Tubes vs Transistors: An Audible Difference? 686
cgenman writes "Are those vaccuum tubes worth the extra price? This paper, a transcript of a speech to the Audio Engineering Society of New York, indicates so, though the reason is surprising: Overloaded tubes behave better.
While the speech itself is from the early 70's, the paper takes on new importance with the recent trend in louder is better music."
Of course... (Score:3, Insightful)
If you like the distortion tube amps give (remember, you're not getting the audiophile shound, you're getting "nicely" distorted sound) I'm sure a DSP can do it for you. Even an EQ would probably help.
Re:Of course... (Score:3, Insightful)
Re:Of course... (Score:5, Insightful)
It also has little to do with dollar-for-dollar comparisons of circuit cost. If an amplifier makes noises that sound better to the listener, then they are a better solution the one which has a less good sound quality.
Unless you're talking about car audio. Then, apparently, 43,000-watt amplifiers are only $200 at the local Car Audio Mart, and the buyers care little about output quality.
Re:Of course... (Score:3, Interesting)
Re:Of course... (Score:5, Informative)
Carver created a solid state amp which pretty much mimicked a $10K tube amp and no one could tell the differencec in blind tests.
Re:Of course... (Score:3, Insightful)
Sure, transistor amps are more powerful dollar for dollar, but what does that dollar sound like? What application are you putting it towards? There are no clearly defi
Re:Of course... (Score:3, Insightful)
Re:Of course... (Score:3, Insightful)
You're kidding, right? Pro audio engineers can hear the difference between converters, and do every day. One quote from a message board:
"For those who want to verify double blind and statistically the difference between converters, this [PCABX] might be the ticket...I was able to pick out the Mytek 8-96 consistently over Protools 192 8/8 times."
Re:Of course... (Score:5, Insightful)
I base this opinion (yes, opinion) on: several years as a professional audio engineer; several years as a guitar amplifier repair technician; several years as a semi-professional guitarist; and two degrees (working on a third) in Electrical Engineering.
Sibling posters who believe that DSP can do anything are correct up to a point: DSP can achieve any given transfer function, up to a desired level of accuracy. You need more accuracy? Increase the bit depth and sample rate, tweak the processing. However, the bug stumbling block is this: you gotta know what transfer function you want to emulate first.
This is true to a point... (Score:3, Interesting)
Re:Of course... (Score:5, Funny)
Of course, DSPs can only apply mathematical transformations to the signal, whereas tubes impart magical qualities that defy quantitization, such as warmth, openness and bredth of sound stage.
They are called vacuum tubes, but they each actually contain individual fairies, all supplying your music with a limitless supply of fairy dust.
Not fairies, just hard-to-make sounds (Score:5, Interesting)
Of course not, but they do contain extremely-hard-to-model non-linear responses of a bewildering variety of kinds. If they didn't, then no one would pay $500+ for DSP emulators like Native Instruments' recently released Guitar Rig, and everyone would just code their own in csound or Max/MSP.
In other words, the software market shows that it takes quite a lot to mimic the sound of classic tube amps (and speaker cabinets, etc.). So, when someone (who actually uses these things on a daily basis, for example) says that tube amps can't be matched by software, they're not necessarily saying there are magical fairies in their tubes (though some meatheaded guitarists might say that), they could be reflecting a knowledgeable point of view on the reality of the current situation.
Personally, since I use these things a lot (I do a lot of home recording) and have seen how they've progressed, I have no doubt that software will eventually match classic tube amp sounds for guitar; it may not even be that far in the future. But it ain't here now.
Re:Not fairies, just hard-to-make sounds (Score:5, Informative)
Some people like the sound of the tube amp better, others don't see any significant difference, and there are those that don't like it at all. Put it like this: what is an amplifier supposed to do? Why, it is supposed to amplify, of course, and the more precisely, predictably and accurately it does that is a good measure of the quality of the amplifier. The closer you come to achieving a one-to-one correspondence between the input waveform and the signal presented to your speakers the better your amplifier. Conversely, an amplifier that modifies, distorts or otherwise results in significant variation between the input and output waveforms is a worst a lousy amplifier and at best functioning as a signal processor in its own right.
What it comes down to is that the extremely-hard-to-model non-linear responses of a bewildering variety of kinds that you describe indicate that the tube amplifier is not faithfully reproducing the original recording and is distorting it in complex and unpredictable ways. Yes, it may do so in a pleasing manner and one may very well prefer the modified sound, I have no problem accepting that. But that is not intrinsically different from saying that I like what my 20-band equalizer or my Alesis effects processor does to the sound. And given the decades-long controversy on the subject, the presumption by tube amp afficionados that their sound is inherently "superior" is a bit hard to swallow, particularly as we are talking about one of the most subjective experiences that human beings can share. Personally, I like the sound of some of the tube systems I've heard, but for my part I wouldn't say that they are, under all circumstances, simply "better."
Re:Not fairies, just hard-to-make sounds (Score:3)
Re:Not fairies, just hard-to-make sounds (Score:3, Interesting)
The reason why valve amps are still popular and DSP hasn't completely replaced them is because an overdriven valve amp colours EVERY aspect of the sound, from additional harmonic content through dynamic response to filtering. The transfer function is extremely complex. I believe that the modelling amps & preamps (like Line 6 POD-type devices) involve convolving the input wi
Re:Not fairies, just hard-to-make sounds (Score:3, Insightful)
Amps are two things, instrument or playback. (Score:3, Interesting)
That said, after that lovely guitar/tube amp sound is recorded somewhere, I'll be playing it back on a nice transistor rig at my house. B
Re:Of course... (Score:3, Insightful)
Re:Of course... (Score:2)
Re:Of course... (Score:5, Interesting)
The issue brought up in the article is no longer a concern. There are transistor amplifiers with soft clipping, and clipping shouldn't happen in normal situations anyway.
