Totally Tubular

The first jazz I ever heard was amplified by vacuum tubes. I remember Louis Armstrong and Spike Jones coming through loud and clear via our family’s old black and white television. In those days, you couldn’t listen to recorded or broadcast music that was not amplified by what enthusiasts now call burning bottles.

Even our 1954 Ford Country Sedan nine-passenger wagon had a tube-powered radio-I always became impatient waiting for it to warm up before tuning into WKY in Oklahoma City-and I fondly recall peeking through the grille to watch the warm glow of the tubes as they pumped out Ray Charles and Buck Owens.

These classic, some say organic, circuits were quickly replaced beginning in the early ’60s with the advent of the marvel of the age, the transistor, and most thought tubes would fade into the sunset like so many glass Hopalong Cassidys, never to be seen again. (Quietly, the Defense Department continued to use tubes in critical areas in order to avoid silicon’s fatal sensitivity to nuclear blasts.)

But unbeknownst to the public at large, who had been led to believe that modern solid state was the only convenient and reliable-hell, the only-potent way to listen to music, a covey of tube adherents stuck to their guns, happily grooving along to the Sonnys (Stitt and Rollins), Charles Mingus, Bud Powell in warm, soothing splendor. They kept their ecstasy a secret for some time: they knew that solid state, even when the acknowledged early edges were sanded down, would never better the smooth, musical, natural sound of a good tube design. They swore, in fact, that solid state would typically sound worse because transistors do funny things to the signal that, in a sense, take the life out of the music.

Finally, beginning in Minneapolis, the secret came slowly out of the bag. In 1970, William Johnson started a company called Audio Research, one of the first high-end audio manufacturers. Its primary products were unheard of in 1970: newly designed and built tube amplifiers and preamplifiers that aimed at state-of-the-art musical performance, not stressing the new technology bells-and-whistles approach pushed by the marketing guys along the Sansui/Kenwood axis so dominant at the time.

None of this should come as a surprise to guitar players who have recognized the quality of tube amplification all along. As time went on, more and more audiophiles also became reacquainted with, or were introduced to, the joys of listening to music through a system fired by glowing glass.

“If you prefer the sound of solid state over tubes, you’re deaf, especially if you are into jazz,” says Joe Roberts, noted tube guru and attitudinally heavy publisher of Sound Practices, one of the most influential tube ‘zines around. “There is a lot of lip service paid to solid state as being more accurate. Yeah, in strict technical terms, tubes might be higher in distortion, but to the ear, they sound more natural and less distorted. This is because tubes have a preponderance of warm, rich-sounding, even-order harmonics [distortion], which are more musical sounding. Transistors create odd-order distortions which sound harsh or edgy to the ear.”

Roberts goes on, “In the audio enthusiast market [meaning systems designed purely for music reproduction, not surround sound], probably 85% of the equipment made now is tube gear. Solid-state manufacturers seem to be catering primarily to the home-theater consumer. And the tube stuff is getting more esoteric all the time.”

Roberts is intimately familiar with this increasing esoterica since Sound Practices was instrumental in the resurgence of interest in very low-powered (three to 20 watts), single-ended amplifier designs. Most common tube amplifier designs are push-pull amps, meaning that two tubes work in tandem to create the up and down cycle of the sound wave form. And the output transformer-the last stop in the amp before the signal goes to the speaker-has to deal with these two independent signals, combining them, in a sense, back into one unified sound wave; the result is that the transformer acts something like a switch being flipped on and off very quickly, adding unwanted harshness to the sound. In single-ended amps, the wave form is created by a single tube, simplifying the circuit and creating a more linear, less choppy sound because the final output transformer is always on, producing a cleaner sound and allows the transformer to deliver more juice to the speaker. But power ratings tend to be low because only one output tube is utilized.

“Power ratings are immaterial,” Roberts proclaims. “Some smaller amps sound more powerful than larger push-pull amps and they are faster, more responsive, more colorful. They just sound more like live music.”

Gordon Rankin, who designs and personally builds every piece of equipment for his world-renowned tube-based electronics company, Wavelength Audio, agrees. “Jazz listeners will love single-ended amps because of their musicality. And, though it is now the strongest segment of the tube-amp industry, like jazz, it has suffered-in the beginning audio magazines hated it because they didn’t understand how such low-powered amps could be taken seriously. Now they love it.

