The speaker/amplification wars continue

and let us not  forget, 
Both Einstein and Jung were labeled as *wierdos* by their colleagues. 
~~~~
I Get by with alittle help from my friends, 
I get by with alittle help from my friends
Joe Cocker

It sounds like fun doing this sort of listening shoot outs, but, I hope you don't draw broad conclusions from the results.  At best, you can say this or that particular amp, running a particular set of tubes, in your particular system, and in accord with your particular taste, was the best.  You will have just one set of data in the evaluation of particular approaches to tube amplification.  

From my own experience, I would not conclude that one particular approach is the best.  I own two pushpull amps--one using the 45 tube, the other 349 (i.e., both amps are low-powered), and I have owned and heard many other pushpull amps.  I also own a parallel SET amp (2a3) and have heard many other SET amps, including those that run 211, 845 and other somewhat higher power tubes.  Note that many of the cheaper amps out there running the 211 and 845 do not run them at the very high plate voltages that the tubes are capable of running (a good thing, given how dangerous this can be if not properly constructed).  I have also heard about ten different output transformerless (OTL) amps.  If I were forced to pick favorites, my top picks would be a custom made OTL amp and the pushpull Western Electric 59A amp (runs extremely rare 252 tube).  Among the amps I own, I like the pushpull amp running 349 output tube (essentially a rebuilt Western Electric 133A amp) the most even though it is not nearly as expensive as the parallel SET amp.

At least as important as the basic topology is a whole host of other factors, such as the quality of the parts (particularly output transformers), the basic design choices, and tubes utilized in the amp.  Like anyone else into the tube game, I have my favorites, although this does not necessarily mean that anything else is out of the game.  For example, with respect to tube types in pushpull amps, I tend to like 6L6, KT66, EL34, and EL84 tubes over the likes of 6550, KT88, KT120 and KT150 tubes.  For SET amps, I like 45 and 2A3 tubes over the popular 300B.

There are no outright winners and losers in ANY give aspect of tube amp designs.

Take a breath!!

War!!  
No interest to us pacifists.

@mozartfan While I am also a fan of easy to drive speakers, regardless of your conclusion I really should point something out. The Defy 7 is a rather large amplifier and a 211 SET is not. In a nutshell if you want to know how PP does against SET, to start with maybe both amps should be the same power!

Another way to look at this is if you really want to know the difference between the two, how about eliminate some variables, like make sure both amps in the comparison use the same output tubes at least.

If you want to know weaknesses of SETs here are a few:

1) Because SETs make about 10% distortion at full power, if you really want to hear what they can do the amp should be driving a speaker that is efficient enough that the amp **never** makes more than about 20% of full power. This prevents the higher ordered harmonics from becoming audible; if they become audible it will be perceived as 'dynamics'. IOW the 'dynamic' character of SETs is caused by distortion and nothing else.

2) Obviously the speaker choice must be done carefully as outlined above. The output impedance of any SET is fairly high and the amp does not act as a voltage source, so your speaker choices are limited.


3) The higher the power of the SET the more its bandwidth is limited by the output transformer. This is true of PP too, but isn't really a problem until you are making over about 100 watts, as opposed to about 6 or7 with an SET. This is why the lower powered SETs like the 45s are preferred, but a 45 can only make 0.75 watts!

4) One advantage of SETs is that as you decrease the power the distortion goes down to the point that its unmeasurable. Distortion obscures detail; this is the source of the 'inner detail' that read about in so many SET reviews. But this property isn't limited to SETs, there are a number of PP amplifier topologies that allow this as well. 


5) You'd think an SET would have the simplest signal path but that isn't always the case. There are amplifier designs that have only 1 gain stage; SETs have 2 or 3. In an SET distortion is compounded from one stage of gain to the next in the amplifier. If you have a PP design and in particular if that design is fully balanced from input to output, you can cancel even ordered harmonics in each stage as the signal progresses through the amp. This results in dramatically lower distortion (smoother sound with more detail) even if feedback is not used.

I've yet to see a situation where an SET could sound better than a PP amp **when the variables are more controlled**. Its very safe to say its an antiquated technology which has been sidelined by succeeding arts.