The Nelson Pass Seminar at CAS6

It's a rare day when famed amplifier designer Nelson Pass leaves his bench to deliver a seminar. It's even rarer when that seminar is geared toward consumers rather than what he calls "specialists." In fact, at the start of his talk, Nelson confessed that after almost 50 years building amplifiers, his CAS seminar was his first ever tailored specifically toward consumers.

Hearing Nelson say that may have caused many of the hundreds of audiophiles in the packed seminar room to breathe a sigh of relief, and inspired hope that they would actually understand what he had to say. It was, after all, quite a diverse crowd. Among those present were any number of admirers, fellow professionals, and family and friends. Spotted among the attendees were San Francisco Symphony recording producer/engineer Jack Vad (whom I didn't see, but who told me he intended to attend), speaker designer and innovator Siegfried Linkwitz, and Nelson's beloved Jack and Jill (dog and wife, respectively, identified by the order they go up the hill rather than by depth of intimacy).

By the time the seminar got underway, Nelson was already at least 15 minutes late in starting. This due to no fault of Nelson's, to be sure. Rather, the issues lay with previous presenters who went overtime, an avid audience so large that it took a good five minutes for everyone piled up in the hallway to snare a seat, and the need to get a computer up and running so that Nelson could project a series of slides on a large screen without hindrance.

The upshot of these unavoidable delays was that moving fast was the order of the day. Just when the man really got going, CAS main man Constantine Soo interrupted him mid-sentence to allow for audience give and take. At that point, Nelson confessed that he was only a tenth of the way through his talk. As he listened attentively, those in the front could see the searing intelligence of his gaze.

Needless to say, what followed thereafter were one or two questions, and a host of slides that passed by so fast that some may have wondered if Nelson had encoded subliminal messages between them (eg, "Pass Labs is the best" and "First Watt über alles'). Some people—maybe lots of people—found themselves left in the dust.

If it's any consolation to those who, like myself, could follow along only so far, it's important to note that even when Nelson addresses a "technical" audience, as he does annually at the Burning Amp DIY event that, this year, is scheduled for October 17 in the South Bay, far more than a few people clap enthusiastically in public before wringing their hands in private because they couldn't follow the entire narrative. If that's a long sentence, you should have heard some of Nelson's.

Thankfully, right at the beginning of the seminar, we all learned something about Nelson Pass: he's a scream. More than a few times, we all cracked up at his quips. I'll see if I can summon forth a few below.

The good news is that Nelson's entire talk will be available online at the First Watt Website soon after you read this. His posting will include many of the graphs he projected at an increasingly fast pace. Many of those, in fact, were created by John Atkinson to accompany Stereophile's reviews, and initially published in the print magazine. It's interesting to note in this regard that while Nelson had intended to remove names of amplifier manufacturers, not wishing to impugn anyone's product, sharp-eyed attendees in the front of the room were able to spot the identifiers in small print off the side of the graphs. That made for some wicked laughs.

What Nelson's posted talk won't say is that he's been building amplifiers since he was 15. Before founding Pass Labs, he co-founded Threshold in 1975, and worked at ESS with Oskar Heil before that. He's been selling amps for over 40 years. His most recent endeavor is First Watt, "a kitchen table company where I can do anything I want."

"I love making amps," he said with a smile.

Then came one of his personal Golden Rules: "After you're finished with it, it's good to give it away." Hence his ongoing involvement with the DIY community. Burning Amp's annual raffles are filled with great, eminently usable stuff that Nelson no longer needs. Those raffles have shrunk in size only because too many selfish people turned around and sold their booty for a profit on EBay.

One of the first slides Nelson projected was of the very first transistor, the solid-state equivalent of the tube. (His talk explains what a tube does.) Invented at Bell Labs in 1947 by Bardeen, Brattain, and Shockley, it was created, in part, from a small paper clip. Several photos were taken of the device, and subsequently autographed by the inventors. Nelson owns one of them.

How much power do you need?
This question occupied Nelson for the first part of his talk. While the biggest amp he ever made output 4kW, and his top-of-the-line creations for Pass Labs output 200 and more watts of power, he demonstrated that the first watt of power is sufficient to convey much of the musical signal, especially through high efficient loudspeakers, eg 95dB-sensitive Tannoys. Hence the name of his spin-off company.

"It's amazing how many people are happy with 10-watt amplifiers," he said. "But it's best to take it home and live with it a month.