However, high-quality tube amplifiers have one characteristic that class B transistor amplifiers do not: zero negative feedback. Transistor amplifiers need large amounts of negative feedback to obtain low distortion. Tubes don't need it. That means you have virtually no high-order distortion harmonics in a tube amplifier, while transistor amplifier distortion is mostly high-order.
It has been shown that high-order harmonics sound very nasty, even in tiny amounts. It has also been shown that the human ear produces its own low-order distortion, so low-order harmonics do not sound objectionable to us. Now put two and two together. Tube amplifiers may not have very good distortion numbers, but the type of distortion they produce is not as objectionable to a human. It's not that 2nd harmonic distortion sounds good -- it doesn't. It just doesn't sound as bad.
Next on Slashdot: Core Memory vs. Transistors (Score:4, Insightful)
Tubes are LOWER distortion than solid-state. (Score:2, Informative)
Solid state competes only by having very high gain and using feedback. There is absolutely no way for solid state devices to compete with tubes in terms of distortion in the f
Re:Of course... (Score:3, Interesting)
You have a source for tubes than can handle (assuming we are hooking up some magically-able-to-handle-3kw-home-speaker) 20 amps of current? If so, show me the money. Otherwise, you know the old saying, shut up or put up.
I say this because I am certain I can find transistors that can do that.
Now, since I can't find ANYTHING in a tube amp that can handle 3kw (examples, please), I'll post this [vacuumtube.com] example, a 200 watt tube amp running at
Certainly! (Score:4, Interesting)
So yes, there are tubes which can handle extremely large (nigh-insane) loads. The tubes might be big, bulky, and made of ceramic, but they exist.
Re:Of course... (Score:3, Informative)
V = I * R
P = I * V
therefore, substituting I*R for V, we get
P = I^2 * R
If P = 3000 watts, and it's hooked up to a standard home speaker (8 ohms), rearranging, we get:
I^2 = P / R
I = (P/R)^1/2
I = (3000/8)^1/2
I = (375)^1/2
I = 19.364916731037084425896326998912 amps
If you managed to squeeze 500 volts into your standard speaker, you'd have:
P = V^2 / R
P = 500^2 / 8
P = 31,250 watts
At a current of:
I = V / R
I = 500 / 8
I = 62.5 Amps
(I'd suggest using 00 AWG cable for that
The recent trend in "louder is better" (Score:5, Insightful)
Re: (Score:2)
Re:The recent trend in "louder is better" (Score:2)
Re:The recent trend in "louder is better" (Score:2)
The promoter had actually only allowed him to set up half of his amplification, the concert hall was only about 30 yards
Re:The recent trend in "louder is better" (Score:2, Interesting)
Play This Loud (Score:2)
The answer: Louder is better until the sound is distorted or your ears hurt.
The above does not apply to people who configure sound in their car to play at 120 decibels using the pavement to help modulate the bass. Those folks are after an entirely different sensory experience.
Re:Play This Loud (Score:2)
The answer: Louder is better until the sound is distorted or your ears hurt.
That's the point: It's disorted before it's even had a chance to play, and it makes the discerning listener's ears hurt. Nothing the user can do can make that CD sound better. Joe Bonamassa's "So it's like that" CD is just as badly mastered; it's the worst one I have. It's so bad, I won't even listen to
Re:The recent trend in "louder is better" (Score:5, Insightful)
When I was younger is used to love to "KRANK IT UP!!".
I got my hearing checked recently by a new doctor and afterwards she asked me if I had ever been in the military. I said no, and she looked at me sadly and asked if I like to listen to loud music. To this I said yes. She shook her head and told me that my high frequency hearing was gone, and that I'd start to notice difficulty hearing low volume sounds and general difficulty hearing by the time I'm 40 or 45 if I keep it up.
I asked her why she asked me the question about the military, and she said 2 words. Grenades and explosions.
Sadly, even though I stopped the high volume listening years ago (7 years before this exam) I guess that it took it's toll as I do have trouble hearing normal conversation...especially where there's background noise. We have a new truck, and I can't even hear the blinker noise over the sound of the road. My wife has to contantly tell me to turn it off.
Dumbest f*n thing I ever did to myself.
wbs.
Re:The recent trend in "louder is better" (Score:4, Insightful)
I'm surprised (and a bit sad about) the number of students who can't hear the 16khz tone. Most of them are also the ones who had their CD players/walkmans cranked up all the time.
Just remember, if your ears are ringing, it means they're close to, or actively being damaged by the sound.
N.
Re:The recent trend in "louder is better" (Score:3, Insightful)
Is that why mp3 is so popular? Because even though it doesn't keep frequencies > 16khz, people don't miss them anyway?
Re:The recent trend in "louder is better" (Score:3, Informative)
The explanation for this is quite messy, but google the terms "Nyquist limit", "Shannons Sampling Theorem" and "Aliaising Noise" if you want to know more.
