Thanks to everyone who posted here - there most certainly is more to this than meets the eye, and ear! |
,
Live music is all about inducing emotions,
involvement and simply being fully engaged. That's the joy of music's
ability to communicate. Tubes don't totally equal that live experience but
they bring me much closer than any SS amplifiers I've heard so far (25
years of High End awareness).How can something be considered
"accurate" and fail to be involving? The more effectively a
component can mimic live sound the more involving it will sound. This is
what I call "natural" sound or realism. In my personal discovery,
SET amplifiers have pushed me the furthest in this beautiful direction and
there's no going back. Everyone must find what works best for their needs
and ultimate satisfaction.
Charles, |
Zd- say again? Just that last paragraph - not sure what you mean. |
"That's definitely true that in the studio it's processing the signal - but at home, tube amps are often doing the same thing. It is a form of distortion. Not all tube based systems distort this way, but I do see lots of listeners using underpowered amps for the speakers they have."
Just to clarify, I was talking in general theory as to what is expected of a home stereo. Reproduce the original event as accurately as possible, etc... You've heard it all before. I wasn't suggesting that everybody approaches their system that way. There's the 2 extremes, and most people are somewhere in the middle.
"Tubes are a great way to emotionally get close to the music - I think of tubes as a way to create an illusion that performers are in the room with you - but I never think of this as accurate or neutral - but it can be very involving..."
Why not? When you go see live music, do you expect it to be accurate, neutral and not emotionally involving? lol. I know I do. I want it to sound just like my stereo system at home. |
Orpheus10- I almost skimmed past your post. Most helpful - thank you. |
Atmasphere. Thanks for clarifying Peak vs Av. |
I've said it before, but it bears repeating even if I'm the only one who believes it: Tube amps make you a better person, they display signs of life in their glowing hot little selves, and SS amps that just sit there like a metal lump of "meh" are far less interesting regardless of how they sound, unless they have some sort of fluctuating meter on them in which case I give 'em a pass (no pun intended). A home run amp I heard recently was a Rogers (there are others) that had tubes AND a meter...a goal for all tube amps to strive for. |
That's definitely true that in the studio it's processing the signal - but at home, tube amps are often doing the same thing. It is a form of distortion. Not all tube based systems distort this way, but I do see lots of listeners using underpowered amps for the speakers they have.
Tubes are a great way to emotionally get close to the music - I think of tubes as a way to create an illusion that performers are in the room with you - but I never think of this as accurate or neutral - but it can be very involving...
At home distortion is not the name of the game. Seriously. The ability of a tube amp to reproduce a more realistic soundstage (as depicted in your 2nd paragraph) is because they are better at low level detail which comes from the greater linearity that tubes offer. I've always been perplexed by the universal admission by both tube and transistor camps that tubes are inherently lower distortion, but then tubes are always getting docked for being 'distorted' simply because they sound better. The real reason they sound better is they have less of the distortions to which the ear is very sensitive (specifically higher ordered harmonics) although some designs may have more of the types to which the ear is not. Many recordings are in fact made to present a true stereo image, which means a 3D soundstage with depth and Left-right extension, with everything in between.
20% of full power (I'm assuming that means average power) is a significant % but not outrageous if the speakers aren't crazy-sensitive. Am I to understand that SET owners go into it knowing they NEED to keep this contract if they want to enjoy their sound? If the "SET sounds a lot more dynamic" as it encroaches on this forbidden region, isn't it reasonable to think that SET owners (or dealers or wannabes) might poke through that limit just a wee bit to enjoy the subtle excitement of the extra dynamics? I need to hear this myself to know, but my guess is that doing such a thing might lead to one of those "wow, I never heard THAT before!" kind of moments.
