Tube gear obsolete??
- Thread starter DaveyF
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I find the colorations of solid state to be a distraction and not really faithful to the music at all. I concede that if improperly designed tubes will impart coloration as well. IME its all about topology. Tubes are often cited for the overly warm 'tube sound' which has to do with the 2nd harmonic. But that is easily eliminated by the topology and the result can be a very neutral presentation, but lacking the usual solid state artifacts.
As I mentioned previously, if I could design a SS amp that was really neutral and musical I would abandon tubes in a heartbeat. But I can't and no-one else seems up to the task either (or that amplifier would already be quite well-known, instead all we really know is argument). The fact of the matter is if transistors really were better, tubes would not exist. It really is that simple.
After reading this this morning I felt a breath of fresh air descending down my spine.
Ralph, you mentioned above; "I concede that if improperly designed tubes will impart coloration just like solid state do."
My question: If properly designed, can tubes achieved faithfulness to the source (music), without adding coloration?
And how general and relevant it is today? ...On average, and from most audio tube gear manufacturers.
Plus how consistent and reliable are all the components, including matched tubes? ...And their longevity.
I am also interested in Ralph's response to your questions. I have a feeling I know the answers, but let's see what Ralph has to say.
Actually you have paraphrased my comment but I don't think it will alter things too much-
The basic answer to your question is 'yes'. The problems we face regarding 'faithfulness' are not in the tubes but in the media and the loudspeakers. Of those two, the media is the more at fault. I do feel that the closer we can get to the musical experience the better- its more inspiring, so its good for business. So it is 'relevent'.
Your basic ST-70 is going to impart a coloration regardless of the parts or tubes used. The problem is the topology. When you mix single-ended circuits with push-pull you can predict a certain distortion signature- in this case a 2nd and 5th harmonic will show up that really does not need to be there.
As far as consistancy that does depend somewat on the tubes involved but we all know that. I have some Neumann U-67s that have the same tubes in them that they had 30 years ago and they still test fine. So application has a lot to do with consistancy. I think there are a lot of manufacturers that are in it for a buck, which in this field is the wrong motivation if you really want it to perform. Seeing how close we can get to the real thing is a better motivation IMO. As a result there are a lot of manufacturers that do not take advantage of the properties of the tubes that they use. Its been my experience that triodes seem to maintain their performance more consistantly than pentodes- 2000 hours is a reasonable lifespan for a pentode power tube but a triode might go 10000 hours. A lot depends on application though, however most pentodes seem to also be in class AB circuits where triode power tubes are more often in class A circuits that one would think would be harder on the tube....
Did that answer the question?
To those two, I would also add the room. BTW, this does seem to re-enforce the front end importance as well, R toR with master tape being preferable. ( At present, even though I am not in RtoR, IMHO it is the best available source).
Ralph, another question here...do you think that the triode's ability to throw off more or less heat than a pentode design has anything to do with their extended longevity?
Yes, I mentioned the room effect in an earlier post. A good sounding room is really helpful...
RtoR is great but direct lathe cuts are even better. So far that is the best media, however ephemeral. QRP (Acoustic Sounds) has done some exceptional work on their pressing machines, and so can produce pressings that seem as quiet as the original lacquers (which easily rival digital for low noise). So the LP continues to evolve and improve...
A triode tube has similar surface area to a pentode so that is not the reason for longevity. I think that has more to do with their simplicity- there are less things to go wrong. Whatever it is, they are consistent about it
The basic answer to your question is no.
Now, If the inherent coloration from a tube amp "fixes" the source by making it sound more "live" to you - as it often does to me - that's fine.
But let's not pretend that the best tube amps are as faithfull to the input source as the best SS amps, because it just ain't so.
I don't care if your output transformer is spun gold wire on a depleted uranium core hand wound by 70 virgins, it's still a transformer - the nastiest componant one could possibly ever place in an audio signal path.
That depends on what you are trying to be "faithful" to - the input signal, or the original performance.
You cannot "improve" an input signal without altering it in some way.
Some like how tube amps alter the input signal and some do not, but it is altered none the less.
Did you forget Ralph's amplifiers are OTLs?
And by what measure can you say with absolute certainty that ss doesn't introduce it's own colorations? And what makes a transistor better than a tube when it comes to reproducing music? Transistors are great for computers, maybe not so great for music.
If your conclusions are based on distortion, then we know what the couple of gen of ss gear sounded like-as much as we would like to forget. And if you go back in this and other threads, you'll see Ralph has raised questions about what types of distortions our ears are sensitive to. Face it. Both alter the signal otherwise we'd have live music in our rooms.
It is up to the recording engineer to be faithful to the original performance. It is the task of playback equipment, unless used as a monitor, to be faithful to the recording. You and I agree on one thing- that output transformers are a problem, although I find that the best transistors seem to be taken to task by a properly designed tube amp that uses them. I never developed the talent for transformer design and have stuck to OTLs.