Try generating a slow sweep from 10k to 22.1k and you'll probably hear a multitiude
Re:The recent trend in "louder is better" (Score:3, Interesting)
Never trust your speakers. Get a sound pressure meter. Take it's output and check the THD. You may find the sound at 45 DB sounds quiter than the one at 67 DB. Many home stereo speakers have more than 15 DB changes when swept from 200 HZ to 5 KHZ. Only the very best speakers hold the level within 10 DB from 100 HZ - 20 KHZ. Most home stereo speakers won't give the response curves in their technical data.
They're talking about compression (Score:3, Informative)
Re:The recent trend in "louder is better" (Score:2)
Re:The recent trend in "louder is better" (Score:5, Informative)
Recording too loud is bad, but labels feel it gives them a comparitive advantage because it's the only way they can effect the final listening volume, and subjectively louder music sounds better.
Explanation with *Pictures* (Score:5, Informative)
The problem with this is you end up with horrible range [mindspring.com] that you can't do much with. Loud sounds end up clipped so that the softer sounds can sound 'louder'. Here's why it sucks: You lose a lot of the music's quality. When I turn up this song [mindspring.com], my stereo dac becomes the limiting factor. When you turn up crap like this, [mindspring.com] the sound waves are already clipped. The jokes on them.
People like tube amps because they add a little bit of harmonics that sounds nicer to our ears. Tubes sound 'warm' and they fail gracefully when overdriven. It's an old battle that no one will win, but most muscians go with tube amps so they can't all be wrong
Re:The recent trend in "louder is better" (Score:5, Insightful)
I use to record from vinyl (and CD) to high quality casette decks (way back before there were CD burners). The first step to make a good tape is to listen to the whole song, and watch the db level meteres, and adjust them so that the LOUDEST sound in the song is less than zero db (or whatever level your tape deck uses). This way when you play the music back it sounds correct. Soft parts are soft, loud parts are loud, and all those transients come across loud and clear.
What they are complaining about is that about is that newer CD's are recorded so even the softest sound is LOUD which means the loud parts of the song CAN'T get louder which makes the whole thing sound terrible. They just 'clip' the loud parts reducing their volume. Apparently this is done because 'loud sound better' and big music compaies think if their CD is 'louder' on the radio it will sound better. Of course, most music played on radio stations is not played directly off CD's! It gets recorded, 'normalized' and played from big digital jukeboxes.
What these audiophiles want (and most classical music CD's are still fine) is for the producers to let the large dynamic range that CD's support actually be USED to make good sounding music. If the CD is well recorded you can turn up your amp to "11" and still have great sounding music (as long as your amp has the head room to punch up those loud bits).
Re:The recent trend in "louder is better" (Score:5, Informative)
A compressor is a device that says when the music reaches a certain decibel level, reduce the volume by X (X=compression ratio). So with a compressor you can take a song and crank it up super loud, without fear of ever actually clipping the signal or the system (it hovers right below 0db).
The result of this is that if you looked at a compressed waveform, they are no dynamics in it at all. The peaks and values of the entire wav are all maxed out. While this is louder, you have almost no dynamic range. Compression comes at a cost - most engineers these days don't seen to realize this.
CDs aren't actually recorded like this. The recordings are fine - it's when they go in to get the whole song (and CD) mastered that this happens. Audio Engineers are under increasing pressure to make the CD "sound louder" by the PHBs.
Re:The recent trend in "louder is better" (Score:4, Informative)
One reason for this, IMO, is that people are listening to more and more music in cars. Cars suck for listening to music in: they're loud. Even a quite car has got a fairly high level of background noise. This means that you've only got a limited amount of range left to present the music in, which means that listening to high-dynamic-range music just doesn't work.
(Ever tried to listen to classical music in the car? Ever found yourself adjusting the volume to make the quiet bits louder and the loud bits quieter? You've just run out of range. Modern music is easier but it tends to have a much smaller range anyway, even without compression.)
Compressing the range makes the music much more accessible in cars (and other high-noise environments). Of course, this makes it suck when you're listening to it on real audio equipment. But since radio is a major market, and most radios these days are in cars, there's a major push towards compression.
(Incidentally, as anyone who actually knows anything about audio equipment will tell you --- unless you're in the habit of listening to music in your car with the engine off, spending serious money on a car audio system is just not worth it. That background noise will ruin everything, every time. Spend the money on a digital jukebox instead and leave the high-quality audio at home, where you can listen to it in the environment it deserves.)
Re:The recent trend in "louder is better" (Score:3, Informative)
That's not the way the poster meant it. You should read the first article he links to. It's about how recently CD's are made to sound louder and how this causes the music to sound bad. There are some examples or rock CD's from not many years ago that did not exhibit this awful practice.
Tubes also degrade over time (Score:5, Interesting)
Regardless of which one you feel is more accurate in its source reproduction, solid state devices have the advantage in that they pretty much (not 100%) maintain whatever sound characteristic they start with.
Re:Tubes also degrade over time (Score:3, Informative)
Re:Tubes also degrade over time (Score:2)
I have to question this.... (Score:5, Insightful)
Digging up an ancient speech which probably SPARKED the religious war in the first place is idiotic, in my opinion.
What's next? Will we dig up some argument from the 1880s about the superiority of DC-delivered electricity?
Re:I have to question this.... (Score:2)
Yes I'm being an idiot.
Re:I have to question this.... (Score:2)
Re:I have to question this.... (Score:2, Funny)
Re:I have to question this.... (Score:2)
Don't tell anybody, but that was going to be next week's /. article.