“The beauty of tubes is the simplicity of the design,” Rankin declares. “You use fewer tubes than transistors, and tubes are more linear than transistors. A tube is simply a more realistic device when it comes to music.” (Linearity means the frequency response is effectively flat, or linear, from start to finish, without any significant rises or dips along the way.)

And Rankin should know. His family once owned the Reynolds Instrument Company, a longtime leader in brass instrument production, and he grew up learning to play over a dozen instruments, including a sax his father built for him. “I think I have more appreciation for what things sound like since I’ve played everything from orchestral to rock and know the euphoria of music.”

He uses his knowledge of music to fine-tune the designs of his amplifiers and preamps that have won acclaim around the globe for their ability to reproduce music with startling realism. I was lucky enough to experience his craft a couple of times and I must say that I don’t think I have heard a more present, more palpable, more exciting sound from any stereo system. For a couple of weeks I lived with a pair of his Cardinal XS single-ended triode mono-block amps that produce an amazingly powerful 10 watts for $7,500. They ain’t much to look at from a high-design standpoint, but they deliver music and fun by the boxcar!

When I had these connected, I was constantly looking around the room to see where the musicians were hiding. It really was that real. I almost turned to a life of crime in lieu of returning them to Wavelength. Earlier this year I auditioned his Triton Signature amps, which helped convert me to the Patricia Barber cult when I listened to her sing through them. These 15-watt, $10,000 beauties sculpted her right there in the hotel suite, as enchantingly, faithfully and more enjoyably than could Michelangelo. I was hooked on Barber and sold on single-ended amps!

There is one caveat, however, when considering relatively low-powered equipment: you need to pay attention to the efficiency, rated by the sensitivity level, of your speakers. Typically you should have speakers that boast a sensitivity of 90db or greater, roughly signifying that one watt of power can produce 90 decibels or more of sound, depending on the rating. Other factors are involved as well, but use this as a general guideline-and consult with your dealer, as always!

Today’s sound-equipment market is flooded with tube equipment. It’s no longer difficult to locate reliable, high-quality designs utilizing tubes; any reputable dealer around the country carries at least one line, if not several. In fact, there are more companies producing tube equipment today than at any time in history-imagine that in these days of MP3 players inside wristwatches!

And the tube supply? “There are more tubes made today than during the ’50s,” says Rankin, “and today’s tubes are better. With today’s technology, everything is easier to make. Remember, your computer’s CRT uses the same parts and technology as a vacuum tube for audio, so manufacturing will never be a problem.

“The current interest in tubes is not a revival; most of the stuff going on today is new, it has never been done before. In fact, there are new tube designs coming onto the market all the time. Since around 1995, there have been countless new tubes introduced and equipment designers snap these up as soon as they come out and create new amps to take advantage of improved, often more powerful, more rugged tubes.”

In regard to shopping, Rankin has a few suggestions. “Go out and listen. Don’t buy something on the Internet, for example, that you have never heard. Also, don’t buy a tube amp of any design that does not use a tube rectifier. Jazz lovers will suffer with the sound of a nontube rectifier, so make sure you discuss that with your dealer before you buy.”

Where to start? Well, take Rankin’s advice and go listen. You might have to travel a bit, maybe to a large or larger city nearby, but the equipment should be fairly easy to locate. Following are some names to look out for.

Perhaps the most widely available manufacturer is Audio Research, partly because they have been at it for over 30 years, and partly because its stuff is designed to last, and dealers really appreciate that reliability. Much of the company’s original equipment is still in use and many models have become collector’s items. Audio Research produces solid, very good sounding amps, preamps and digital-to-analog converters (yes, with tubes) that will last a lifetime. You absolutely cannot go wrong with these guys.

Quad of England actually has a longer history working with “valve” (British lingo for tube) gear than Audio Research-its ’50s-era amps are still fondly remembered, and in use, by aficionados. Though primarily known today for its landmark electrostatic speakers, Quad has recently introduced a new preamp/amp setup (not sold separately), the Quad II-Forty ($6,499.99), with valves at the heart. Quad has opted for a visually stunning retro design that I just love. Oh, and the sound is spectacular-they have been filling my home with silky smooth music for the last couple of months as I’ve prepped for this column and I can honestly say that they are as good a push-pull amp as I’ve heard. And since the build quality is first rate, utilizing premium components and a hand-wired circuit, these babies will still be cooking 30 years from now with just a change of tubes every few years. I can’t wait to hear them with the critically acclaimed Quad 989 electrostatic speakers, something I hope to do in the near future. Quad is definitely a name to seek out for stunning sound with reliability to match.

