A single frequency through a non linear amp generates 2H, 3H.........That is harmonic distortion. Like you said, music contains multiple frequencies. Each frequency creates it's harmonics due to the non linearity of the amplifier. Then the harmonics of these frequencies mix and create IM.
I think we are talking about the same thing.
Valve amps can also be made low enough distortion to be transparent. Then they sound the same. This has been proven. Since you say you are a new audiophile, perhaps accept some of these things, instead of buying into myths.
No fantasy here. The speakers and room are still making their own sound, but amps don't have to. It's a step in the right direction. As for the recording, it is the recording: as 'playback people', our goal is to access the recording. We can like or dislike the production on its own merits, both musically and sonically. But let's not kid ourselves that amps *have to* be heard, nor chosen based on their distortion's 'better sound'.
It is true. Remember, valve amps can also be made low enough distortion to be transparent. So your argument falls over at the starting gate.
As for inconsistencies, as a new audiophile, you will constantly be given inconsistent suggestions. But you seem to be arriving with strong arguments, rather than being neutral and wanting to sort out the inconsistent advice.
You can easily arrive at the answer to your 'amplifier question' by accepting that good modern SS amps are generally quite transparent, when applied appropriately to loads and voltages as per their intended design. You will hear a lot of uninformed banter to the opposite, of course. You don't have to believe it, though. It's religious.
there are more knowledgeable members here willing to help you out if you are not so deeply brainwashed by snake oil artists....
just by reading here i was able to design and build my own OPT's and work on tube circuits....you just have to be open minded and discerning enough to know when you are being fed hogwash....
just by reading here i was able to design and build my own OPT's and work on tube circuits....you just have to be open minded and discerning enough to know when you are being fed hogwash....
OPT does impedance transformation. It reduces open loop voltage gain but you take account of that in the feedback design so it does not imply more distortion due to reduced feedback.Alan0354 said:
Yes, other things being equal. Other things are not equal, as valves have both less gain and less distortion than typical SS devices. You could turn your argument on its head and say that BJTs are so seriously distorting at more than a few mV signal that it is only because they have some much gain and so can have so much feedback applied to them that they can be used for any amplification at all.
You can get the output impedance low enough. DF of 10 or 20 is sufficient. The fact that an SS amp can get DF up to 500 does not mean that 500 is better than 50. Curiously, some people choose to use very low DF (around 1 or 2) but then either have to buy special speakers or put up with bass boom.
Valves can amplify quite happily up to tens of MHz in wideband circuits (e.g. video) and hundreds of MHz in narrow band circuits (e.g. radio). The problems are different from SS, due to the different impedance, not worse than SS. Of course, you can't expect to amplify MHz with the sort of poor layout you find in a guitar amp.
Distortion has to be low enough to be inaudible (apart from those people who prefer some audible distortion). Both valves and SS can provide sufficiently low distortion. Once it is low enough there is no advantage in making it lower. It just happens that the amount of SS feedback needed to make distortion low enough at 20kHz also makes it much lower at 1kHz but that confers little advantage apart from marketing.
The circlotron gets around your point number (1); it provides a completely balanced output stage.
Concerned your point number (2), as has been remarked elsewhere, tube amplifiers do not have to have output transformers. So in fact a circlotron OTL gets around both of your first two points.
Opinions differ on whether it is good to use negative feedback or not. Of course, with traditional tube amplifiers the output transformer makes it difficult to use a lot a global feedback that includes the transformer in the loop. That objection is circumvented in an OTL amplifier. And a good dose of negative feedback means the output impedance of the OTL can be made very low.
A lot of people argue against using feedback, but I have never found the arguments very compelling. Whether or not the home audio amplifier uses feedback, the fact is that all the way along the chain from the microphones in the recording studio to the output from the CD player, absolutely colossal amounts of feedback have been used at many stages. If this really did have a bad effect on the sound, then it is hardly plausible that it could all be "fixed" by using no feedback at the final stage in the living room.
Chris
That was one of the wisest and "on-point" comments I've read for a while. So true. What makes it even more "marvellous" is that this is by no means a new discovery. ...But I'm afraid that another decade forward from now and we're still in pretty much the same state.
The big problem, the way I see it, is that beginner's first source for information largely are discussions, websites and articles that largely revolve around self-perpetuating myths and which derive credibility from several decades old sources that might have been groundbreaking when they appeared but usually have been debunked several times as technology and our understanding of it has evolved and advanced. Unfortunately, most of the time this "progress" gets unforgotten or is "flying way below radar" for beginners who take their first steps in learning things.