Re:I have to question this.... (Score:2)
so.. if you use transistor amps wrongly you're going to get a clipped output.. or something.
like you wouldn't be able to abuse a tube amp.. tube amps are 'cool' though, cool in the watercooling sense of cool. fun, but not so useful like most of the hobbyists would like to believe.
Re:I have to question this.... (Score:5, Informative)
Maybe its a war for audiophiles, but for musicians, there is no dispute. The vast majority of professional musicians use tubes for the reasons stated in the article and others. Transisitors are used for different things, such as when size and heat are a consideration, like in a practice amp.
I never understood why there was a debate anyway. Tubes sound better, transistors are much easier to work with. They each have their place. You can make each sound good or bad by design, but when all is equal, tubes sound more pleasant to the ear, while transisitors look better on paper. I tend to believe my ear rather than a piece of paper. My home stereo is transistor, my guitar amps are tube. This is because I want good sound at moderate levels and excellent reliability from my home stereo. For my guitar amp, I am willing to put up with lower reliability and higher maintenance to get the dynamic range, uncolored sound, natural compression and punch that only tubes can bring.
The flame wars are pretty silly, its like arguing "horse vs. car". Obviously the car is better in most cirumstances but the horse is handier if you are where there are no roads.
Oh, the relevence today is that the quality of transistors today are not as good as they were years ago in some respects (as you state, they have changed) yet my guitar amps still use the same tubes other amps used 50 years ago: 6V6, 6L6, 5880, EL34, EL84, 12AX7, etc.
It seems like.. (Score:3, Interesting)
Yeah, so? and? what? who cares? (Score:5, Insightful)
Also how relevant is this? 30 years ago, we've got all kinds of DSP going on now and very efficient transistor amps putting out a boatload of power before they become strained.
The problem with the louder-is-better issue is the albums themselves. They're mixed horribly. You can play them on a cheap boombox or a system costing thousands of dollars. You'll just hear the garbled shit more clearly on the multi-thousand dollar system.
Re:Yeah, so? and? what? who cares? (Score:2)
www.superaudio-cd.com [superaudio-cd.com]
Overloaded = shouldn't happen (Score:5, Insightful)
The only real place where this has any impact is in recording and performance; amps are frequently overdriven to provide a "fuzzy" effect - guitarists will know exactly what I'm talking about here. There, tubes and transistors sound quite different, and tubes do sound quite a bit nicer.
I'm sick of all the "audiophiles" who claim that a non-overdriven tube amp provides a better reproduction of any given sound than a similar, transistor-based amp. The fact of the matter is, transistors provide a better sound reproduction, as there's less interference from things like the tube's heater or outside magnetic fields. Whether it sounds better or not is up to you, but don't try to tell me that it's a better reproduction.
Re:Overloaded = shouldn't happen (Score:3, Insightful)
Distortion can take two forms:
1) Distortion that makes the sound you listen to sound less like the live event
2) Distortion that makes the sound you listen to sound more like the live event
Given that transistor based amplification is essentially perfect by any reasonable measuring system, and it's distortion is minimal, it may very well be accurately reproducing a h
Re:Overloaded = shouldn't happen (Score:2)
The recording of the live event removes some elements of the signal.
If the playback of the recording adds some stuff which is not in the recording, but sounds more or less like the stuff that got removed in the recording process, then your playback now sounds more like the actual event.
(I don't know if I believe this, but that's the argument he's making)
Re:Overloaded = shouldn't happen (Score:5, Insightful)
If this makes me sound like a Tube-a-phile, let me mention I'm an analog circuit designer and my profession and personal opinion that >90% of most tube-a-philes are ignorant fools. There are a handful of exceptions. Norman Koren [normankoren.com], though he is out of the audio hobby, knows what he's talking about. His writings should be required reading and required baseline knowledge for anyone who wants to mindlessly spout off about tubes being better over transistors. He's pro-Tube, BTW. His analysis is some of the only cogent and technically correct writing I've seen on the subject. AFAIHS, most pro-Tube audiophile magazine articles are written by people without actually knowledge of or experience in analog circuit design (building one or two tube amplifiers in your garage doesn't count) so I'm always dubious but I'm open to qualified and valid arguments, either way. This question of Tube-vs.-Transistor is usually irrelevent with bad circuit design: transistor amplifiers can be as good as the best tube amplifiers and tube amplifiers can be as bad as the worst transistor amplifiers. Device technology is not some magic bullet and claiming such only demonstrates one's stupidity and ignorance.
That said, one need only look at the rise of MP3 to see that most of the population can't hear the difference if there ever was one. This is something that the RIAA complete missed. It's also something that SuperCD and AudioDVD format promoters seem to have fatally overlooked (from an MBA sense, the market cap for such formats are far smaller than they claim or seem to believe). Most environments in which we listen to music are noisy (car, office and even home), and further most of us can't hear well enough or have the ear training to discern bad from good even with moderate quality equipment. The available "channel capacity" between our audio sources and our ears is generally far less than the 16-bits dynamic range/44.1 KHz data rate due to this ambient noise floor. Add to that the channel capacity limits between our ears and brain: I had my hearing checked when I was 19 and even then I had no significant perception over 16 KHz (which is statistically "normal" for 19 yo males). I'm in my 40s now and I've noticed my hearing getting worse since that! My iPod and its MP3 are certainly lower quality than the ideal but I get to take my entire audio collection with me anywhere in the world - nothing like sitting on the beach in Nusa Dua, Bali and feeling a particularly obscure recording from your collection would be appropriate for the moment and just playing it! That and hearing fidelity limitations tends to trump the quality argument in most cases.