I do see more people using speakers that are less efficient then the SET should really be used with, and they still enjoy the result. But its a simple fact that they are not getting nearly the performance out of their amplifier, simply because they are pushing it too hard. Most SETs don't employ feedback (this has a lot to do with the fact that you can't use feedback to extend bandwidth in a power amplifier, and if you are not really really careful with your timing constants in the feedback loop, the poor high end response of most SET OPTs will really get you in trouble- peaks before the roll-off, unstable operation, that sort of thing. So since feedback is unwieldy and sounds wrong because it rarely can be applied properly in an SET, most designers don't do it. As a result, if you run it over 20% full power (on peaks, not average) the higher ordered harmonics will come into play, causing exaggerated dynamics and harsher sound. BTW once you know that distortion is responsible for a lot of the 'dynamic' quality of SETs, its easier to hear that it is in fact distortion doing it, so by reading this I may have ruined if for a lot of people. Sorry about that. To take this a bit further, distortion is really a problem in all systems, not just SETs or tubes in general. As a result, I suspect that in about 90% of all audiophile conversations, the word 'dynamics' can be substituted with the word 'distortion' without altering the meaning of the conversation at all. For this reason I am careful to use a different word, like 'impact' when I want to talk about dynamic contrast. Too much unconscious stigma with the word 'dynamics'. |
First and foremost, I'm not in the "tube vs SS debate"; however, I will unequivocally state that tube amps sound more powerful, watt for watt, and that's all I'm going to say about that.
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Underpowered amps of either type certainly wouldn't be the fault of the particular design. Operator error seems like the right diagnosis. |
Atmasphere writes ...
"you never want to push an SET past about 20% of full power or else the higher ordered distortion products come into play (when this happens, its usually on transients, and because the human ear uses the higher orders as loudness cues, the result is that the SET sounds a lot more dynamic than it has any right to because the loudness cues are occurring on the transients. You read about this 'dynamic' character with SETs all the time, but its an indication that the speaker used is not efficient enough)."
20% of full power (I'm assuming that means average power) is a significant % but not outrageous if the speakers aren't crazy-sensitive. Am I to understand that SET owners go into it knowing they NEED to keep this contract if they want to enjoy their sound? If the "SET sounds a lot more dynamic" as it encroaches on this forbidden region, isn't it reasonable to think that SET owners (or dealers or wannabes) might poke through that limit just a wee bit to enjoy the subtle excitement of the extra dynamics? I need to hear this myself to know, but my guess is that doing such a thing might lead to one of those "wow, I never heard THAT before!" kind of moments. |
Mesch- Agreed! It's a bit of a circus in a classroom ... fun, educational and full of entertaining surprises.
Zd542, Zkzpb8, Charles1dad & Atmasphere - many thanks for keeping this thread moving forward. |
Most SS based systems I have heard over the years were underpowered in terms of achieving optimal performance not on purpose but for not knowing any better and/or not having many practical and cost effective options available, or people just being satisfied and it just not mattering much.
Same true I suspect with tube amps. It's not that tube amp lovers seek distortion, but rather that it similarly may be even less of a real issue for some due to the more benign sound of soft clipping. |
"That's not the same thing. In the studio, what you're talking about above is signal processing. Its part of the creative process. Playback gear's job is completely different. The idea behind that is to reproduce the original event as accurately as possible. Making your amp distort on playback goes in the opposite direction of that goal. You don't want you home audio system to distort because you want to reproduce whatever is on the recording as best you can. Even if its distortion. "
That's definitely true that in the studio it's processing the signal - but at home, tube amps are often doing the same thing. It is a form of distortion. Not all tube based systems distort this way, but I do see lots of listeners using underpowered amps for the speakers they have.
Tubes are a great way to emotionally get close to the music - I think of tubes as a way to create an illusion that performers are in the room with you - but I never think of this as accurate or neutral - but it can be very involving... |
Want to thank the OP and contributors, really enjoyed this thread. |
Ralph,
That sums up my preference for tubes. The only criteria that matters, the more natural sound quality. |
If anything, the move to tube amps in the last 30-40 years has been for the things that tubes do that are difficult or impossible for transistor amps. I don't see audiophiles that are into tubes doing it for any other reason then they want to get as close to the musical experience as possible.
