Solid State Power Amp Reviews

The Aleph Null, or 0, represents Nelson Pass's maiden product under the Pass Laboratories banner. When he left Threshold several years ago, Pass had the luxury of starting over with a clean slate, and decided immediately that he wanted to design a single-ended MOSFET amp. The result is aptly named after Georg Cantor's first transfinite number: Aleph Null, the gateway to higher-order infinities. Just as Cantor's transfinite mathematics stretched minds with its novel conceptual view of the infinite, the Pass Aleph 0 tantalizes the imagination with a new dimension in the future of solid-state amplification: a single-ended output stage.

I own and enjoy loudspeakers from seemingly opposite ends of the audiophile spectrum: I'm a huge fan of minimally efficient yet otherwise overachieving flat-panel designs, such as my Magnepan LRS speakers. Yet I'm just as smitten with another, equally outside-the-norm alternative: high-sensitivity full-range loudspeakers, such as my Zu Omens—especially when driven by tube electronics. It's an ongoing yin and yang that keeps my home system in a constant state of flux: Alternating between loudspeakers that use such different technologies, while maintaining relatively optimal positioning for each, is a bit daunting.

My writing desk looks out over a large garden with chickens, bees, and feral cats. My chair sits only six feet from loudspeakers, playing softly on my left. Between the speakers sits whatever painting I am working on. That painting hangs no more than 10 feet from the oscilloscope and drill press in my kitchen. Best of all, my desk is only six feet from squadrons of ravenous sparrows attacking the suet cage on the fence outside my window.

What's the point of reviewing a pair of monoblock amplifiers that costs more than most people spend on two or even several cars— and far more than most audiophiles spend on an entire music system? That's a good question. Another is: Why should I write this review when, just seven years ago, I reviewed a pair of darTZeel monoblocks that look exactly like this new pair?

I realize that products such as the darTZeel NHB-468 ($170,000/pair) are for the very few, but the very few include far more people throughout the world than you may realize— people who can afford such costly audio products and who do buy them. I know, because in my travels I've met a lot of them, and they deserve to read reviews of products they're considering buying—things most of us can only dream of owning.

Class-D audio amplifiers: What's the argument for them? Class-A audio amplifiers: What's the argument against them? Class-AB amplifiers: Why does everybody make them? Each of these amplifier output architectures has strengths and weaknesses. Each will interface more or less successfully with a given loudspeaker in a given room. Each has a distinctive sonic signature. Consequently, as knowledgeable audiophiles with a laundry list of system-building goals, we are required to choose the amplifier type that best suits our speakers, our room, and our individual musical-aesthetic predilections.

CH Precision's massive, versatile, technologically sophisticated, 165 lb M1.1 power amplifier ($54,000 configured for stereo) can easily crush your foot if you're not careful when installing it. But the more important consideration is this: Can this cool gray techno-square sing and dance without stepping on its own feet?