SET amp comparable to First Watt SIT 1?

Border Patrol makes a very good 300b SET (as well as 300b PP) amp. Not cheap, but they often have pre-owned units for sale. www.borderpatrol.net. Gary Dewes is very knowledgeable. If you go this route, I strongly recommend Takatsuki 300b tubes.

I agree with Charles and the other comments. My recommendation about Border Patrol was three-fold: (1) it is made in Maryland and therefore repairs are easy (my recent experience with my Ancient Audio taught me that lesson, but that is another story), (2) Gary Dewes makes only 300b amps (SET, PSET, and PP), and (3) he occasionally sells pre-owned and he might be persuaded to let you have an in-home audition. Compared to the 45 and 2a3 SET amps that I tried, I found my 300b amp to be more dependent on the specific 300b tube that is used. Takatsuki trumped Sophia RP (by a lot) that trumped Shuguang BT (also by a lot), etc.

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