I really don't think you have to know anything about tubes, how tube amps work or why people use them. All you really have to know to understand that they work really well for music, is that over half a century after they were declared obsolete, they are still around- and we still play them and even the tubes/transistor debate is older than many audiophiles! IOW the economics tells the story! |
"09-25-14: Zkzpb8
From my experience I've seen a lot of tube amp owners who like distortion. Not SET guys with highly sensitive speakers, but the 10-20 Watt tube amp owners who mate their amp with a speaker rated much below 90dB."
I've never heard of anyone doing that. Are you sure they actually wanted the amp to distort all the time and not just prefer tube distortion if the amp distorts?
"A good friend of mine is a recording engineer and he always says "people love distortion"... In the studio throw a tube compressor on - and ''fatten" up the sound - warm things up. It's the same effect when someone uses a 10 Watt tube amp on a pair of speakers that are rated 25 Watts minimum. I see guys do it all the time - they're fully aware of the speaker's specs, and despite the manufacturer's advice to use more power they do it anyway. It's a seductive sound - but the product of distortion."
That's not the same thing. In the studio, what you're talking about above is signal processing. Its part of the creative process. Playback gear's job is completely different. The idea behind that is to reproduce the original event as accurately as possible. Making your amp distort on playback goes in the opposite direction of that goal. You don't want you home audio system to distort because you want to reproduce whatever is on the recording as best you can. Even if its distortion. |
Anyone other than Mapman want to respond to Zkzpb8 posts? |
I get the impression that 4 ohm impedance speakers became the default
load once transistor amplifiers became plentiful and affordable. It could
also be that they are possibly easier to design and build. These designers
realized that if there's a difficult load to drive, just purchase a higher power/
current SS amplifier and the problem is solved. Perhaps higher impedance
speakers are more challenging to implement and designers simply followed
the path of least resistance. Sound quality may not have been the only
consideration for this direction.
Charles, |
^^ Charles, I think human nature is the culprit: the most powerful human motivator being to look good, the second most powerful not to look bad. You fail both of those if you don't understand the difference between power and voltage if you design speakers.
BTW, the Tonian and Ocellia have both used the PHY drivers that I mentioned. I think Tonian has moved away from the PHYs but still makes very easy to drive loudspeakers. |
Hello Al,
Yes I understand the premise that most speakers are designed with the intention of using transistor amplifiers. It seems what Ralph was explaining is their(designers) reluctance (or even rejection) to "recognized" his point as it pertains to tube amplifier -speaker interactions.
Charles, |
Great points by Ralph, as usual, with which I agree. 09-25-14: Charles1dad
Ralph, there's something that doesn't make sense concerning your comments about speaker designers. These designers have to have at the very least a rudimentary understanding of science and engineering. Something as basic as Kirchoff's law has to be easily comprehended and applied. They have the equipment available to confirm that concept and its effect. I just don't understand why you would be met with such resistance to something so plain and fundamental. How do these designers counter your point/position? Charles, pending Ralph's answer, as I see it the key to reconciling that is the fact that the majority of speakers are designed with solid state amplification in mind. And with a few unusual exceptions, nearly all solid state amps (in contrast to tube amps) are designed to provide an output voltage which does not vary significantly as a function of load impedance, as long as the amp is operated within the limits of its voltage, current, power, and thermal capabilities. Therefore, as a consequence of Ohm's Law and the definition of power, while of course not all solid state amps will double their rated MAXIMUM power capabilities into halved load impedances, nearly all of them WILL double the amount of power that is delivered into a halved load impedance (albeit perhaps with some increase in distortion), as long as they are operated within those maximum limits. So when Ralph says: If you have a single woofer and put one watt into it, it might make 92 db at one meter. If you have two of the same woofers in either parallel or in series and put 1 watt into the array, the result will be the each driver will have 1/2 watt on them- and the output will be exactly the same 92 db. ... Note that he refers to an input of 1 watt. If he had referred to an input of a given number of volts, say 2.83 volts (which corresponds to 1 watt into 8 ohms, as he indicated), applying that voltage to two identical woofers in parallel (which together have half the impedance of a single woofer) would cause twice as much power to be delivered as if the same voltage were applied to only one woofer. Resulting (everything else being equal) in a 3 db increase in SPL. And conversely, applying that voltage across a combination of two identical woofers in series (which together have twice the impedance of a single woofer), would result in half as much power being delivered as if the same voltage were applied to only one woofer, resulting in a 3 db reduction in SPL. Basically, the speaker designers Ralph referred to are thinking in voltage terms, rather than power terms. Which is arguably reasonable in the context of most solid state amplifiers, but can be very misleading when it comes to tube amps. ZD, thanks for the nice words. Best regards, -- Al |
Atmosphere,
A few other "easy load" speaker brands to add to your list.
