Thirty years ago, the upstart audio company NAD revolutionized the manufacturing of consumer-electronics components by "internationalizing" the process. Instead of physically making products, NAD hired a project team in one location to design a product that was then built at a sub-contracted factory located elsewhere. The arrangement allowed NAD to go into business with relatively little capital outlay and low overhead. Other companies have since copied this ingenious business model, and, as transportation and communication have improved, doing so has become easier and more efficient. It has brought prices down and quality up—mostly in the low and middle segments of the high-end audio and video markets.
Just in case you didn't know this when you bought the Parasound HCA-3500, it says on the cover of the owner's manual: "Designed in California, USA by John Curl." Described as an "audio design legend," an appellation with which he seems quite uncomfortable, John Curl has certainly been around the audio business longer than most. He's been employed by or has consulted for some of the biggest names in consumer and professional audio—including Harman/Kardon, Ampex, and Mark Levinson—and was the designer of at least two classic products: the Mark Levinson JC-2 preamplifier and his own Vendetta Research phono stage, still considered by many people to be the best phono stage ever built.
We all have biases. The trick is knowing your biases so they don't get in your way. Mine are pretty obvious. I don't like "fussy" gear that demands special care and feeding. I'm lazy—I want to just turn stuff on and begin listening. Perhaps that's why I have a positive bias toward Nelson Pass's designs. They're reliable, untweaky, and usually sound good.
Everyone's going crazy for single-ended power amplifiers. What's the big deal? What is it about these relatively low-powered contraptions that could make everybody so nutso? And has Pass Labs' Nelson Pass completely lost his marbles, selling a 30Wpc amplifier for a price that can buy a high-quality 200Wpc amp? Isn't that 200W amp seven times as loud—and seven times as good—as a 30W amp?
Pass Laboratories' X amplifier series represents the efforts of designer Nelson Pass to prove that simple linear amplifier topologies can be scaled to provide high-quality audio performance at very high power levels. The handsome X1000 monoblock under scrutiny here, the largest and most powerful amp in the Pass stable, makes 1000W into 8 ohms and a mighty 2000W into 4 ohms. The amplifier has no global negative feedback, and only two gain stages: the front-end provides all the voltage gain and feeds a high-current follower stage.
Before the advent of big-screen projection televisions, manhood was measured more conventionally: by the size of one's crate-sized, boat-anchor-heavy, brushed-aluminum-fronted power amplifiers. Those days are long gone.
Over the course of his 30-plus years in high-end audio, Nelson Pass's designs have never been far from the leading edge. In his first Threshold amplifiers he pioneered the use of dynamically adjusting bias and cascode circuitry; then, in the later Stasis models, he switched gears to the simpler approach of pure class-A. All were innovative designs, and among the very best-sounding amps of their time, but were just warmups for what was to come. In 1991, Pass Labs introduced the Aleph 0, a class-A amplifier that was a startling departure from conventional solid-state designs and combined design elements generally thought mutually exclusive: transistors, single-ended operation, and the ability to output 75Wpc into an 8-ohm load. Not surprisingly, the Aleph 0 sounded like nothing else, and became the basis for the widely acclaimed series of Pass Labs amplifiers that evolved over the next decade.
Whereas the Pass Labs preamplifiers are designed by Wayne Colburn, the power amplifiers are the work of company founder and high-end audio veteran Nelson Pass, who even lays out his own circuit boards. The X-model amplifiers, beginning with the X1000 in 1998, were the first implementation of Nelson Pass's patented Supersymmetry topology (see "Nelson Pass on the Patents of Pass"). The XA series, which debuted in 2002, combined Supersymmetry with the single-ended class-A operation of the Aleph series. The XA.5 models offer detail improvements over the XAs.
Audio reviewers are kinda slutty. Not sexually, of course, but in the way we promiscuously go through equipment. Like the most popular girl in school, or Tiger Woods, we have our choice of any hot thing we want, whenever we want it. Heck, reviewers don't even have to pick up equipment at bars or clubs: the stuff is delivered right to our homes. We use the gear for a few months, then send it packing once the next hottie comes over to play in our room.
Man, you've got to watch out for those preconceived notions—they'll kill you every time. For the last several years I've seen Plinius amplifiers at hi-fi shows and—even though I didn't know the first thing about the company or its products—figured that I knew what they were all about. Spotting their brawny façades festooned with feathery heatsinks, I smugly assured myself that they were some kind of antipodean pretender to the muscle-amp throne—Krell or Threshold wannabes.
Nowadays, when most people think of New Zealand, the first things that probably come to mind are the film trilogy The Lord of the Rings, its director, Peter Jackson, or sheep. Certainly, LOTR was a great achievement in film history and, as its auteur, Jackson reaped no small fame for his efforts, as well as multiple Academy Awards and several krillion dollars. The country is also well known as a place where sheep outnumber humans by something like 12 to 1. However, New Zealand is also the source of some very fine audio equipment; both Perreaux and Plinius are proudly headquartered in beautiful, serene, friendly Kiwiland.
When most of us think about the folks who populate the high-end audio industry, we tend to conjure up the designers—the names above the titles, as it were. Or, in many cases, the names that are the titles: Richard Vandersteen, Jim Thiel, Bill Conrad and Lew Johnson, Mike Creek, to name just a few.
Several issues back, I mentioned a major "new wave" of power amplifiers coming along: the Adcom 555, the New York Audio Labs transistor-tube hybrids, and the latest Krells, for example. They demonstrate that major audible improvements are still possible in something as well-explored as the power amplifier. Not only that, some of these products demonstrate that superior performance can be combined with relatively low price.
This is something we don't see too often: an entirely new approach to power amplifier design. As Quad points out in its literature for the 405, class-A operation of transistors provides the lowest distortion, but drastically limits the amount of power an output transistor can deliver without overheating. (Most transistor amps use class-AB output operation, in which each of a pair of power transistors handles part of each signal cycle and shuts down during the other part. Imperfect synchronism between the two halves causes the familiar "crossover distortion," which accounts for most solid-state sound. In class-A operation, each output transistor draws current though the entirety of each signal cycle, eliminating the crossover transition but doubling the amount of time current is drawn, and thus tending to cause the transistor to heat up more.)