Golden Ear performance is a requirement for only a tiny and limited market of audiophiles and historical archival use. The claim that overload handling differences is real and potentially relevant. Mr. Koren's analysis shows (from the pro-Tube camp) distortion is often an artifact of bad circuit design rather than necessarily a device technology issue (esp read his article on negative feedback) - bad design pervades both the Tube and Transistor sides of the audio industry. Most people won't be able to tell the difference anyway, which, from an economic-forces-driving-technology-options-and-dev elopment point of view, that's all the matters in the long run. Hence most audio is IC transistor-based, and increasingly, computer/synthesizer-based anyway.
JG
I remember this argument (Score:3, Interesting)
That being said, the obvious answer is not to overload the amplifier inputs. But if you really, really like the effect of an overloaded tube amplifer it is easy enough to simulate with a little filtering. (Analog or digital)
If you really want that old "vaccum tube" feel to the sound, try injecting just a touch of 60 or 120 Hz hum into the output.
Maybe it's obvious and noone has to say it... (Score:3, Insightful)
The CD has outlived its usefulness to the labels. They want to move people onto a copy-protected medium so that the MP3 problem is squashed. And think how much better the properly leveled SACD will sound next to the clipped CD.
Professional user's perspective (Score:2)
This assumes that you do not clip the amp.
Most audible differences between amps are due to overload recovery artifacts.
Class A tube amps overload better than class A/B solid state amps.
Tube systems are popular because they are somewhat easier to design and can be sold for more profit to fashionable audiophiles.
One good solution to overload is to buy a bigger solid state amp.
Professional audio systems require a 24dB ov
Valves (Tubes) In Ham Radio (Score:4, Informative)
The front ends of receivers ALWAYS behave better when a tube is used because of the gradual distortion that has already been mentioned. On some of the bands that hams use receivers overload easily and the tube characteristics coupled with a high voltage power supply (80 volts or so compared with 12 volts for a transistor rig) can save the day.
Power amps for transmitters are always best when a valve or two is used. There are amps out there that use FETS and exotic technology but if you want to shove 2Kw up an antenna the only way to do it is with some heavy duty tubes.
Ed Almos
Budapest, Hungary
Re:Valves (Tubes) In Ham Radio (Score:4, Informative)
I would not call solid state RF amps "exotic technology." The technology has been well understood for atleast three decades now. However, building a high power solid state amp may be beyond the average hobbiest. At least, building a similar vacuum tube amp may be much easier. I haven't tried building either. For an idea of the state of the art in solid state amplifiers have a look at the Nautel products [nautel.com]. The image of the 2.5kW transmitter [nautel.com] is telling. It is not a small little transmitter.
While technically it might be true... (Score:2, Insightful)
I think when loudness becomes music's most important quality, the word "music" should be placed in quotes.
Really, why care about perfect reproduction when your ears are bleeding?
AOpen Tube Sound Motherboard (Score:3, Insightful)
Odd harmonics vs EVEN Harmonics - NEW DATA! (Score:5, Informative)
The reason ?
Odd harmonics vs EVEN Harmonics !!!!
Odd harmonic overtones sound HARSH to human brains and are an unwelcome side effect of all solid state electronic amplification.
That was new data in the 90's that this ancient speech being discussed had no idea about.
Valve amps (the original name for tube amplifiers) are basically voltage driven, so when they distort, even-order harmonics are produced (2nd, 4th, 6th, etc...) while transistor amps are current driven and produce odd-order harmonics (3rd, 5th, 7th, etc....)
I cannot believe at the time i posted this i am still the only one to point this out.
All those years of subscription to The Absolute Sound taght me at least why tubes were better and an oscilloscope visibly points out the harmonics.
Re:Odd harmonics vs EVEN Harmonics - NEW DATA! (Score:3, Interesting)
Bipolar transistors are controlled by current. MOSFET's are controlled by voltage. Most reasonably modern high-power solid-state amps use MOSFETS in the output stage.
Oddly enough, some seem to think that bipolar transistors sound better than MOSFETs.
Tubes = distortion (Score:5, Insightful)
Some distortion sounds better than other types. But in the end, you are still getting a signal that is not reproduced faithfully.
(As an aside, modern MOFSETs produce even-order harmonics in an overload situation, just like tubes. This is opposite earlier IC-based gear that produced odd-order harmonics, which are much harder on the human ear. I think this is what the linked talk is going on about. I might also note that audio technology has grown by leaps and bounds since the 70s.)
If you like the "warmness" of a tube, then grab a tube preamp and a modern amp and you can now have the best of both worlds.
The "Audiophile" business is chock full of snake oil, even moreso than many others. $1000/ft "de-ionized oxygen-free" cables? LOL.
History Lesson: Phase Linear & Carver Amps. (Score:4, Insightful)
Typical solid state amplifiers have increased in power an headroom to the point that you are unlikely to want to listen to them at clipping.
It is certainly true that some people like the coloration introduced by tube amps. Guitar players routinely treat tubes as musical instruments by overdriving them.
Another (non-disjoint) set of people enjoy the coloration and noise of vinyl recordings.
The bottom line is that you can make a digital recording of your favourite vinyl/tube/whatever golden-ears setup, and be unable to distinguish it from the original in controlled A/B comparisons.
