Hi Larry,
I have always felt that really good amps, regardless of type, sound great at low volume levels and you really don’t have to crank up the volume to get the juices flowing. A good SET amp will be satisfying at a much lower volume level compared to most solid state amps. The same is true with good pushpull and OTL amps. But, if you are someone who loves to play music at really high volume, a SET may not be your first choice. So, they are often not thought of as being well-suited for loud rock music.
From my own experience, I think SET amps work well with all kinds of music. The only kind of music where I really wished my SET would deliver more power involved large choral pieces without any kind of instrumental accompaniment (e.g., Rachmaninov’s "Vespers"). For some reason, this sort of music is a challenge even when the overall volume is not that high (voices become muddy and the swell in volume is compressed).
I think your experience with SETs and large choral pieces says more about the amplifier and possibly the speakers.
In my comments below, I want to eliminate single driver systems (e.g. Lowther, Fostex, etc.) from this conversation. Single driver systems can flatter small, intimate works, but they get confused when listening to musically dense works (opera, massed chorals, large symphonic, etc.) . In my experience, this can get to the point where you stop listening to this part of your record collection.
I’d like to talk to this low level-listening phenomenon from a system building perspective. One of low power SET amplifiers’ drawbacks is also one of their virtues - that they work best with high efficiency speakers. Of course, this is a virtue that can be exploited by higher power amplifiers as well.
High efficiency speakers (especially horns) in general, have a lower noise floor which contributes to their high resolution at low listening levels, to the point where the experience can be spooky in comparison with your run of the mill, 5-figure, cone and dome system powered by an arc welder. Many electrostats do this as well, but for different reasons.
High efficiency can also benefit high SPL performance as well (ask any pro-sound guy).
Low efficiency means electrical energy is converted into heat, which in this case means the voice coil. This in turn, can affect the crossover, and no high-powered amplifier can compensate for this.
Of course, at the end of the day, preferences are in the context of the perceptual framework of the listener, but (anecdotally), I’ve never heard of someone going back to low efficiency speakers once they’ve had them. It’s a one-way door ;-)
Cheers,
Thom @ Galibier Design