Rethm, Vaughn Audio, Tonian Labs, Ocellia, Trenner Friedl, Audio Note.
Ralph, there's something that doesn't make sense concerning your comments about speaker designers. These designers have to have at the very least a rudimentary understanding of science and engineering. Something as basic as Kirchoff's law has to be easily comprehended and applied. They have the equipment available to confirm that concept and its effect. I just don't understand why you would be met with such resistance to something so plain and fundamental. How do these designers counter your point/position?
Charles, |
Atmasphere - you have been most helpful. I won't sum up the list of your contributions quite yet though. Am hoping you're not done here ... |
We all know there are plenty of 8 ohm speakers. 16 ohms is a little harder to find. Some examples:
Classic Audio Loudspeakers
Audiokinesis (several models)
High Emotion Audio (Bella Twin- one of the best monitors I've heard)
Quad ESL57 and ESL 63
Lowther, PHY and other full-range drivers
Coincident Technology (not always 16 ohms, but definitely higher impedance)
Rogers LS35A
many vintage horns- Altec, JBL, EV, etc.
ZU Audio has made 32 ohm versions of some of their speakers
Some Pipedreams are set up as higher impedance
Its not important in a 16 ohm load that the impedance curve be ruler flat. In fact that is true of 8-ohm speakers as well. What does seem to be important is that the impedance variation does not fall below about 1/2 the nominal impedance, and when so doing is at a crossover point. ESLs seem to be an exception.
An example of a speaker that is difficult for a tube amplifier is the B&W 802D. This speaker is rated nominally 8 ohms but employs dual woofers, which are both 8 ohms and in parallel, so really this speaker should be rated at 4 ohms since the most power made by the amp will be seeing this load. If you see dual woofers in a loudspeaker, it is really good idea to inquire with the manufacturer about the impedance at the woofer frequency! If it is 4 ohms I would ask if its possible to make a version where the woofers are in series rather than in parallel. If you get a lot of pushback on this topic, move on!
Something that is really important when matching a tube amplifier to a loudspeaker is to understand that it can't double power as impedance is cut in half. Where this gets you in trouble with speaker designers is that many of them use the sensitivity specification when rating their speakers. Sensitivity is 2.83 volts into the speaker and measured at 1 meter. If the speaker is 8 ohms, this is one watt. But if the speaker is 4 ohms, this is 2 watts- IOW the speaker is actually 3 db less **efficient** than it would seem to appear.
Where the trouble spot is: many designers don't really see a difference between sensitivity and efficiency- so they think that by paralleling a driver, the efficiency of the speaker is increased by 3 db! IME when you try to correct them on this issue, often you get an angry response.
Now it happens that if you parallel a pair of woofers or put them in series, they will act exactly the same in the cabinet designed for them, the only difference is the values used in the crossover. I am going to use Kirchoff's Law here to make the point- if you have a single woofer and put one watt into it, it might make 92 db at one meter. If you have two of the same woofers in either parallel or in series and put 1 watt into the array, the result will be the each driver will have 1/2 watt on them- and the output will be exactly the same 92 db. If the efficiency were to actually go up, it would violate Kirchoff's Law, and because that is impossible (just like its impossible to violate Ohm's Law) it doesn't happen.