If you want to color your music, use tubes. If you want high fidelity, don't.
louder is not better (an anecdote) (Score:2, Interesting)
On Fark (Score:3, Funny)
How is this news? (Score:2)
They Don't Mention....... (Score:2)
"Better" vs. "Accurate" (Score:3, Insightful)
As far as the article - the THD levels (3% to 30%) aren't unusual for 60's era equipment. Since the late 70's it's no big trick to design "transistor" equipment that has essentially unmeasurable THD even approaching rated power levels - it just requires lots of feedback and a better power supply than most consumer equipment has.
There isn't much point in observing that tubes clip waveforms more softly when you can design solid state equipment that never clips at all. However, some people may prefer the distorted output of tube amps to the accurate output of solid state amps.
I still use tube amps for guitar ("sounds better"), but all solid-state for playback ("more accurate"). Fender (and probably others) now offer DSP based amps that will emulate tube amplifier sound - haven't ever tried them, so I'm not sure how good they sound.
they are warmer sounding (Score:2)
Not scientific but to my ear the high end with tubes has more clarity and definition to my ear.
strings, amps, true differences (Score:5, Insightful)
Some people (Angus Young of AC/DC, for example) swear by using new guitar strings, replacing them as soon as they get a bit worn. Others (e.g. Neil Young) won't use 'new' ones and actually have roadies break their strings in before they will play them.
(Angus also likes to use no effects pedals, while Neil loves effects. Just picking those 2 at random 'cuz I read up on them. Which is better-- straight guitar or with effects?)
Which is "better"? The answer is 'whatever gives you _your_ sound'. You like tubes, go for it! Solid state give you what you want, more power to you!
With amps, people get distracted by engineering gobblygook, but the truth is: to get 'killer tone', you need to choose your own mix. Guitar choice, strings, amps, heads, effects, EQ, there's a fucking reason you can buy a million and one of each-- there is no one right path!
You can't define sound. It's experiential*. There's no one right set of gear. There's no one best type of music. There's no one best musician. There's no best album of all time.
Freebird! Freebird!
*(sonically, you can usually define 'sucky' due to poor audio quality, but when you get into 'good' you start getting into taste as much as specs)
Blaw Blwa Balw Blslsljeuiy (Score:3, Informative)
As a Bass Player who has been in on more than a few sessions, I can tell you that my ears tell me that there is a difference between a nice Mesa Boogie or classic tube amp, and a straight transister amp.
I own both types. Both have pluses and minuses. But for bass, you can not beat the tube sound, even sythetic tube is just not the same, the ear knows.
Why Choose? (Score:5, Interesting)
~jeff
Not news: plus links to some good audio-amp books (Score:3, Insightful)
For example, some really good explanations and designs relating to this topic are given in a series of books by John Linsley Hood, findable at http://engineering-books-online.com/search_John_L
(Some knowledge of analog(ue!) audio electronics is needed to follow some of the points fully.)
IMO some of the information can be summarised like this: Very good amplifiers can be made both with vacuum tubes (or valves!) or with transistors, and very good examples of each tend to sound alike. Some quite subtle distortion issues can arise in transistor amplifiers, from details of the way in which high-frequency rolloff is applied to obtain feedback-amplifier stability against unwanted high-frequency oscillation.
In an earlier life (!) I built/modified some audio amps to JLH's designs, I also decided to choose commercial amps on the basis of checking their design circuitry, (where the manufacturer would agree to disclose it, which not all did), to see if their hf stability circuitry is applied in the way that JLH's design criteria indicate that they should be. Not all high-price audio amps do that.
With examples that do, I found that my ears can (or at least they used to be able to) distinguish what I would call an unforced, neutral, clean sound quality, with undistorted transients, specially audible (for example) in the way that a triangle-sound is left clean and un-fuzzed, and in the way that the sounds coming from the mass of a band or orchestra emerge as distinguishable individuals rather than as a fuzzy sound-mass. Of course, good recordings and input signals
as well as good speakers are needed for any such subjective aural tests, and naturally any amp suffers to some extent if overloaded. It needs also to be noted that the standard that is met by an overloaded tube amp but not by an average overloaded transistor amp is a standard that tolerates a very high and audible level of certain kinds of distortion.
-wb-
We already knew this (Score:4, Insightful)
The only thing you really need to know... (Score:5, Insightful)
Any effect, such as that of a tube amp, a vinyl player, or whatever else makes music better for you, can be emulated. Any distortion, clipping, overloading, whatever.
Audiophiles live in a reality distortion field which makes Steve Jobs (Apple) look like a kindergarten magician.
Call me when TV has the same luxury problem. "This here looks completely real, but some people claim they can see the difference between this and reality. Those videophiles are crazy!". It'll take a lot more than HDTV to do that... and in 3D of course
Kjella
That paper is from 1972 (Score:5, Informative)
This whole phenomenon is well understood today. You can buy a little "tube amp emulator" [samedaymusic.com], with emulations for famous tube amps. Choose your own harmonic distortion. There are product lines of amp modellers. [wholenote.com]
Most of the trouble in audio today is not tube vs. transistor vs. digital. It's from artifacts introduced during compression of the dynamic range. The real problem is the car audio listening environment, which is noisy. Radio stations need to sound good in cars. This led radio stations to compress their audio into a narrow dynamic range. People got used to this. Then, when cars got CD players, CD mixes began to be compressed like car audio. ("You don't want your record to be the softest one in the changer"). Now, most popular music is so compressed that musicians have totally lost the musical use of volume. You can't have a soft passage; it will be pumped up. Sharp attacks are clipped, so that tool has been taken away. The end result is popular music that has no texture. Background music.
