Do Tube Amplifiers sound superior to solid state? I’ve heard they don’t ‘clip’ at high output levels like solid state amps, and provide high current output into difficult speaker loads better as well. Every guitarist I’ve known, pretty much, slathers over ancient Fender tube amps as well, primarily for their inherent distortion characteristics at high levels, which seems to be paradoxical to faithful music reproduction.
But why do “audiophiles” insist on tube gear, isn’t it possible to design a solid state device with the same frequency response as hollow state gear? I read about people who insist on listening to analog vinyl only, through minimalist pre-amplifiers sans tone controls and outrageously expensive interconnects to astoundingly expensive amplifiers and speakers. Solid state gear is much more reliable, for one thing, and cheaper. From a technical standpoint, there’s no comparison. SS gear is better.
What’s the straight dope on Tubes versus Solid State?
Audiophiles have been arguing about this for decades.
Personally, I do not believe it is possible to hear something that cannot be measured. It actually goes beyond that; we can measure things that are impossible to hear. Having said that, modern SS amplifiers have superior specs to their vacuum tube counterparts (harmonic distortion, TIM distortion/slew rate, noise, bandwidth, linearity, etc.), thus I believe SS is superior to vacuum tubes. (SS is also more practical; it is more reliable, less expensive, requires less space, and more efficient.)
This is not to say I don’t like vacuum tube amps. I had the chance to hear a pair of class A vacuum tube monoblocks a few years back, and they did sound very good. (Of course, they also looked good, which I believe is the primary reason people like them.)
The fundamental difference between semiconductor and valve amplifiers is in their ability to handle extreme electrical transients.
Semiconductors, despite their superior rise times and response characteristics, nonetheless exhibit a distinct lack of grace when they are pushed to their upward limits of gain. A phenomonon known as roll-off, whereby a signal approaching its theoretical maximum gradually begins to become delimited, is entirely absent in solid state circuitry.
This is where tubes are superior. As the signal rises to its maximum amplitude, the output begins to gently roll off and flatten out. This is much more desireable in musical sound production. Transistor based amplifiers undergo what is known as “clipping”, whereby the top portions of the frequency’s waveform are literally truncated or clipped off. This results in a distinct loss of fidelity and introduction of square wave timbres into the once sinusoidal waveform.
An additional aspect is the harmonic overtones unique to each of these two different electronic components. Transistors tend to emphasize the odd order harmonics, namely; 1/3, 1/5, 1/7 of the base frequency and so on. If you are familiar with the strange timbral qualities of the clarinet you will quickly recognize the less common voice of that instrument’s envelope in a clipped signal’s tonal characteristics.
Tubes tend to reinforce the even order harmonics, namely; 1/2, 1/4, 1/6, 1/8 of the fundamental frequency and so on. This is a much more natural set of overtones found in nearly every acoustic instrument. It is one more reason that tube amplifiers have such a “warm” tonal quality to them.
Personally, I’ll take a tube amplifier for my electric guitar anyday. When driving positive feedback and other extreme transients, the gentle roll-off of a valve circuit is unbeatable for premium sound production. Much of this same argument also applies to sound reproduction as well.
Valves and tubes are much more resistant than solid state electronics to the electromagnetic pulse of a nuclear strike, so all you solid-state guys won’t be able to listen to music after the bomb drops, hehe, erm…
Isn’t it possible to construct solid state gear that conforms to the characteristics inherent to the “tube sound”? That’s what I don’t understand. Seems like it should be fairly easy to duplicate.
As a Stereophile subscriber for over ten years you would think that I could give some valuable insight into this subject. But I can’t. It’s a battle of the experts. Some prefer tubes, some prefer solid state. The only way you can decide is to hear for yourself. I heard an expensive tube amplifier (can’t remember the brand) driving some Green Mountain Audio speakers and the sound was terrific, but there was nothing that I could attribute to tubes as opposed to solid state. I have always had solid state pre/power amplification because of the convenience (as was stated above).
There are a few solid state companies that advertise a “tube” sound. Bob Carver in his Sunfire designs claims that the tube sound is a matter of the output impedance and his amplifiers have “Two output options: Current source for a warmer, more open tube sound and voltage source output for a faster, more dynamic solid state sound.” No one really seems to be copying this aspect of the design, however. I have read reviews of other solid state amps where the reviewer says it has a “tube-like” sound. I’m not sure what this means, as I don’t have extensive reviewing experience, but I gather “tube-like” is at least partly a result of the even-order harmonics as discussed above.
I have a Fender amp with a tube overdrive channel and a solid state clean channel. The difference in timbral quality between the two channels is quite noticeable, especially at higher volumes. I almost never use the clean channel, and just turn the gain down on the overdrive channel. My friend has an older Fender Jazzman tube amp and I swear it can make any guitar sound 5 times better.
Sounds to me like the old “digital recording vs analog recording” debate. Am I understanding that the tubes’ performance is truly only noticable at extremes? If so, why push your equipment so damn hard?
Some of the lore transmited above comes from David Tarnowsky, the founder of ADA amplifers.
His was the company first to manufactur an individually selectable dual source combination solid state and tube driven guitar amplification system. This gave you the fast attack response of the transistor balanced with the “warm” tonality of a tube amp.
Another method involves using a “contour” function. This is a complex three-or-more stage bandpass filter or equalizer that shapes the amplifier’s frequency spectrum. Any such method as this inherently depletes the overall signal’s RMS value and is therefore unacceptable.