I can't tell you how hard it can be to get this fact across to speaker designers- its enough of a problem that I consider it an embarrassment (due to lack of engineering knowledge) when I encounter it. When you run into this, its guaranteed that the designer is using a transistor amplifier for design and testing and really does not understand the relationship between the amp and the speaker.
Now if you know all this above, and you know that higher impedances are good for tube amps as they will make less distortion and more power, then you are well ahead of many speaker designers and you now have a better chance of extracting all the performance out of the tube amp that otherwise is left on the table. Its your dollars in that amp- why not use it to best effect?? |
Charles - thanks for another very helpful post! I assume you mean wrt average power output, at your listening level, you're only using fractions of a watt. I suppose it doesn't matter since even if it is much greater at peak maybe we're talking only 2-8W which you can handle within optimal range. I do realize you have a very efficient setup so my math may be off, but the "fractions of a watt" does sound a bit surprising and if it's true then I'm impressed - jealous even. These are the Coincidents that you refer to?
Yes I understand how power relates to impedance. No need to go there.
Do realize that yours is another data point and opinion, albeit a very popular one. Others commenting here have stated that over-driven tube amps might be appealing to some listeners. Actually they said it more strongly than that, but I'm trying to keep this civil. |
From my experience I've seen a lot of tube amp owners who like distortion. Not SET guys with highly sensitive speakers, but the 10-20 Watt tube amp owners who mate their amp with a speaker rated much below 90dB.
A good friend of mine is a recording engineer and he always says "people love distortion"... In the studio throw a tube compressor on - and ''fatten" up the sound - warm things up. It's the same effect when someone uses a 10 Watt tube amp on a pair of speakers that are rated 25 Watts minimum. I see guys do it all the time - they're fully aware of the speaker's specs, and despite the manufacturer's advice to use more power they do it anyway. It's a seductive sound - but the product of distortion. |
Hazyi,
I can't speak for all owners of lower power tube amplifiers other than to say
I doubt they're intentionally seeking a "distorted" sound
experience. Al and Atmasphere's post are worth re reading. My speakers
are 94db at 14 ohms (minium 10 ohm load). My amplifier is an 8 watt SET
my average listening level is roughly 75-80db C weighted I sit 10 feet from
the speakers. Under these conditions I'm using only "fractions"
of 1 watt to achieve this very adequate listening volume. Most of my jazz
CDs have a dynamic range of 25-30db (some have an even wider range).
So there's ample head room in reserve when necessary to account for
musical peaks. The distortion levels are miniscule as I'm using mere
fractions of a single watt. The sound is pure and beautiful and there's no
need for "induced" distortion, In reality, quite the contrary. I
agree with Atmasphere's point regarding the advantages of high speaker
ohm impedance based on my daily listening experiences. Hazyi, I hope this
perspective helps make the point that gratuitous distortion isn't the appeal
for tube amplifiers.
Charles |
By appropriate, I mean a speaker that is efficient enough to provide the volume you need in the room you are using, that has the high-ish, relatively flat impedance curve that tube amps work best with. For the reasons that Almarg and Atmasphere elucidated, that efficiency had better be pretty high (>95 DB or more) if you want to make reasonably high volumes in a moderate to large rooms using an SET amp, but there are a good number of push pulls tube amps, w or wo OPTs that can drive speakers in the 85+dB range if the impedance is flat and >= 6 ohms. |
Zd - thanks for this most helpful reply. I do understand the idea of "less bad" distortion at at or near clipping (I really do!), so it's not a missing piece if there was one. Rather you hit the nail on the head when you wrote "But I think it would be a mistake to say people buy tube amps to make them distort." I would have believed that a month ago before I started reading ... whatever I've been reading (I know - maybe I should stop reading, but then again what are the rest of you doing here? You should be listening to your systems! Sadly mine is missing an amp). And now there's a couple people commenting here that seem to be contradicting your statement. So, are there any closeted tubies here willing to come forward and confess to their tube clipping fetishes? |
As usual, Al's explanations are exceptional and I agree with everything he says in his post. I'm not sure if I'm getting this line in the OP's first post.
