Articles, Quotes & Information

• Tubes vs Transistors - Is There An Audible Difference? ( PDF ) by Russell O. Hamm, Journal of the Audio Engineering Society, Sep. 1972
• Tubes vs Transistors In Electric Guitar Amps ( PDF ) by W. Stephen Bussey, Robert M. Haigler, Proceedings of the IEEE, Ch. 1610, May, 1981
• The Cool Sound of Tubes by Eric Barbour & IEEE
• Transistors vs Tubes - Feature Comparison adapted from IEEE & Eric Barbour

• Tubes overload and compress comparatively gently, while transistors tend to abruptly clip as they "crash hard into the rails." A guitarist might explain: "At overload, tubes squish and transistors crunch." With several parallels, tubes can be thought of in terms of warm, incandescent light versus transistors as harsh fluorescent light. Not as a rule but generally, transistors make great "digital" switches with hard electrical edges, while tubes are inherently more "analog" and smooth. While some people insist that physical differences are not audible, internally, tubes are mostly vacuum, with a "space charge" or electron cloud that is electrostatically controlled by a varying voltage on a metal grid. Transistors are mostly resistive silicon, purposefully contaminated with impurities to enable conductivity in their crystalline lattice that otherwise insulates.
• Tubes use a charged electron plasma cloud in vacuum, while transistors force audio signal current through something not unlike dirty sand --possibly why 'brittle, hard, sharp, gritty and scratchy' often describe "transistor sound". Whereas rather linear tube circuits are usually simple, most transistor circuits require high negative feedback and more complexity. The All American Five was for decades a popular and common radio, requiring only five tubes. "Transistorization" happened for economy, not better sound --in this case, cheaper was just cheaper. In terms of gracefulness, straightforward simplicity and perhaps ultimately sound quality, transistors fall short.
• "We have called it the Transistor, T-R-A-N-S-I-S-T-O-R, because it is a resistor or semiconductor device which can amplify electrical signals as they are transferred through it from input to output terminals. It is, if you will, the electrical equivalent of a vacuum tube amplifier. But there the similarity ceases. It has no vacuum, no filament, no glass tube. It is composed entirely of cold, solid substances. This cylindrical object which I am holding up is a Transistor. Although it is a little bitty thing, it can... do just about everything a vacuum tube can do, and some unique things which a vacuum tube cannot do." - Ralph Bown, Bell Laboratories, upon publicly introducing the invention of the transistor in 1947.



Tubes Vs. Transistors, from newsletter #47 of The Absolute Sound magazine:

"... if you want to try to break across the border into something approaching realism, I still think you have to use tubes." --Harry Pearson, editor

"...tubes are more realistic. They have more bloom; they have more light; they have more body. They do that thing I call 'action,' which solid-state doesn't... tubes just eat solid-state alive." --Jonathan Valin

"... what you almost never get out of a solid-state piece of equipment is a sense of continuousness..." --Harry Pearson

"... there is a subtle but unmistakable sense of roundedness and solidity that tubes have..." --Paul Seydor

"... [tubes] give you the sense of having much more power. A 60-watt solid-state and a 60-watt tube amp never sound equivalent in terms of power." --Harry Pearson

"... I hear more stuff with tubes..." --Jonathan Valin

"You can tell some things from measurements ... but that tells you nothing about how the amplifier communicates the music. You get that from listening." --Robert Harley

• "Without a doubt, digital was the worst-sounding technical 'advance' of all time; for most of us, it was the first time a technical leap actually sounded worse than what it replaced, if you forget tubes to transistors..." --Stephen St. Croix, Mix magazine, Nov 2005, p.24 MIX Magazine Online
• "There is a clear and distinct difference, and in [30] years of testing equipment, I can't recall any situation where vacuum tubes didn't sound superior to transistors. ... I have always felt the deficiency of the sound of transistor equipment. Knowing this, I have always run a studio full of tube gear. Because of my 30 years' prejudice, I go to great lengths to be sure that this does not bleed over into the listening tests that we do." --Walter Sear, Sear Sound Studios, NY searsound.com
• The Vacuum Tube Rides Again
• Care & Feeding of Vacuum Tubes
• Tube Is Master
• High Tech Low Quality
• Recorded Sound Sucks
• EE's At Fender Put Guitar Amps To Work EE Times magazine, 13Mar2000
• 'Most people can sense and appreciate the subtle differences between a good meal and a great one, while others will deny there are any differences at all without ever tasting the food.' --adapted from George Short, North Creek Music northcreekmusic.com
• "The subjective correlation between Total Harmonic Distortion (THD) and what you actually hear is close to zero. After all, a low-fi rack-stereo receiver has far lower THD than the best-regarded triode amplifier. Does that mean that "all amplifiers sound the same?" No, certainly not ... Is the converse true — that measurements are meaningless? No, that's not true either; there are plenty of amplifiers with terrible measurements that do indeed sound terrible. . The fault is not with the subjective perception of the listener, but rather in the measurement itself...you can measure all you want, but a mass spectrometer isn't going to find a lot of difference between lunch at a high school cafeteria and the best dinner at a four-star restaurant. To foolishly assert that the mass-spectrometer is right and the restaurant customers are all deluding themselves is an example of simple ignorance trying to cover its nakedness with the fig-leaf of Science. ... All we can say for certain right now is that simple THD figures are not the right measurement for electronics!" --Lynn Olson, The Sound of The Machine, 1997-2003 ( source )



