you won't go wrong with these amps!

I agree with Edle that Audio Note makes very good SET amps, but not everyone can afford them. I agree with clueless, unless you know for sure you can live with a 2a3 for all the types of music you listen to, I would buy one of the consonance or bottlehead amp kits over the Audio Note. I also believe there is no 'best' it is all relative to the rest of your system, musical tastes and budget IMHO.

I beg to differ with the assessment of "Made in USA" amps being "poor design, low parts quality". My Moth s45 uses excellant "stock" parts INCLUDING Electra-Print OUTPUT TRANSFORMERS that were designed specifically for this particular amp. Speaking of quality iron, Welborne uses Magnaquest transformers and yet you still feel that equates "low parts quality" - interesting.