Find which type of sound signature you like the most and run with it. I still have a lot of fun driving my self designed;
Bare-back-rock-maple-necked-full-gold-Schaller-triple-Seymour-Duncanized-Fender-Pseudocaster-with… a Floyd Rose
…through a vintage Gallien Kreuger VRG-200* solid state guitar amp through a GK 4x12 stereo cabinet.
Like one of the very first GK amps played by Carlos Santana at Woodstock.
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erislover, please note that I made the distinction between production amplification and reproduction sound reinforcement. There is a tremendous difference.
In sound production, circuit saturation is usually accompanied by full spectral response. Delimiting the intrinsic value of an amplifier’s output will typically result in a distinct and undesirable attenuation of the amp’s frequency response.
This is what is behind the Spinal Tap joke about, “Our’s go up to eleven…”.
The better you provide the fullest drive signal possible, the better the final waveform. Most people are uncomfortable with high volume sound generation, but it sure is fun.
If your amplifier is correctly biased and driven, it will be operating in its linear range, which means the difference in non-linear response between tubes and transistors is irrelevant.
Frankly, I think the big difference in audiophile amplifiers is that the tube amps have a lot more distortion (up to 10%, even for some very expensive amps), but tube amps exhibit that distortion by adding what we call ‘warmth’. In other words, you’re not hearing the true sound, but the sound distorted to sound ‘warmer’.
Speaking as a classical musician, tube electronics produce a sound that is much closer to what I hear live. Therefore I cannot accept the “euphonic distortion” concept- everything has distortion, of course, but how can the extra thd in a tube pre/or amp make it closer to the real thing?
There are several things that stand out for me-
one important thing is microdynamics- I can hear the small dynamic nuances in a performance much more clearly with tubes- I have never heard an SS system that was as revealing in that area as even an average tube system. Most SS systems sound to me like they have only two dynamics: soft or loud.
Another thing is noise- somehow an SS system involves the noise with the music- with tubes what noise there might be is separate from the music.
Now I don’t think that there is some “unmeasurable magic” in tubes, but I do think that the measurements in ads don’t have that much to do with how much of the music you can actually hear. JDM
With guitar amplifiers the amplifier is a part of the instrument, it adds to the sound. Guitar amplifiers are not intended to “faithfully reproduce” the sound of the unamplified guitar. They have responses which are a long way from being “flat”.
Listen to any guitarist and chances are that some kind of distortion or overdrive is an important part of their sound (not necessarily all the time). Tube guitar amps produce a very musical sound when overdriven. Because tube amps sound good when overdriven, they can generally be played a lot louder than a solid state amp for a given wattage rating. The solid state amp when pushed into natural clipping sounds harsh by comparison.
This isn’t to say that there haven’t been leaps forward in producing tubey sounds from solid state amps (generally by using digital modelling technology), but as yet solid state hasn’t quite got there.
This is all about musical production of course, as far as reproduction goes I think tubes are less important, but some people obviously prefer the sound.
At the end of the day, it depends on what sound best to your ears!!
Ah, a voice of reason in the pseudoscience world of high-end audio!
I totally agree with you, Sam.
Ideally, an amplifier should be 100% “transparent,” i.e. it should have no “sound” of its own. That’s why it amuses me when I hear people talk about the “warmth” of tube amplifiers. Don’t they know it’s “warm” because it is distorting the signal?
Let’s face it: if tube amps were so great, why wouldn’t electronics R&D labs all over the world use them? Why doesn’t the National Institute of Standards and Technology use them for their instrumentation needs? Why don’t engineering labs at universities use them? Why doesn’t NASA? How about the Air Force Research Lab? Do audiophiles know something these folks don’t know?
As an example, I operate a bunch of electrodynamic shakers where I work. These things are basically big speakers, and I wouldn’t think of using a tube amp to power one.
Now to really discuss this issue intelligently, we must define the specs of an ideal audio amplifier:
0% THD
1 Hz to 100 kHz, +/- 0 dB
perfect phase response
perfect linearity
sufficient dynamic range for desired listening level
no TIM distortion (i.e. infinite slew rate)
0 ohms output impedance (note: many argue otherwise)
This would be an “invisible” amplifier, and thus would not have any sound at all. And what technology comes closest to this ideal? Solid state electronics.
One more thing: my response applies to audio amplifiers intended for “faithful reproduction of pre-mixed & mastered music” (such as a power amp used in a home stereo system), not a guitar amp.
I don’t know much about the technical stuff here, but I have been playing in bands with the same guitarist for 6 years. When we first started together he was using an SS amp, and now he uses tube. The biggest difference I can hear is that the SS amp had no balls. It had no character. It was a very flat sound. The tube amp has some depth to it and a much fuller sound. I like it much better, especially for the blues.
I’m not well-read in this field at all, but I wonder if a little distortion – even in reproduction – might be a good thing. I’ve read that dithering (adding noise to a digital signal) actually helps the brain perceive extremely high or low sounds.
Still, even though I love my vintage HH Scott, I can’t help wondering if I’d really know the difference in a blind comparison with a solid state amp. And how much of the “warmth” is really a psychological reaction to those cool-looking, orange-glowing tubes.
For audio reference and day in/day out reliability you can’t beat solid state but for a lot of people there’s a difference between that and what’s pleasing to the ear.