Another long-time manufacturer devoted primarily to tube gear is Conrad-Johnson. The company is well known for simple designs that endure also, but with a slightly softer, some say “tubier,” sound than Audio Research. Selecting this kind of equipment really depends greatly on personal taste-it does not all sound the same, each manufacturer has a distinct personality-so, all the more reason to get out and audition.

A newcomer, Rogue Audio, has already proven to be a winner. Owner and principal designer Mark O’Brien has put together a line of well-constructed amps and preamps that utilize premium parts and not only sound good, but look good. I listened to his “statement” amps, the M-120 Monoblocks ($2,695 per pair) and was impressed by the control they had over the speakers: nice, tight bass that extended low enough to rock the room, but most importantly, they offered that rich tube midrange so important to jazz, whether vocals or instrumental, since most of the important information in this music occurs in the mids.

One more new name on the tube front is Legend Audio Design in Berkeley, Calif. When I heard its system-Starlet integrated amp ($2,995) and Legend speakers ($3,995/pair)-at CES in Las Vegas, I was blown away by the lifelike sound. Before I entered the room where this system was cranked up, I could have sworn there was a live drummer playing, the sound was that “present” and dynamic.

Other lines to check out for their quality, mostly push-pull, designs include Manley, Sonic Frontiers, Red Rose Music (jazzer Mark Levinson’s newest venture), Quicksilver, Valve Amplification Company (VAC), Vacuum Tube Logic (VTL), Atma-Sphere and Convergent Audio Technology, just to name a few.

The single-ended field is getting more crowded by the day, but there are many newcomers so make sure any lines you investigate have a good track record when it comes to reliability and design. One such company is Art Audio, another English concern with strong ties to the States. They offer a full range of products starting around $3,800 and running to over $11,000 for their top-of-the line Jota monoblocks. Their 13-watt per channel Diavolo ($5,995) has been in my living room for a while, and it is, in true single-ended fashion, stunning. When I first plugged this sucker into my system, my son, who was upstairs, screamed out, “Damn, that sounds great. I’ve got goose bumps, it sounds so real.” If that is not praise, I don’t know what is.

This very morning, my next-door neighbor asked me if I played the piano because he had been hearing something that sounded like a live piano coming from my house; in fact, it was Keith Jarrett pouring out of my windows courtesy of the Diavolo. The bass on this amp is tight, focused and extends well below what I am used to, as witnessed by the opening acoustic bass work by Danny Thompson on the wonderful new recording Spirit of the Century (Real World), by the Five Blind Boys of Alabama. But, as mentioned above, it is the midrange that creates the startling realism: Holly Cole was in the house last night singing “Que Sera” from her live It Happened One Night (Metro Blue) and the goose bumps made another appearance; Jack DeJohnette’s impressive drum work with the Keith Jarrett Standards Trio has never sounded so exciting; and the Pat Metheny Trio was truly live at Chez Quinn with the Diavolo pushing my JM Labs speakers.

As for other single-ended amps, in addition to Rankin’s Wavelength products and Art Audio, check out Audio Note (the pure silver-wired Japanese models can run nearly a hundred grand, so watch out!) and Loth-X Audio ($80,000 gets you their silver-wired, battery-powered unit!).

In hindsight, it seems like I am discussing a lot of very expensive equipment in this column. Well, it’s all relative isn’t it? If you are a regular JazzTimes reader, then you obviously take your music seriously, so an investment in electronics that will present your favorite sides in three-dimensional sound in your living room and that can last a lifetime should be well worth considering. But don’t let prices scare you; a very satisfying tube setup can be had for less than $3,000 if you shop around-just remember to find a dealer you can trust.

When you get those bottles burning in a darkened room, glass of nice wine in hand, and invite someone like Bill Evans, Betty Carter or Charles Lloyd for an up-front and personal, nearly holographic appearance, you’ll know you’ve done the right thing.

Originally Published October 1, 2001