Tubes vs Transistors: An Audible Difference?
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."
The recent trend in "louder is better." Did I just read that? The recent trend? Since the first real Rock and Roll music appeared approaching, 60 years ago now, louder has been better. That's a "recent" trend?
If part of being better includes consistanly sounding the same, then glass audiophiles have to tuck their tales between their legs. Tubes wear out. As they wear out, their sound qualities change. Who's to say that the 'changed' sound is desireable? Maybe it's an improvement...that's the problem; it's not cosistent.
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.
How does a speech from the 70s, discussing how better "behaved" tubes are, have relevance today? Transistor technology has had 3 decades to grow into a more stable, mature platform for audio, and we understand a great deal more about the nature of sound and the equipment producing that sound.
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?
Better for whom? The average listener won't be able to tell the difference, this is like how theres a few nutbags such as myself that still enjoy listening to vinyl. It can just sound better sometimes.
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.
Presently here, but not there.
This discussion is a valid one to have, regardless of how many time's it's been brought up, because the aspects of what makes sound pleasing or interesting have little to do with a list of output-section distortion numbers.
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.
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.
That's it. I'm no longer part of Team Sanity.
Bob Carver did this already. If I remember correctly, it's the increaed resistance from a tube amp using output transformers that creates the 'soft' sound that characterizes glass audio.
Carver created a solid state amp which pretty much mimicked a $10K tube amp and no one could tell the differencec in blind tests.
I am shocked that this old crap has no annotation from the 1990s when phychology tests proved tubes sound more appealing than solid state op-amps.
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.
Any unintended (i.e. can't shut it off if you want to) effect on the audio is distortion. Period.
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.
Natural != (nontoxic || beneficial)
It seems like you have listened to the 1970s-era solid-state proponents a bit too much. The "nice sounding distortion" myth is just that.
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.
I love reports that tell us what is musically "better". It reminds me of the debate over, of all things, guitar strings.
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)
A.
~jeff
Parent poster is correct. Several products exist which attempt to use DSP to mimic the sound of tube amplifiers, almost all of them in the guitar effects realm. None of them are yet there. They sound a lot LIKE a tube amp, but they don't capture it all. CAN they? Probably someday. But not yet.
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.
Ce n'est pas un vrai mouvement de robot!
DSP CAN NOT give you the same characteristics as a tube.
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.
Trees can't go dancing
So do them a big favor
Pretend dancing stinks!
The problem with this is you end up with horrible range 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, my stereo dac becomes the limiting factor. When you turn up crap like this, 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
[Fuck Beta]
o0t!
...is that we have achieved amplifiers based on transistors that are more accurate than human hearing. Once you achieve that, there is no point in having anything else.
:)
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
Live today, because you never know what tomorrow brings
This whole phenomenon is well understood today. You can buy a little "tube amp emulator", with emulations for famous tube amps. Choose your own harmonic distortion. There are product lines of amp modellers.
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.
I wholeheartedly agree with the article discussing the Rush album; those waves *were* severly clipped, and whoever mastered that CD should be very very ashamed of themselves (although it looks like the clipping happened in several stages, not just in the final mastering) for forgetting what matters the most in audio production: Quality control of the product by using their ears. Californication of the Red Hot ChiliPeppers lacked the same final check, it's horribly clipped as well.
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?
Visit http://ringbreak.dnd.utwente.nl/~mrjb/growingbettersoftware to download your free copy of the book
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.
Shop as usual. And avoid panic buying.
My old ~1987 Proton D940 uses magnetic amplifiers. The little reciever/amp clocks in at around 40lbs. Sounds better than almost everything available today.
I wonder why this technology quietly died.
Get a free ipod.
On a day when the real-world news is rife with examples of how faulty information processing has lead to multiple thousands of deaths, Slashdot dredges up issues with studios' technology from the 70's and claims they apply to consumer choices of today. Of course, in the fine print, NONE of the boundary conditions that are pushed, accidentally or intentionally, are similar.
...
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.
"Inquiring Minds Want to Know!"