• I also love to cook and find considerable parallels between cooking and loudspeaker design. Specifically, 1) a simple recipe with the best ingredients is generally better than a complicated recipe with the best ingredients; 2) using the same recipe, the better the ingredients, the better the dish; 3) there are significant differences between the flavor of "identical" ingredients, just like there are significant differences in the sound of "identical" coils, capacitors, and resistors that come from different manufacturers. Also like crossover parts, I have learned that most people can sense and appreciate the subtle differences between a good meal and a great one, while others will deny there are any differences at all without ever tasting the food.' --adapted from George Short, North Creek Music northcreekmusic.com
• "I proposed it would be really cool if we could combine the warmth and depth - tonal realism, if you will - of the sound produced by an audio tube, with one of our state-of the-art motherboards ... Laughter turned into raves a few months later when we did our first lab demo ... The reproduced sound was absolutely amazing. It left everyone stunned." --Al Peng at AOpen America, about the AX4B-533Tube PC motherboard.
• "... then SPL [boom events] took the limelight ... SPL competitions have put us at a bit of a disadvantage ... it became a science: we've taken the entertainment out of it ... spectators are listening to a couple of short spurt burp tones ... nothing more than a few metallic rattles ..." --Paul Papadeas, AutoMedia magazine, May, 2004, pp. 38+, writing on what's wrong with car audio at large.
• "I've been selling home stereo equipment for over 15 years and I've found that when customers listen to a system in the store, 50% of them will prefer the sound of vacuum tubes and 50% will prefer the sound of transistors. But when you let the customer take the equipment home for a trial and play it on their own speakers in a system they are familiar with, just about all of them prefer the vacuum tube sound. It's the transistor equipment that they return. I think it is just because the vacuum tube sound is more pleasant to listen to. It doesn't get on your nerves after a while the way a transistor amp does. The few who prefer transistor sound may not be quite as familiar with the way real musical instruments sound." --stereosalesman, comment posted on digg.com, 10Aug2005.



• "As with everything in technology, once the new technology comes in, then people abuse it because they can do things they could never do before. I think we're getting to a point now where we realize that loud is not better. Everything used to be squeezed into this very narrow bandwidth, which meant the quietest and the loudest sounds were not very far apart...When everything is loud...your ears get tired and it creates a kind of energy that maybe you don't want...You don't realize that when you turn it off, there's a relief, because you're agitated emotionally just because it's such a loud sound, like being in a steel factory or something." --George Lucas, Mix magazine, Nov. 2004
• "I think people will always respond to emotion and to great songs sung well, and I think the vocalists in particular will always be in demand. There's nothing that approximates the human voice. In the end, when you come down to it, people want to feel something." --Janis Siegel, The Manhattan Transfer
• "I remember being with Stevie Wonder when he got his first Sony 2-track PCM recorder. Man, this thing sounded terrible! Anything it recorded took on a special broken-glass-sliding-on-sheets-of-stainless-steel character. But...it was noiseless and had startlingly low distortion. It was a new and novel sound, to say the least, and Stevie, as a technical pioneer, was committed to using it. Without a doubt, digital was the worst-sounding technical 'advance' of all time; for most of us, it was the first time a technical leap actually sounded worse than what it replaced, if you forget tubes to transistors and transistors to integrated circuits." --Stephen St. Croix, Mix magazine, Nov 2005, p.24
• CD vs. LP :: "This finding supports my own subjective impressions comparing the CD against the LP. I much prefer listening to the LP over the CD on my system. The CD sounds dull, congested, muddy, and lacking in dynamics. If I push up the volume, the sound becomes noticeably harsh and artificial. The LP on the other hand sounds more 'dynamic' and 'exciting.'" --Christie Tham, Comparison of CD, DVD, SACD article: part 1 • part 2 • part 3 • part 4
• "Panasonic B-flat Tube CQ-TX5500D is the world's best car receiver with a built-in vacuum tube. Another break-through by Panasonic in 2003 in search of excellence in sound. Ultra high quality amp section with separation in both signal and power for pure sound quality enhancement." --Panasonic advertisement, 2004 [They finally realized what so many have known for so long!]
• "In January 2005 London Underground announced that it would play classical music at stations prone to loitering by youths. A trial had shown a 33% drop in abuse against staff." Apparently, it matters what you hear, and, it probably matters how you hear it. --wikipedia: London Underground
• "We all know that vacuum tubes are the heart and soul of all legendary amps and are paramounts to their warm, rich tones. So we delved deep into the process of individually measuring every amp and painstakingly analyzing its dynamic properties in every detail. We spent a fortune building up a comprehensive collection of the most popular amplifiers, cabinets and effects in order to thoroughly analyze their tonal aspects, trying to reveal their sonic signatures. Our engineers have spent years getting to understand all there is to know about tube-powered amps, including how different tube types respond under various conditions. They've studied how a tube processes an input signal, how the signal affects other parts of the system, and then modeled them virtually. In vain. ... We started realizing what "tone" means, learning that a guitar amp actually "breathes" and that analyzing frequency diagrams doesn't get you anywhere. Transistors simply couldn't reproduce tube warmth and performance." --marketing blurb from Behringer on its V-Amp Modeler, 2007 (found at http://www.kinovox.dk/docs/Modeling.pdf)