With regards to your other comment, I think the problem is an assumption that the test tones and signals can reveal all there is to know about an amplifier. The problem is that our test regime does not take into account human hearing perceptual rules. Essentially we don't measure the right things. The result is a SS amp can look good on paper and sound bad, a lowly tube amp can look bad on paper and sound fine. This is because the tube amp can more closely follow the perceptual rules, which so far are not showing up in our tests. When we get transistor amps to follow those rules as well as tubes we will also have a transistor amp that sound as good or better than tubes and is more 'faithful'. Until then we have the unending argument.
With regards to that argument its apparent, Larry, that you got into this a little later than me, and did not read the link at my early post. Here is is again:
http://www.atma-sphere.com/Resources/Paradigms_in_Amplifier_Design.php
The Power Paradigm is a means wherein an amplifier of high output impedance can also have a flat, uncolored presentation.
spun gold wire on a depleted uranium core hand wound by 70 virgins
"output transformer is spun gold wire on a depleted uranium core hand wound by 70 virgins" from Dirty Larry
I want to know where I can buy these transformers. Do they make a 5K primary with a 16 Ohm secondary tap?
zz
"output transformer is spun gold wire on a depleted uranium core hand wound by 70 virgins" from Dirty Larry
I want to know where I can buy these transformers. Do they make a 5K primary with a 16 Ohm secondary tap?
zz
I hate to say it, but the above bolded text is pure nonsense. You are never going to have a flat, uncolored "presentation" from an amplifier with a high output impedance into the majority of all loudspeakers known to man whose impedance changes across the audio bandwidth. I read your paper you provided the link to and found it to not be technically informative and directed to those who are easily swayed by pseudo-technical papers that reinforce the belief system they already have.
I for one find your distinction between the "Voltage Paradigm" and the "Power Paradigm" to be very misleading. P= I x E no matter how you cut the mustard. Tubes obtain their watts from high voltage and low current and SS obtain their watts from low voltage and high current. Your observation that speakers require power and tubes put out power is sort of funny. Of course tube amps put out power, but are we trying to say that SS amps don't put out power? At the end of the speaker terminals of any amp be it SS or tube, there is power coming out that is measured in watts. We can't change Ohm's law no matter how some wish to twist it around.
MEP, you might want to recant, as your opening comment is a logical fallacy known as a Strawman (as I don't make any such claim in the article). An argument based on a logical fallacy is by definition false. I didn't make this stuff up- it has to do with history (nor is anything about distorting Ohm's Law which as we both know is inviable). I can give you plenty of examples and some were in the article. However you might want to google 'Fisher A-80 amplifier' but I have done it for you:
https://www.google.com/search?client=ubuntu&channel=fs&q=fisher+A-80+amplifier&ie=utf-8&oe=utf-8
The first hit is a YouTube video image of the damping control of the Fisher amp. It was a current and voltage feedback control. Full counterclockwise it is labeled 'Constant Voltage' and full clockwise it is labeled 'Constant Current'. At Noon (where the current and voltage feedback cancel) it is labeled 'Constant Power'. So if you are to call me out then you have to explain the existance of that amplifier. FWIW I have made measurements as have independent 3rd parties like Soundstage.com that show that the constant power phenomena can indeed be found in a tube amp with no feedback.
I have to guess that I must be a little older than you as I remember seeing stuff like that Fisher. It was not the only amp with that kind of control. EV made them too. The problem back then was that there was no way to know the voltage/power response of the amplifier as output impedances were all over the map as were speaker impedances. If you see a speaker (typically horn) from that era it will likely have a tweeter or midrange level control. Those controls were not there to adjust the speaker to the room, they were there to adjust the speaker to the response of the amplifier. You are apparently younger than me so you are excused in not knowing this. The Voltage Paradigm was proposed by EV and Macintosh as a method of getting around this adjustment problem- as a means of insuring flat frequency response when you hook up an amp to a speaker (I'm pretty sure I mentioned that in the article, now I am wondering if you actually read it). The problem is that a different problem was introduced, one that has been with us to this day. That is the problem of brightness and harshness. I know I mentioned that, so now I am pretty sure you didn't read the article all that carefully.
I used the word 'paradigm' for a reason. That reason is that people that operate exclusively on one platform of thought (in this case you) will regard thought outside of that platform as blasphemy. It was not to sway weak minds. I have a copy of the Radiotron Designer's Handbook which is a large and historic tome, published in the early 1950s. In it there is a formula for output impedance, which when used yeilds a number that is within 5% of the values I measure in our amps. But the technique I use for that is the older one- that of finding out what the output impedance of a black box is. You may remember the technique from college. I do- that is why I used it.
But in these modern 'post-power' days (about 1965 to present) this technique is no longer used. Nowadays a more typical measurement is to apply an AC voltage to the output of an amplifier and discern what happens to the amplitude of that voltage. Its not a measure of the output impedance of the circuit so much as it is a measurement of the servo gain of the circuit. Also nowadays we have two ways of expressing how loud a speaker will play with a given amount of input. Sensitivity (2.83V/1 meter) and Efficiency 1 watt/1 meter. Now why in the heck would we have two such measurements?? The answer is that the efficiency measurement comes to us from tradition. Sensitivity comes to us from much later- it was the 1980s before it came into common use. If you want more examples I can provide them.