The debate misses the point for most (Score:3, Insightful)
The problem with the valve (tube) Vs. silicon debate is that it doesn't relate to the 'average joe' who listens to snatches of music 'on the go' on their radio, CD or MP3 player, probably while doing other things such as sitting on a train, driving their car or working on their PC. Under these circumstances the listener isn't focusing solely on the purity of the sound reproduction but on the 'background noise' that the sound provides with a familiar or favourite tune.
Naturally, a true audiophile will have their own acoustically perfect listening room, will slip on their favourite headphones or sit in front of their favourite speaker system and will wait for their tubes or FETs to warm up - heck no, they'll never turn them off in the first place! Under these circumstances the audiophile will buy whatever they believe will do their 'listening pleasure justice' - tubes, FETs or hybrids. Fair enough - those with the money can do what they want, but the vast majority will be happy with their Sony, Panasonic, PC system etc. and won't give a stuff what actually makes the sound come out the speakers.
In a similar way, the recording industry's attempts to thwart the 'for personal use' pirates with copy protection mechanisms makes be laugh-if I REALLY want to make a copy of something 'protected' and I can't be bothered to find out where to download the latest crack or workaround off the 'net then I'll simply hook up a stereo mike in front of my speakers and make a copy that way - naturally, this won't give me a 100% perfect audio copy but that's NOT going to bother me if all I want is a 'rough and ready' copy.
izotope ozone (Score:4, Informative)
The plugin clearly demonstrates that the distortions (when used with care) can really enhance music. It also demonstrates that you can get the same effect by processing the sound digitally instead of with tubes. Izotope ozone actually goes way beyond what traditional tubes can do because it doesn't have the physical limitations.
Of course most commercial rock and pop music is processed and filtered in the studio before it is put on cd whereas older music (or indie records) tend to sound better when played back on equipment that adds the distortion effects. Of course the amount of distortion is a matter of personal taste and I find that I enjoy my music more with a little bass compression and a bit of sparkle in the higher ranges. Studios tend to optimize for cheap equipment (i.e. it has to sound nice on cheap radios) so you can gain a lot by adding some distortions.
You can also use sound distortion to compensate for lossy compression or lousy speakers. Just boost the bass digitally for the frequency range that your subwoofer can actually handle; add a little sparkle to compensate for loss of higher frequencies during the mp3 compression; add some overdrive on a guitar track. Distortion is not necessarily about reproducing sound as it was when it was recorded but about making it sound as nice/pleasing as possible. Much of the distortion effects in sixties equipment is deliberate and not accidental. Electrical guitars are a good example of how distortion can be used to produce a wide range of sounds.
A trick of the trade: Louder *can be* better (Score:5, Interesting)
HOWEVER, As someone with (some) experience in audio production, I should mention that when a signal is compressed and then amplified, this can help increase the detail in weak signals. This is nothing new; in old vinyl recordings, especially of classical orchestras (music with a lot of dynamics) the sound engineer had no choice but to apply some compression to the result.
For digital audio, it is easy to maximize audio levels with any wave editor: Almost every one of them has a "normalize to maximum" function. No harm in that; it allows to maximize the level without clipping it. Typically, gives a result with average sound level of 3-6 dB below 'professional' CDs which is so common to find in 'amateur' demos. The best way to punch up the volume further is by turning it up on the amplifier. However I found my customers wanted the CD itself to be louder. Here's how I did it without causing any clipping.
By itself there is no problem of punching up the level another 3-6 dB, but if you're going to do this by simply increasing the amplitude, the signal *will* clip and sound horrible. Instead, apply a very light distortion over the signal (in cooledit 96 it used to be under the Special menu, draw a slightly bent curve, amplifying softer signals a bit more than the louder ones), essentially mimicking what a tube does. This will increase the average level of the signal, increase perceived definition of the signal, but will not cause clipping. It will color the signal, but in a pleasant way, just like tubes.
This technique does however have two downsides: 1. Because it does color the signal, it may mess up with your carefully balanced mix and equalization. 2. when used to excess, it may still cause unwanted distortion sound. Use your ears to proof the final result. As with all audio matters, don't go for bullshit. Most importantly, let your ears be the judge. And did I mention to use you ears to judge the final result?
Why not mag-amps? (Score:5, Interesting)
I wonder why this technology quietly died.
Nomination for Troll of the Week (Score:4, Insightful)
Clueless, disingenuous or manipulative? I couldn't tell. But it's not exactly helpful in forming a well-considered mindset about audio design.
Here's my 3-bullet take on the weird juxtaposition:
* The older paper (as well as others quickly linked to) talks about how studios risked distortion by pushing amplifiers past design limits in order to escape tiresome, easily-heard tape hiss. In the 30 years since, the dynamic range of amplifiers has improved (less likelihood for over-the-edge conditions); metering and sound checks have gotten easier and faster, leading to fewer mistakes; and (analog) tape hiss, when it's an issue at all, has also dropped further down the list of concerns. Why is this archive paper relevant without those differences mentioned?
