SET amp comparable to First Watt SIT 1?

You may have already considered a Line Magnetic  product, if not here is a couple for your consideration.
There are many reviews on line, that you should be able to get an idea of the characteristics of each amp.

http://www.toneimports.com/lmaudio/210ia.html
http://www.toneimports.com/lmaudio/219ia.html
http://www.emissionlabs.com/html/products/products.htm
http://sophiaelectric.com/

Phil, Charles, et al.

I am a fan of the Takatsukis, but have not heard the Balloon KR 300b. That said, I can attest to the longevity of the Takatsukis. I have been using the same pair for about 5 years without any issues. I was fortunate to source a couple of pairs from Japan at a reasonable cost when they were first released. I have also found the dealers in Japan to be very accommodating - but the current price is steep and not negotiable.

While we tend to talk about output tubes and their variations, recently I have been trying different 6922/7308/etc. driver tubes and have been impressed by the impact - at least in my amplifier (custom made Ancient Audio 300b SET). I am currently using a carefully matched pair of Amperex white label, PQ shield 6922s. The difference is not subtle.

Gary

Gary,
You and I go back quite far with our mutual admiration of the superb Takatsuki. I have come to suspect my amplifier may be a little tough on some 300b tubes. In the past 4 1/2 years I had to replaced 2 individual Takasuki tubes (done without any hassle per my Japanese source AMS Tram). The EML XLS is a heavy duty constructed 300b and seems very well suited in my amplifier. Reports say this durable 300b has a life span capacity of 40,000 hours ( similar to the discontinued AVVT SL 32).

A friend of mine has a very upscale and accurate tube tester. He tested my EMLs when they were brand new 3 1/2 years ago. He recently tested them and they measure "exactly" the same and they are used frequently in my system. This is a very rugged tube that also sounds superb in my amplifier. The Elrog 300b is sublime in sound quality but too fragile for my particular amplifier.
Charles

I don’t want to bother those people with my ignorant questions,

@tmare, ignorant questions are the best ones! Never, ever worry if you are bothering the manufacturer by asking them; that should be part of why they are there!! Otherwise you might want to rethink how much support you're going to get.

I have owned OTL amps and like many of their characteristics, but I've never heard one, especially using massed output tubes, that has the sheer transparency, speed, holistic tone and spatial precision of Audion SET overall, and especially the Golden Dream monoblocks

Funny- my experience has been the opposite. Our amps have a risetime in the output section of 600V/mS, where the typical SET might be about 10V/mS. So its not only audible but measurable. Usually that's a pretty good indication that its actually real. In addition to the speed, our amps have more bandwidth as well.

Now what is going on with a specific amp on a specific speaker might really affect the outcome of your perceptions (for example a low impedance at high frequencies that one amp can drive while the other can't might make that latter seem slower even though its not). So its a good idea when doing comparisons to make sure that both amps, whatever they are, are in proper operating condition and are also a reasonable match for the speaker being used (that is, if you really want to find out what the differences are between the amps being compared).

Yup, true. I've used OTL and SET on a very wide variety of speakers under optimal conditions for both amps. I'll put my statement cited in further perspective:

40, 30, 20 years ago, I would have (and did) recommend and own OTL tube amps for maximum transparency, speed and musicality, used with appropriate speakers, including over all the SET amps I'd gotten my hands on up to 1999. That's when I first happened upon an Audion SET 300B amp. And then further put original KR Enterprises 300Bs and well-chosen NOS input and driver tubes in it. With the emergence of objective high efficiency speakers (ala Zu) in the 2000s, the higher power of OTL became less necessary.

The Atmasphere amps are certainly transparent and fast, and I don't dispute the rise time measurements you site for them. But Audion SET amps are uniquely fast and transparent examples of that topology and I hear them as a notch above OTL.

Phil