The Great Tube Debate

I LOOK FORWARD TO READ ing Invention & Technology , but when I openec the most recent issue, I knew I’d be in trouble. I agree with guitarists that tube-sound distortion is what they’re after (“The Tube Is Dead. Long Live the Tube,” by Mark Wolverton, Fall 2002), but I wince when people say they prefer tube sound over solid state when it concerns the reproduction, not production, of music. In almost any music the dynamic range is so large that a signal may occasionally get clipped in an amplifier, but in a properly designed amplifier, transistor or tube, the signal gets into and out of clipping practically inaudibly. If the sound is terrible, it is the fault of the user. Get a larger amplifier or turr down the sound.

I get particularly annoyed when people begin to romanticize about the glow, warmth, ether, magic, and sc on of the vacuum tube. Thai is absolute hogwash. There is no scientific basis for the belief that one is inherently better than the other.

The trouble is that manufacturers test for the simple stuff—distortion, power, and frequency response—and certain manufacturers’ consortium guidelines tend to give everyone high marks. There’s a lot more going on. For one thing, a tube is a high-impedance device, and a transistor is a low-impedance device. When tubes are used, a transformer is usually needed to match them to the load. That’s because when the voltage to a loudspeaker stops, the loudspeaker should stop, but it doesn’t, because the speaker has mass, and so a voltage is generated back on the speaker wires, which is, in effect, amplitude distortion. Low output impedance (also known as high damping factor) causes the speaker to react to the amplified signal and not to its own inertia. Therefore, solid-state amplifiers tend to sound tighter, particularly in the bass region, where the speaker is more resonant and harder to control. This is also why “monster” cables help, because they continue the low impedance from the amplifier to the speaker.

If you want a tube-type sound, you can easily emulate it by hooking up thin wire between your transistoi amplifier and your speaker, thereby reducing the damping factor. If you like a boom-box, muddy jukebox sound, go for it. You’ll save a lot of time and money try- ing to locate a working vintage tube amplifier.

Wayne E. Chou
FOUNDER AND FORMER CEO
C/M LABORATORIES
RIDGEFIELD, CONN.

The Great Tube Debate

AS AN ELECTRIC GUITARIST I have an unabashed preference for tube amplifiers, though the solid-state ones have improved a lot over the past decade. The solidstates that sound best are the ones that emulate a particular tube amp, and no one makes a tube amp that attempts to emulate the sound of solid state. As good as modern solid-state amps are, I’ve yet to play through one that whispers or growls depending on whether I’m caressing or attacking the strings of my guitar. Only tubes can do that.

Nick Hanna
PORTLAND, ME.

The Great Tube Debate

IN THE FIFTIES, WHEN TUBES reigned, we used to say that a good amp clipped gracefully, no burps or hiccups, just an increasing fuzz and mushiness in the speakers. It’s my understanding that the tube amps used by rock guitarists are operated at or beyond clipping much of the time, precisely to obtain this desired fuzz, whereas the audiophile never clips his amp if he can help it, be it tube or amplifier. I suspect that if rock guitarists never drove their amps into clipping, they’d never notice the subtle differences between tube sound and transistor sound.

John Lowry
TERRE HAUTE, IND.

The Great Tube Debate

I’M HERE TO TELL YOU that the electron tube is alive and well. I have been employed for the last 12 years at Richardson Electronics, an electronics distribution company whose business was built on the electron tube. Mr. Richardson had the foresight to acquire several vacuumtube companies in the 1980s, and to this day the tube remains a vital part of the business here. We have truly carved a niche and stubbornly hold on to it.

Christopher Kane
RICHARDSON ELECTRONICS
LAFOX, ILL.

The Great Tube Debate

THERE IS ONE GROUP THAT Mr. Wolverton didn’t mention: all the old-radio nuts throughout the United States and elsewhere. We love old radios, from the 1920s and earlier up to those at the end of the tube era. There’s an active Internet presence on the subject, and there are companies that supply tubes and other parts. The Antique Wireless Association ( www.antiquewireless.org ) is the major organization supporting us all, and eBay has a very active segment devoted to tubes and old radios and other tube-powered devices. It’s a fascinating and enjoyable hobby.

Richard F. Bidwell
VIA E-MAIL

The Great Tube Debate

AS A FORMER TUBE ENGI neer I greatly enjoyed your article. But who picked the “vacuum” tube for your cover illustration? Some solid-state aficionado, no doubt. As nearly as I can tell, the device is a xenonfilled flash tube, only remotely related to the vacuum-tube types that were the focus of your otherwise excellent article.

THE EDITORS REPLY: MR. Newman is correct. The tube on the cover is a xenon strobe tube, not a vacuum tube.

John W. Newman
HOLLAND, KY.

Measuring Up

TOWARD THE END OF “The Mis-Measure of All Things” (Fall 2002), Ken Alder states that “compared with most nations, the United States has always had relatively consistent measures.” Of course, relatively is a relative term. In March 1798 in western New York, Joseph Ellicott marched off to mark the Holland Land Company’s territory. There was no national standard for a foot yet, so Ellicott collected a number of different rulers, took their average length, and made up a new standardized ruler, which he attached to the cover of each of the survey’s field books. As good a workaround as any, for the time and place.

David Minor
PITTSFORD, N.Y.

How Woz Invents

I ENJOYED THE INTERVIEW with Steve Wozniak (“Hall of Fame Interview,” by Jim Quinn, Fall 2002) and applaud his induction into the National Inventors Hall of Fame, but as a design engineer I was offended by his statement that “I was shocked when I encountered people in engineering who’d copy stuff. That’s not invention.” The industrial facts of life are that very few of us have the opportunity to be in the right place at the right time with the right idea and start an entire industry, as Wozniak did. Most of us work for companies with wellestablished product lines, and like it or not, the vast bulk of industrial design work is updating and improving existing products. Even new products are often designed taking advantage of the billions of engineering man-hours invested in making standard components. And Woz himself didn’t invent the television that he “snaked wires into” to use as a monitor, or the keyboard he used as an input device, or the chips he stuffed the circuit board with.

Jack Hagerty
LIVERMORE, CALIF.