SET for Orchestral , Big Band etc.

not agree with Jaybo, sorry. I have a set amp (master sound 845) driving my SAP J2001mkII horn/hybrid speakers. Most orchestra works sound wonderful with fast, accurate and natural music. Set amp can drive big orchestra easy, depends on matching equipments.
Patricia Barber and stuff like.... Patrica Barber, sounds fine with most of system, no need for high end system.

A quality SET does not sound mushy or bloated; it simply has a bit less "slam" than a comparable push/pull design. The SET has a bit better/lusher midrange than a push/pull.

If I wanted a quality tube amp making at least 20 watts with good dynamics the 300b push/pull interstage coupled dual monaural design would be at the top of the list. A 211 based SET designed to run up to 30 watts would also be on the list but it is more expensive to build than the push/pull due to transformer requirements.

Getting satisfaction from listening to large-scale music through SET amplification is not a function of the amplifier alone, but instead the combination of speakers + amp. On my 101 db/w/m Zu Definitions and Zu Druids, my various SET amps can produce explosive dynamics and project convincing energy along with tonality into the rooms the two systems operate.

As others have noted, an 845 or 211-based amp is a great way to get SET focus and intimacy with scale. 25w per channel goes a long way in a 101 db/w/m speaker. Most 300B amps sound progressively less incisive pushing complex, large-scale music at convincing domestic SPLs, the signature bass bloom and rich midrange thickening articulation. But as usual, this is a matter of cost. There are some highly evolved 300B amp designs at high prices that manage to tame the excesses of typical 300B sound to make it quite objective yet richly expressive at the same time. So getting what you want is also a function of finances.

If you are playing in the $6000+ region for SET amplification, you can get equally credible but different signatures from 300B, 845, 211 amps. But if you are considering an amplification allocation under $3500, don't let purist sentiments keep you from considering various single-ended KT88 options. They're not triode, to be sure, but some are quite competitive. In between, especially if you consider used amps, it can go either way. For instance, there is on Audiogon right now a used Audiopax Stereo 88 power amp (no, it's not mine). This is a single-ended KT88 that delivers 15/15watts of world-class clarity and on something like the Zu speakers is fully capable of impactful sound from an orchestral recording. The only triodes are in the input section. I think you can find that one for around $5K. You can also find Parallel SET offerings that retain single-ended attributes with more punch than a single tube outputting single-digit watts can muster.

But I'd have no trouble going back to my 7/7w 300B integrated even on symphonic music, if some combination of circumstances suggested I should.

Phil

Yes, buy 103 db or higher efficiency speakers and a 300b SET and blast away. There is much variation in the quality of such speakers and amps. Listen before you buy.

I currently run my 99 db/w efficient speakers with a SET amp using parallel 2a3s. That is plenty enough power. While I like the sound of this amp very much, I also get pretty good results with pushpull triode amps as well. I know that there are a lot of people who will say that only a SET can deliver certain desirable qualities, but, since everything is a matter of finding acceptable compromises, if you don't have suitable speakers, if you prefer more control in the lower bass, etc., you should also look at good pushpull alternatives.

I have a 45-based pushpull amp that I keep as a backup (I may use it to bi-amp my system some day. It is not a shabby alternative to my SET amp.