• The Components of Sound A summary of factors affecting sound quality.
• 'Amp Defects Not Covered by Specs' by Norman Crowhurst
• The Perception of Pitch PDF, Frederic L. Wightman, David M. Green, American Scientist vol. 62, Mar. - Apr. 1974, pp. 208-215
• Essential Differences Between Good & Bad Guitar Sound by Dr. Samo Sali, Jul. 2004 salilab.org
• A New Methodology for Audio Frequency Power Amplifier Testing Based on Psychoacoustic Data that Better Correlates with Sound Quality, 2001 Masters Thesis by Daniel H. Cheever PDF An investigation of the hypothesis that accepted measurements of quantifying amplifier fidelity fail to correlate well with subjective sound quality. ... Specmanship rears its ugly head throughout the history of audio. As higher power density output devices (lower cost per watt) became available they were always less linear and so more required more negative feedback to correct. The more feedback, the sharper the onset of clipping, and the more abruptly higher-order audible distortions are introduced.
• The Look of Distortion adapted from Steve Bench
• Sound of Distortion by Jean Hiraga, Glass Audio magazine, May, 2005
• Waveforms, seen and heard in Reason adapted from psylux.com
• Science and Music by Sir James Jeans, Cambridge University Press, 1937: The timbre depends only on the relative energies of the various harmonics and not on their phase-differences. Differences of phase produce no effect on the ear.
• A Future without Feedback Stereophile magazine, January, 1998
• Scientists vs Audiophiles, Stereophile magazine, March, 1999, condensed:

  I'm not claiming that spooky or mystical events occur when you listen to your system. ... Every link in the chain, from the vibration of your stylus to the goose bumps on your arms, is grounded in physical processes. ... But that doesn't mean that we understand exactly what those processes are—especially the ones inside the brain. ...

  You can stand behind complicated truths or you can cling to simple mistakes. Those who feverishly insist that science tells us everything about audio treat science as an exact, finished product. But, any good scientist will tell you that there's much more in the world that we do not understand. Close examination almost always reveals increasing complexity. ...

  Some dissenting scientists and engineers may not immediately appreciate good audio, much as people who go to museums but have no idea why Picasso, Pollock, or Rothko are good painters. They're seeing exactly what everyone sees, but they're seeing it quite differently. ... Some may never be able to see why Picasso is a great painter or appreciate high-end audio; they remain rigid, unconvinced and unconvincible.

• 'Substance is something I never appreciated until I had decades of experience under my belt. A discount lens usually offers more features like faster speed or wider zoom range for less money. Likewise, cheaper cars usually offer better specifications, like fuel economy, horsepower or number of radio presets, for a lower price than, say, a Mercedes. You may realize that the Mercedes has a lot more substance and fundamental quality for which there is no numeric specification, and so you probably understand why a Mercedes costs more and delivers in ways not typically measured.' -- adapted from Ken Rockwell on photographic lenses, specifications and quality





• AutoStylin magazine Tech-Corner article ( PDF )
• Think of it as a Sparkplug for your Car Audio System
• Why Tubes?

• Speaker Wattage vs. Efficiency vs. Sound Pressure Level
• Introduction to Sound Recording, Geoff Martin's excellent book online
• Motorola, Lear Jets, 8 Tracks, and Early Car Audio recording-history.org

• Damping Factor by George Augsperger, JBL, Electronics World, Jan. 1967
• Cathode Phase Inversion (PDF ), Otto H. Smith, 1941
• The Fleming Valve
• Amplifier Fundamentals PDF, AGO 4239A
• An Ultra-Linear Amplifier PDF, David Hafler, Herbert I. Keroes, Audio Engineering, 1951
• Harmonic and Intermodulation Distortion PDF, J. N. A. Hawkings, 1988