"We have a lot of sayings around Pass Labs, and one of them is 'It's entertainment, not dialysis.' It's perfectly legitimate to want an amplifier with a few parts per billion distortion. It's also perfectly OK to have an amplifier with few parts per thousand, or even more. Whatever gives the paying customer the experience he or she is looking for is the thing.

"Usually we find that audiophiles who prefer low power, single-ended, class-A amplifiers prefer far lower volume levels, and often have a taste for simpler material. If this describes you, then you might want to look at some of these sonically colorful amplifiers.

"On the other hand, if you play Berlioz's Symphonie Fantastique at the level experienced by the conductor, you will probably want to explore amplifiers with more power and a more modest distortion figure".

Along the way came Nelson's first reference to this illustrious publication, a quote from one its more infamous covers: the January 1994 issue. "If either of these amplifiers is RIGHT, the other must be WRONG," the issue proclaimed. Some people in the audience immediately greeted this statement as proof that we're all idiots and Stereophile sucks, but Nelson quickly noted that the proclamation's false dichotomy was intentionally tongue-in-cheek. [It was tongue-in-cheek (see the bottom of the page)—John Atkinson, who wrote the text in question,]

There was a point to the cover, he said. "There is no RIGHT amplifier. But there is something that is right for you."

Wilsons, he said, really appreciate a high damping factor. "Those are amps that usually have a lot of hardware and weigh a lot. But don't buy one simply for the damping factor."

OMG, I'm over 1000 words, and I've just begun this report. (For the record, the preliminary copy of Nelson's talk that he sent me, which doesn't include any of his extemporaneous quips, is almost 2700 words long.) Suffice to say that Nelson went on to discuss the nature of feedback, the differences between single-ended and push-pull amplifiers, and the advantages/disadvantages of 2nd order harmonics and those lower and higher.

Nothing was expounded in doctrinaire fashion as he mused over what distortion might be better than other distortion. Along the way came this personal footnote: "I've made lots of money with solid-state, single-ended circuits. It's what I did for the first 5 years at Pass Labs."

Power Cords and more
People have often suggested that Nelson Pass pooh-poohs after-market power cords. On the contrary, he said that he has no problem with them. What bothers him is after-market power cords that are not made to safety standards, and therefore potentially unsafe. The cords he supplies with his amps are heavy gauge—heavy enough to transmit lots of current to his class-A designs—and are certainly safe. When people return his amps for one reason or another, he notes, those power cords rarely return with them. There was some speculation as to their eventual use . . .

Other quotes, quips, and assertions:
"It's my thesis that this current generation is going to grow up and gravitate to higher quality sound. It's going to be different, but I'm not real concerned that tubes and class-A will go away."

"My favorite quote from Marshall McLuhan: 'We take our obsolete technologies and turn them into art.'"

Upon showing a photo of his Beast with a Thousand JFETs," which he sometimes brings to Burning Amp: "I didn't want to call it 2000 JFETs, because there's no drama there." There are actually 2352 JFETs in the thing. It sounds good, too.

On listening methods and blind testing: "I can't tell what's going on using a switcher, especially if a guy is standing over me, but if I put an amplifier in a known system and live with it for a bit, I can form a reliable opinion."

"Class-D is getting better, but it isn't quite there yet. Most people in the High End still prefer 'analog'."

Slides zipped by in Bullet Train fashion after that. It was a choice of either gaze at the slides or scribble in my notepad and wish I knew shorthand. Many of the amps whose graphs Nelson extolled tended to run in the $40,000 range. Read the talk, girls and boys. I've got to take care of three of Jack's distant cousins, as well as myself and my husband, and go for our final walk of the night.

Nelson Pass, you're the best. Love you. And I'm not alone. On August 16, in the early West Coast afternoon, you made several hundred friends in less than an hour. May all your JFETs continue to zing along just fine for decades upon decades to come.

bblilikoi's picture

Nice article, Jason, with just the right mix of appreciation and reportáge. Looking forward to the entire clip once it's up. Garrett

brw's picture

Beautiful ode to a brilliant man. Loved Nelson's quip about Burning Amp: (Paraphrasing) "Your amp should sound the best, or minimally catch fire." Cannot wait to hear him speak without interruption.

kursten's picture

I wish the organizer wouldn't have interrupted Mr. Pass and instead forewent the Q&A portion of the seminar. I'd much rather hear what Mr. Pass has to say than listen to the Q&A. Mr. Pass had obviously spent a lot of time preparing for his talk and was visibly upset when Mr. Soo cut him short.