SET the best?

To say 845 sounds similar to 300b or any other SET is nonsense. 845 plate voltage nearly 1000V vs 350v with 300B means everything. Power supply 845 massive, 300b baby in comparison. Certainly, transformers extremely important, but these two tubes and amps very different animals. Both 845 amps I've been running for many years sound similar and unlike my 300B or 2a3 I ran some years ago. 845 tube has unique requirements, results is unique sound qualities.

ahh yes, the magisterial  845 tube, has held me facinated for decades, 

Now afforadble, with the newer chinese designs,  still its the weight factor, as you mention. Getting up in age limits mobility.

+ one must consider heat factor, which if I did remain here in New Orleans, in a  small room, get the idea....heater in 100++ degree heat???

= Your *special requirements*

Hi @mozartfan ,

845 tube needs ~10KOhm output transformer that has more narrow bandwidth compared to 3.5K transformer for 300B, 5K transformer for 45 or 2.5K transformer for 2A3 tube. 

So, if you have high sensitive speakers in a small room I don't see any reason for 845 amplifier. Not just because price.

845 not for you, heat, weight, and reliability factors in as well. Heat is enemy of reliability, these things run hot, hot, hot, they have no soft start circuit so wear out tubes more quickly. I wouldn't trust just anyone with nearly 1000v running through these things, not sure I'd trust these rather unknown Chinese 845. Line Magnetic is one of better ones, although I've seen propensity to burn out certain boutique power tubes, which tells me they run them hard.

This is issue I see today with SET in general, some of these guys run higher plate voltage then output tubes can handle, too many instances of premature tube failure. People too often blaming tube manufacturers. Prior to purchasing any SET, I'd research this aspect of that particular amp, know what your in for.

This is issue I see today with SET in general, some of these guys run higher plate voltage then output tubes can handle, too many instances of premature tube failure. People too often blaming tube manufacturers. Prior to purchasing any SET, I'd research this aspect of that particular amp, know what your in for.

Its probably also a good idea to get some idea of what the tube is rated for. For example a 300b in class A1 (A2 an even A3 are possible modes of operation as well) will be good for 7 Watts. A type 45 is 0.75 Watts. When you get stories of greater power, how are they doing that? Is it by using a variant (there's a graphite plate version of the 300b called the 6300b for example) or are they running plate current (class A2 or A3)?

How anyone can say they know what the tube sounds like when the design of the output transformer easily trumps the tube is beyond me. All you can really say is how that tube sounds with that output transformer.