On that note, I'm pretty sure someone will soon chime in to this discussion to enforce his views with links to sources like Wikipedia's "tube sound" article, or Russell O. Hamm's (in)famous whitepaper. Along with many others alike. Sigh.
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Don't worry about it, Teemuk.
When Tellegen invented the pentode, professionals all went "Ah ah! Billiant! And we had triode lovers rubbish it then, and they're still at it.
Some time after the pentode ariived, Schade invented the beam power audio tetrode. And what a step forward it was! But until transistors arrived, there were folk who wouldn't accept anything other than a pentode output.
When Haffler & Keroes invented ultra-linear, professionals all went "Genius. Great" But look in Wireless World back then, and see the vitriol poured on UL. In other audio/electronics magazines too.
When LP records came in, professionals and consumers alike loved them - so much better sound than 78's. But go back and look in old magazines. There were 78 loyalists right up to the 1960's.
When CD's arrived, professionals and consumers alike loved them. So much better sound than LP's. But there's always been a few folk who reckoned LPs had better sound, enough that theyt still make LP's! There nothing rational about any of this.
We've had triode tubes, pentodes germanium bipolar transistors, silicon bipolar transistors, and power FETS. Each has its loyal admirers. If somebody invents a new device that outperforms everything before it, you'll see, there will arrive a band of enthusiasts that will defend to the death bipolar transistors, and dream up all sorts of pseudo-theory to support their arguments.
If history had been different, and the bipolar transistor invented first, and tubes later, we would have a great army of bipolar lovers happlily rubbishing those dreadful tubes.
This is not to say that designing and building tube amps isn't fun. It most certainly is! Thats why you're here isn't it?
When Tellegen invented the pentode, professionals all went "Ah ah! Billiant! And we had triode lovers rubbish it then, and they're still at it.
Some time after the pentode ariived, Schade invented the beam power audio tetrode. And what a step forward it was! But until transistors arrived, there were folk who wouldn't accept anything other than a pentode output.
When Haffler & Keroes invented ultra-linear, professionals all went "Genius. Great" But look in Wireless World back then, and see the vitriol poured on UL. In other audio/electronics magazines too.
When LP records came in, professionals and consumers alike loved them - so much better sound than 78's. But go back and look in old magazines. There were 78 loyalists right up to the 1960's.
When CD's arrived, professionals and consumers alike loved them. So much better sound than LP's. But there's always been a few folk who reckoned LPs had better sound, enough that theyt still make LP's! There nothing rational about any of this.
We've had triode tubes, pentodes germanium bipolar transistors, silicon bipolar transistors, and power FETS. Each has its loyal admirers. If somebody invents a new device that outperforms everything before it, you'll see, there will arrive a band of enthusiasts that will defend to the death bipolar transistors, and dream up all sorts of pseudo-theory to support their arguments.
If history had been different, and the bipolar transistor invented first, and tubes later, we would have a great army of bipolar lovers happlily rubbishing those dreadful tubes.
This is not to say that designing and building tube amps isn't fun. It most certainly is! Thats why you're here isn't it?
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That's why it's so confusing to know what to look for. Not only people here talked about distortion. I am reading Bob Cordell's Audio Power Amp book. I read over 100 pages, everything so far is on distortion, pages and pages of how to lower distortion by emitter degeneration on the IPS, current mirrors to increase impedance and increase OLG. Biasing the output transistor to lower crossover distortion.........Nothing but lowering distortion. It does not say in words that low distortion means better sound, but all the examples sure speaks very loud without saying that.
Sorry to stir up this. I am into audiophile in the sense as an end user, Electronics is my passion, but I am not planning to spend my life chasing for and design/build the ultimate amp. I am an EE for a long time and design guitar amps. My plan is to build an amp that is better than my Acurus in the next few months. I think I have the ability to design and build the amp, BUT my problem is building what amp?!!!! This turn out to be harder than building the amp as circuit is driven by priority. What do you design after? I sure hope I don't have to design and build a few amps before getting the answer!!! That's why I ask about this just like I ask about the parafeed before.
Bottom line is I want to build one amp that sounds good for me, not a few amps. So I have to first decide whether it's going to be tube or SS. Particular components of tube amp are very expensive, but is much easier to build. On the other hand, SS amp are a lot cheaper to build by the mechanical design of the heat sink and enclosure is going to be a lot more difficult. I sure hope I don't invest the time and money to build one and wish I have build the other.
Sorry to stir up this. I am into audiophile in the sense as an end user, Electronics is my passion, but I am not planning to spend my life chasing for and design/build the ultimate amp. I am an EE for a long time and design guitar amps. My plan is to build an amp that is better than my Acurus in the next few months. I think I have the ability to design and build the amp, BUT my problem is building what amp?!!!! This turn out to be harder than building the amp as circuit is driven by priority. What do you design after? I sure hope I don't have to design and build a few amps before getting the answer!!! That's why I ask about this just like I ask about the parafeed before.