"If the rating is too high won't that mean lower distortion and hence less tube sound for a given volume for those speakers than a lower power tube amp (in general that is - I realize not all Watts are the same). So won't a high wattage tube amp have less of the special tube sound "tubies" like at their preferred listening volume?"
When I read that, it sounds to me like people with tube gear are choosing lower power amps so that they will distort. And the distortion is pleasing to the ear. That's not the case. People with tubes, just like people with SS, don't want their amps to distort. But if, and when, distortion does occur, there are those who feel that tubes sound "less bad" when they distort. I think that might be the missing piece you were looking for. But I think it would be a mistake to say people buy tube amps to make them distort. (Unless they play guitar. lol) Also, something else to consider is that tube amps and SS amps sound different from each other when they are not distorting. And both designs are liked and disliked, for the way they sound when operating under normal circumstances. That's why in my first post, I said why don't you listen to some tube gear. Its something you really need to hear for yourself to form an opinion. Its not easy to put this stuff into words. |
Atmasphere, who out there today is making good quality 16 ohm speakers? With no impedance dips much below that I mean.
A google search on 16 ohm speakers turns up little at least on teh fist page.
WHat are some good ones at various price points? Which ones are full range? |
Hazyj, There is something to the idea that smaller amps sound better. In the case of push-pull tube amps, this has almost entirely to do with the output transformer itself. The reason for this is that the more power the output transformer can handle, the less bandwidth it has. So in the larger designs, usually the designer has made a tradeoff based entirely on what he thinks is important.
If the amp employs negative feedback, usually the high frequency bandwidth is the area that is sacrificed. This is because there is not a lot of energy at high frequencies so its possible to get away with this if you also run negative feedback to help output a little with the voltage response of the amp which will be degraded (another way of looking at this is the output impedance will be higher at the area of the rolloff and beyond).
In the old days, 60 watts was about the limit where the output transformer could make the bandwidth required to really be hifi. That bandwidth BTW is well past 20Hz-20KHz; its nice to get response up to 100KHz if you can so phase shift at 10KHz is not adversely affected. This really helps with the presentation of the soundstage, depth in particular.
These days designers seem to have pushed that power level up to about 100 watts before bandwidth really starts to suffer.
Now the problem with push-pull is often that there is a phase-splitter circuit that introduces some distortion. This is not true of all P-P amps, but it is true of most of them. This generally is not an issue until you get into the lower power regions of the amplifier, at which point the distortion of the phase splitter comes into play. For this reason a highly efficient speaker (+98 db or so) may not be the best choice with a plus-100 watt amplifier as you may never get the amp out of that region of higher distortion at lower power levels.
SET amplifiers get around this problem by not having a phase splitter (that's how we do it too although our amps are push-pull). This allows them to have a distortion characteristic that becomes unmeasurable as the power decreases to zero. To really take advantage of this, you really do need a high efficiency loudspeaker! The reason is two-fold with SETs- first, that bandwidth limit discussed with the OPT of P-P amps is more profound with SETs, the practical upper limit being only about 7 watts before bandwidth is degraded (for this reason many SET designers don't bother trying to get the bass right in the OPT as the speakers that have that kind of efficiency don't play the bottom octave either). The second reason is that you never want to push an SET past about 20% of full power or else the higher ordered distortion products come into play (when this happens, its usually on transients, and because the human ear uses the higher orders as loudness cues, the result is that the SET sounds a lot more dynamic than it has any right to because the loudness cues are occurring on the transients. You read about this 'dynamic' character with SETs all the time, but its an indication that the speaker used is not efficient enough).
Where is is all going is that if you want to really get the most out of your tube amplifier investment dollar, the selection of the loudspeaker is really important!