However I have pointed to 5 examples that show that there is a historic basis for my article. How many do you have that refute them? To do so they must also be historic- things we can point to of substance.
Now if we want to do that math that is also easy. The Power formula and Ohm's Law are simple equations. How exactly do you propose to apply them in such a way that they demonstrate that what I said is nonsense? Trust me on this one as soon as you can come up with an example I will be also able to show where the flaw exists in your assumptions. That is not because I am being arrogant (although right now I will concede that) its because I have investigated this for years and have tried to get 'experts' to disprove me. Most have come on board FWIW...
Ralph-I have nothing to recant. I don't know how old you are and you may be older than I am. I will turn 58 in August so I while I was born at night, it wasn't last night. You mentioned the Radiotron Designer's Handbook. I'm familiar with it as I own a copy. You alluded to me not really reading your article several times, but I did. Do any of your amps come with a dampening control? I didn't think so. Dampening controls typically increase or decrease the amount of negative feedback. There are several tube amps on the market that come with feedback controls where you can dial in less or more feedback to suit your tastes with all "purists" desiring zero negative feedback while most push-pull tube amp designers use some amount of negative feedback. Although some Lamm amps come with a feedback control, if memory serves me correctly, Lamm doesn't really recommend monkeying around with it.
There is no way around the fact that tubes are high-impedance/low current devices compared to SS. That is why the majority of all tube amps on the market use output transformers to step down the impedance and raise the output current. OTL amps of course have no output transformer so you find yourself in a different box where you are now forced to connect a bunch of output tubes together in order to try and lower impedance and raise the current. There is a reason why OTL amps like higher impedance speakers and why power falls off as impedance drops. Please tell me one tube amp on the market whether it's OTL or transformer coupled that is going to measure "flat" into the majority of all loudspeakers currently available. To my knowledge, there are none. We can argue whether we like the sound of watts created from high voltage and low current better than we like the sound of watts created from low voltage and high current, but we can't argue that P = I x E. You can argue that you like the sound of tubes better than the sound of SS (and I have owned tube gear all of my life), but you can't argue that a tube amp will measure flat into a loudspeaker load. And no Fisher A-80 is going to change that.
Why don't you present some measurements of your amps taken by someone reputable like JA from Stereophile and show us how flat they measure into simulated speaker loads? If your amps measure flat into simulated speaker loads and the measurements are taken by someone that we have all heard of and respect like JA, I will recant. Until then, I stand by everything I said.
There is no way around the fact that tubes are high-impedance/low current devices compared to SS. That is why the majority of all tube amps on the market use output transformers to step down the impedance and raise the output current. OTL amps of course have no output transformer so you find yourself in a different box where you are now forced to connect a bunch of output tubes together in order to try and lower impedance and raise the current. There is a reason why OTL amps like higher impedance speakers and why power falls off as impedance drops. Please tell me one tube amp on the market whether it's OTL or transformer coupled that is going to measure "flat" into the majority of all loudspeakers currently available. To my knowledge, there are none. We can argue whether we like the sound of watts created from high voltage and low current better than we like the sound of watts created from low voltage and high current, but we can't argue that P = I x E. You can argue that you like the sound of tubes better than the sound of SS (and I have owned tube gear all of my life), but you can't argue that a tube amp will measure flat into a loudspeaker load. And no Fisher A-80 is going to change that.
Why don't you present some measurements of your amps taken by someone reputable like JA from Stereophile and show us how flat they measure into simulated speaker loads? If your amps measure flat into simulated speaker loads and the measurements are taken by someone that we have all heard of and respect like JA, I will recant. Until then, I stand by everything I said.
Yes it did, and very well too, 'air' a bunch (thx lot)!
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Ha! ...Just the total opposite of Ralph's earlier reply.
Now, If the inherent coloration from a tube amp "fixes" the source by making it sound more "live" to you - as it often does to me - that's fine.
But let's not pretend that the best tube amps are as faithfull to the input source as the best SS amps, because it just ain't so.
I don't care if your output transformer is spun gold wire on a depleted uranium core hand wound by 70 virgins, it's still a transformer - the nastiest componant one could possibly ever place in an
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...This is quite an interesting discussion.
* And yes Mark, I even read your posts. ...Of course.
* And yes Mark, I even read your posts. ...Of course.
All depends on what is the criteria to check the "faithfullness". If you use the famous null test criteria, without any weighting of the residuals, or if you do some specific weighting as Ralph suggests in his posts you will get different answers.
Mep,
IMHO the key point is here: (Quoting Atmasphere site)
Loudspeakers that operate under Power Paradigm rules are speakers that expect constant power, regardless of their impedance. Examples include nearly all horns (currently the Avantgarde Trio is the only known exception), ESLs, magnetic planers, a good number of bass reflex and acoustic suspension designs. Horns, ESLs and magnetic planers do not get their impedance curve from system resonance and so benefit from a constant power characteristic and indeed, many of these speaker technologies are well-known as good matches with Power Paradigm amplifier designs.
You have to understand that not all speakers operate in this way. It is why when referring to OTLs I always specify "when used with adequate speakers".
Fransisco-Please define "constant power" as it relates to an amplifier playing music through a speaker.
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