Bottom line is I want to build one amp that sounds good for me, not a few amps. So I have to first decide whether it's going to be tube or SS. Particular components of tube amp are very expensive, but is much easier to build. On the other hand, SS amp are a lot cheaper to build by the mechanical design of the heat sink and enclosure is going to be a lot more difficult. I sure hope I don't invest the time and money to build one and wish I have build the other.
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Alan, you have what I call "paralysis analysis"... can't make a decision until you have all the facts. But what may be fact for one person is rubbish for another.
And you can't discuss "sound quality" on a message board because what sounds good to one person, may sound bad to another. What one hears as highly detailed, may to another sound tiring. Different strokes for different folks as they say. How do you discuss sound quality? You can't. Even the best poet out there can't discuss sound quality.
As an EE, you know it's easier to compare measurable properties vs. subjective things. Either has one more voltage or less voltage, more current or less current, more distortion or less distortion. It's a fact. It's a measurable fact... It's easier to compare things you can measure. But one can't compare two amps as one sounding better, and another one sounding not so good.
And you can't discuss "sound quality" on a message board because what sounds good to one person, may sound bad to another. What one hears as highly detailed, may to another sound tiring. Different strokes for different folks as they say. How do you discuss sound quality? You can't. Even the best poet out there can't discuss sound quality.
As an EE, you know it's easier to compare measurable properties vs. subjective things. Either has one more voltage or less voltage, more current or less current, more distortion or less distortion. It's a fact. It's a measurable fact... It's easier to compare things you can measure. But one can't compare two amps as one sounding better, and another one sounding not so good.
I'd suggest BUY one instead. Go listen to different amps and buy what pleases your ear.
SS vs Tubz = false dichotomy, Accurate Amplifiers converge to inaudibility
you can listen with controls, frequency response and level matching, Blinding protocol
then, if you're willing to eq, tweak output Z you get:
which leads to:
build amps if you're a electronics hobbyist - not for "quality audio"
you can listen with controls, frequency response and level matching, Blinding protocol
then, if you're willing to eq, tweak output Z you get:
which leads to:
build amps if you're a electronics hobbyist - not for "quality audio"
I like both types of amps. The tube amps will certainly offer more ear-friendly clipping behavior. In general, I find that tube amps sound very good, but lack the precision of the solid state amps. Some people prefer the slightly less precise transient response of a tube amp in exchange for a warmer and pleasant midrange. Tradeoffs, tradeoffs...
In general, tube amps will be heavier, less power efficient, more expensive, have lower bandwidth, higher distortion, and be more sensitive to load variations than a sand amp. Sand amps, on the other hand, won't look as cool and won't glow pretty in the dark.
In the end, it's a matter of personal preference.
~Tom
In general, tube amps will be heavier, less power efficient, more expensive, have lower bandwidth, higher distortion, and be more sensitive to load variations than a sand amp. Sand amps, on the other hand, won't look as cool and won't glow pretty in the dark.
In the end, it's a matter of personal preference.
~Tom
Stereo amps are just like guitar amps for me, I can't just have one. If you are truly addicted to sound and audio gear like the rest of us freaks on this website then you will have no choice but to either buy or build (this is a diy site right?) several amps both SS and tube. A couple years ago I completed a vintage tube amp restoration and love the results, I also built a couple of the classic Mullard 5-20 power amps, along with "slewmonster" SS amp designed by some smart folks on this website. My next project will probably be DHT amps, why? Because I need to have all the big boy toys before I die
I also recommended reading up on that Bob Carver challenge to you because instead of looking at schematics look at the amps as black boxes and just see the input/output properties of the amp, design your amp around those properties that give you the most listening enjoyment.
I also recommended reading up on that Bob Carver challenge to you because instead of looking at schematics look at the amps as black boxes and just see the input/output properties of the amp, design your amp around those properties that give you the most listening enjoyment.
A sand amp will never look this cool...
Just saying...
~Tom
An externally hosted image should be here but it was not working when we last tested it.
Just saying...
~Tom
Transistors have many advantages over tubes. It's easier to turn the question around and ask, when are tubes better than transistors. I'd say, when they clip, and when they produce a more natural harmonic distortion spectrum before clipping. If clipping never occurs, the difference is VERY small (assuming both circuit designs are done well). Some people can hear a difference and others not. When the difference is indeed audible, it could be because of crossover distortion in a push-pull circuit, more than because it was tubes or transistors.
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