Something else to be aware of: Tube amps make more power and run more efficiently into higher impedances. You really don't want to make **any** amplifier (tube or transistor) work all that hard- the harder you make it work, the more distortion it will have. So you want to avoid 4 ohm speakers generally speaking- the amp will make less distortion into 8 or 16 ohms. This has nothing to do with whether the amp employs negative feedback or not- and it has everything to do with the fact that OPTs operate more effectively (wider bandwidth, lower distortion, less amplifier power converted to heat) into higher impedances. This is why you are seeing more 16 ohm speakers on the market these days- designers are slowly figuring this out. |
Zkzpb8 & Mapman - thanks!
Almarg - very helpful, thanks! Yes, my post is focused narrowly on this one question, but I'm not. When I listen I listen for what pleases my ear. If this is one of the things that does or does not then I'll note that fact and keep listening. I'm not really looking for specific amplifier suggestions, at least it didn't occur to me to do that. If I do it will be in another post, but I doubt that'll be necessary. |
As I understand the question, you are seeking to determine if in general it makes sense to prefer a lower powered tube amp to a higher powered tube amp (assuming that both amps can provide sufficient watts for the application), due to an expectation that the lower powered amp may, under typical conditions, tend to distort more than the higher powered amp. And thereby provide sonic characteristics that are more "tubey" and less solid state-like than would otherwise be the case.
That is a logical question, but I think it focuses MUCH too narrowly on one single factor in tube amp sonics for any answers to be useful. There are simply way too many variables involved in the design and the performance characteristics of an amplifier, and in its interaction with the technical characteristics of whatever speaker is being used, for a useful answer to be defined. Certainly among different makes of amplifiers. And even when considering amps from a given manufacturer having different power ratings, that are otherwise generally similar in design, I see no reason to expect much consistency among the product lines of different manufacturers as to whether the higher powered or lower powered amp would be preferable. Or even much consistency across a variety of speakers when a comparison is performed between a given higher powered and lower powered amp, as a given tube amp can sound quite different depending on the magnitudes and phase angles of the impedances of the speakers it may be used with, and especially on how those parameters vary as a function of frequency.
Also, the question focuses on just one kind of distortion, harmonic distortion. There are other kinds, e.g., intermodulation distortion, transient intermodulation distortion, crossover distortion, etc. Some of these are neither generally specified nor even measurable in a standardized manner. And all involve a complex signal-dependent mix of different effects and different degrees of effects at different frequencies.
What I would suggest as the most useful line of inquiry, when you reach that point, is that you start a thread indicating the particular speakers that would be used, your budget range for amplification, the room size and listening distance, some idea of the volume levels you prefer, and (especially) whether or not your listening includes recordings having particularly wide dynamic range (i.e., particularly large DIFFERENCES between the volumes of the loudest and the softest notes, such as is often the case with well engineered, minimally compressed, classical symphonic music). The latter factor will dramatically affect how much power you need. Providing that information will get you many knowledgeable and useful suggestions from the members here, from which you can develop a “short list” of candidates.
Good luck. Regards,
-- Al
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"Probably... A lot of what people like is the compression and fatness that occurs when an underpowered tube amp is over driven"
That's a very good point and a great example of how the best technical performance in terms of accuracy does not always win. |
Cool to hear that you're checking out different gear - have fun listening. Some lower powered amps can bring some magic- but one limiting factor could be with music that is more dynamic. Sometimes too much compression can set in and instead of enhancing the sound, the amp will act more as a limiter... |
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If you have relatively efficient speakers (89 to 90db or around there) and a relatively powerful amp that's not one of those tiny wattage esoteric gizmos, you can stop worrying and simply enjoy the damn thing. If the amp doesn't hum or explode and is made by a company that isn't insane, and it sounds good, you're only going to be using about 5 watts most of the time. Seriously...I use a classic old school (but new design with better than old amp innards) push pull amp with something like 65 watts per side and, fortunately, all of the watts sound great...who knew? One thing experienced guitar players have learned from tube amps is they all sound somewhat different from each other, and often WAY different based on output tubes, input tubes, yo mama...etc...but reasonably well made hifi tube stuff often defies the techno bullshit schools of design trendiness and simply works. Try one. |
Jmcgrogan2 - you missed the point of the rhetorical question. were you really laughing out loud?