* The second-linked article vents frustrations that even live music is intentionally garbaged up by the creators. The sound is intentionally manipulated to sound "louder" which also makes it SOUND AS IF it was produced by over-driven equipment. That's the artists' prerogative, and the critic's job to carp about. Nothing to see here, folks, except that it interestingly links to
* a previous in-depth analysis of the Dark Side of the Moon SACD that details differences between formats that must have been driven by perceived preferences of listeners, not the formats themselves. Implicitly, some engineers seem to believe that CD listeners prefer LOUD while SACD listeners like "clean," because that's how they manipulated the two formats differently. For CD listeners, they clipped the sound INTENTIONALLY, and differently from any faults of the electronics, in a way that's unnecessary for the CD format. Clipping produces ugly noise on loud spots, but makes the recording sound "louder."
One might guess that engineers aim for the "cleaner" effect on vinyl, too. (Not too many vinyl fanatics risk installing their systems in cars, so they can groove while cruising along I-5, and probably not very many SACD systems, either.) And it's also not too much of a guess to assume that vinyl listeners are about 10X to 100X more likely to use tube equipment, which the owners have selected because it sounds (to them) more the way THEY prefer.
So this attempt at stoking flames under the War of the Formats (Audio Division) can be seen as having nothing to do with "Tubes vs Transistors," as titled. Rather, it oughta be, "my format Rools and yours Sux" or something more appropriate to the information that it provides to the topic. Absent the 2+2=17 faulty logic, the articles actually seem to show that engineering allows whatever "sound" the seller wants to feed the consumer, without any objective "quality" standard at all.
I propose "Troll of the Week" balloting to allow us to heap opprobrium on such posts. This shouldn't even make it on a slow news day. I'm all for vigorous discussion on "stuff that matters" but articles that encourage senseless flame wars don't exactly further that goal.
Tube Audio Preamp in Motherboard (Score:3, Interesting)
This is why I listen to LP's... (Score:3, Interesting)
You can make both tubes and transistors sound clean or dirty (distorted), and they do sound quite different when dirty and each is "appropriate" in different contexts, but having whole albums sounding dirty causes ear fatigue and it just sucks.
Does anyone else find it ironic that LP's were recorded with a substantially greater dynamic range than is used on current CD's?
In the event of nuclear war ..... (Score:3, Funny)
the debate rages on (Score:3, Informative)
So we're back to silicon vs. vacuum. Now, in the 1960s and 1970s, transistors were still just expensive enough that they were still competing with valves, and a tranny amp from that vintage -- if it's been fitted with new capacitors, which degrade over time -- will sound as good as a cheap valve amp from the same vintage. It had to, because the competition was there. Today, valves are strictly in the realm of esoterica, and modern IC / transistor kit doesn't have to try to compete with them.
But it's a highly subjective area, and "scientifically perfect" reproduction (identical waveshapes, just different amplitudes) is not necessarily right for the ear. There is little doubt that the distortion characteristic of transistors is harsher than that of valves. This is because, by trying to be "scientifically perfect", they hit the supply rails easily. (Recall that valves use supply rails between 100-500V and require transformers to match to low-impedance loudspeakers; transistors are driving the speaker directly, 20W RMS at 8 ohms is 36Vp-p or +-18V). So with valves, there is more headroom. Deliberate slew rate limitation also helps, by giving a different type of distortion (never quite making it, which gives even harmonics, rather than trying to overshoot and maxing out, which gives odd harmonics). Odd harmonics are reckoned to have a harsher sound than even ones. In fact, modern op-amps, with almost DC-RF bandwidth and consequently slew rates in volts/nanosecond, are as harsh as you'll get.
Bottom line, if somebody spent a fortune on an amplifier -- beyond the point where the Law of Diminishing Returns sets in -- they must think it's good, otherwise they wouldn't have bought it. And there's unlikely to be any way of convincing them any different.
BTW, the first commercial use of transistor power amps was in juke boxes. My dad has a 1962 Seeburg with a 25+25 watt power amp (transformer coupled, has 100V line outputs, C/T to chassis so you can easily arrange mono speakers, taking 1/2 of LH signal plus 1/2 of RH signal in series) and also a power oscillator to run the motor at 45RPM (it does 33rpm on 50Hz so it needs 68Hz for 45RPM; it actually cheats by starting at 33RPM then switching to 45RPM, so it doesn't need to cope with the starting surge. A stationary motor looks like a short circuit). I don't think this was the first juke box to have a transistor amplifier, though, because I've seen one in a 1957 Wurlitzer (but this may have been a retrofit).
And here's proof: (Score:3, Interesting)
Similarly, synth manufacturers have started putting tubes into their products - for example, the recently released Korg Triton Extreme uses tubes to process the sounds. Considering this has an extremely powerful DSP engine, it's doubtful the effect could be used digitally.
That said, some manufacturers tend to use tubes as
Re:Counteracting "louder is better" (Score:3, Insightful)
Patient: Doc, it hurts when I do this.
Doctor: Don't do that.
Or, maybe you could get a really tiny tube amp, and listen at normal volumes, and hope that all the "pleasant" distortion of the tube amp in overdrive cancels out the overmodulated recording.
Re:why DSPs can never equal tubes (Score:3, Informative)
Of course, this doesn't make the anal
Cheap answer (Score:3, Informative)
Or you can get silly about it and emulate the valve clipping and noise in each stage of the amp [bluetoneamps.com] instead.
What? (Score:3, Informative)
Sorry, but that whole rodomontade just got funnier and funnier as it went on, and that last sentence cracked me up.
Having studied microwave transistor structures in both Si and GaAs, I can tell you that at audio frequencies, "intertia" of electrons, perhaps you want to mean dispersion or diffusion current veloc