"The way that young people will get into high-end audio is not through streaming: It's through the LP."

When that observation was offered during a recent phone conversation, I wrote it down word for word—not just because I agree with it, but because it was so remarkable: The audio-industry veteran who offered it owns a digital front end worth tens of thousands of dollars, and hasn't owned a turntable for at least a dozen years. Nevertheless, as became clear during the remainder of our conversation, he understands the dynamic that keeps vinyl at the top: a confluence of marketing psychology and genuine sonic goodness.

Class-A amplifiers have a well-deserved reputation for being power guzzlers that run hot enough to burn fingers. They're inherently inefficient because their output devices conduct full current at all times, and much of that current is dissipated as heat—requiring, in the case of class-A solid-state amplifiers, massive heatsinks. This is why class-A amps tend to produce relatively low power, and tend to be heavy and expensive to buy and run. And these days, energy inefficiency is out of fashion.