Swampwalker - define "appropriate"
Zkzpb8 - you got the point of the non-rhetorical question. thank you and nice response!
everyone else - i am listening to whatever I can as much as I can every other day or so. there's only so much time though, so your answers might sway me in the direction of more lower powered tube amp listening. |
"...So won't a high wattage tube amp have less of the special tube sound "tubies" like at their preferred listening volume?"
Probably... A lot of what people like is the compression and fatness that occurs when an underpowered tube amp is over driven. You'll have to try some combinations out, with your speakers, music and listening levels... The amount or lack of distortion that's pleasing to your ears, is up to you... |
What jmcgrogan2 said. As long as the pairing of amp and speakers is appropriate the power rating is irrelevant. |
Why don't you just listen to some tube gear? |
09-23-14: Hazyj
Mulveling - thank you!
Great answer. Does every tube enthusiast agree with this? LOL! Of course not! You are new to this. You will never find every enthusiast to agree on anything. Tubes, SS, digital, analog, cables, etc. Mulveling loves high power tube amps, nothing wrong with that. My tube amp is 35 wpc and my speakers are 91 dB, no audible distortion. While I agree that no one wants to push their amp to hard, as distortion will rise quickly as you reach the clipping point. Most amps operate in a range where distortion is not a factor. I know of folks driving less efficient speakers than I have with even less power and loving it. As Nelson Pass once said, if the first watt doesn't sound great, who wants 200 more watts? Listen to the amp/speaker combo, and don't worry so much about numbers. I've heard amps with high power and low distortion specs sound horrible. Listen to the music and let your ears decide. |
" I'm not sure the purest or cleanest sound does it for everyone"
Nop doubt about that. Top notch technical performance and what people like best are not always the same thing.
The difference is the first is objective and performance claims can be substantiated by measurements.
The second is completely subjective.
The domain of tube amps and SS amps are different, with some overlap but significantly different paradigms at work. But performance is performance.
For me, I have found the best sounding tube amps I have heard sound mostly like the best performing SS ones. What they both share is very high performance well matched into the system as a whole yielding similarly good results, though each different in design operating within distinct paradigms. |
Thanks Mapman. Great response, but is it really true that "that's about it"? Maybe it is. I'm not so certain which is why I posted the question, and I think the only way to know is to hear your same opinion echoed by enough other tube enthusiasts to make it convincing.
But I wouldn't say it's about "the purest tube sound" that I or anyone else seeks. It's about what makes tube listeners happiest. I'm not sure the purest or cleanest sound does it for everyone, but am ready to be proven wrong. |
Hazy,
I don't understand why you are tying this question to optimal power levels. I don't think it has anything to do with that.
If it is the purest tube sound that you seek, that's probably the best tube amp design with the fewest tubes, like some very expensive sets. The best tube amp design is the one with the most linear gain, lowest associated distortion levels, and lowest noise floor. The more tubes involved, most likely the harder it will be to achieve the absolute best performance in this regard. Decide how you will determine those things, then after that, factor in how it will perform with given pair of speakers, which does have everything to do with power levels, and I think that's about it. |
Mulveling - thank you!
"You want your amps to be running in their lowest-distortion range, every time (or as close to that as possible given your SPL needs) -- whether tubes or SS. And you can still clearly hear the effects of tube rolling even when amps are perfectly well within their "clean" range."
Great answer. Does every tube enthusiast agree with this? I know I shouldn't believe everything I read, but it sure seems there are a lot of "audiophiles" who believe a great amp is a great amp tube or SS, and unless you're nearing or at clipping you probably won't hear the tube characteristics that drove your tube enthusiasm to begin with.
So ... if you never operate in this range are you happy with your tubiness? |
