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The Bill May Report on Single-Ended Output Transformers for 300B etc
THE BILL MAY REPORT
Buying the best output transformer Should you choose on measurements, reputation or price?=20 Bill May explains how professionals evaluate transformers. Your average audiophile is lucky if he gets to hear two or three output transformers before he makes his choice. It probably takes him a lot of time and organization to hear that many. So how does he make his choice? There are only three ways: listening to enough transformers under controlled conditions to make a choice, buying on measurements, and buying on recommendation. Listening to one or two or three isn't really enough. For the test to be meaningful, the transformers must be installed in duplicate amps, or at least in very similar amps. For the choice to be meaningful, the transformers must be installed in an amp very similar to what the user will build. He can study manufacturer's spec sheets. Some manufacturers lie, or take their measurements in such a way that they are not truly relevant to any real-life amplifier. That's before the hype even starts. Those who read the hype can easily be misled into thinking there is a single figure of merit for a transformer. It can be bandwidth, low bass extension, power handling. It isn't true. Any transformer that will sound good has all its desirable technical features in balance. The hype includes the price and the reputation of the transformer. That makes sighted tests suspect to any engineer. He can ask for recommendations. The problem is that those who recommend a particular transformer may have heard only that transformer, or perhaps one other, and possibly not in suitable amplifiers. Or the recommendation may be informed by nothing more than spec sheets and hype. In the end, only relevant, blind listening tests count. This doesn't apply only to the average audiophile. Even professionals can be taken in! Here is an example of how measurements, hype and blind tests can produce different results These tests were conducted to choose the output transformers to be used in an amplifier Real McCoy Audio was designing for Japanese manufacture. The manufacturer intended us to choose between the six most expensive Japanese transformers. The cheapest Tango, the Swedish Lundahl, American Magnequests and British Audio Note UK transformers were added as statistical controls, and the no-name potted Chinese and open-frame Russian ones as placebos. The electrical ratings are for weighted results of measurements taken in circuits optimized to the transformers. In the sighted tests knowledgeable listeners were permitted to see the transformers and were told their relative prices, if they asked. I have included a price scale, on which 1 is expensive and 5 is cheap. In the blind tests no-one in contact with the listening panel knew which transformer was being evaluated. The sighted tests were conducted after the blind tests. Several of the tests were repeated with a different listening group to confirm the result. TEST RATINGS OF 13 OUTPUT TRANSFORMERS Rating Measurements Sighted Blind 1 Tango 1 Tango 1 Lundahl 3 2 Lundahl 3 Tango 2 Nature Sound 1 3 Tamura 1 Tamura 1 Tango 2 4 Nature Sound 1 Nature Sound 1 Tamura 1 5 Nature Sound 2 Magnequest 1 Tango 1 6 Tamura 2 Nature Sound 2 Nature Sound 2 7 Tango 2 Lundahl 3 Audio Note UK 4 8 Magnequest 1 Tamura 2 Tamura 2 9 Audio Note UK 4 Audio Note UK4 Russian 4 10 Magnequest 2 Magnequest 2 Magnequest 1 11 Tango 3 Tango 3 Tango 3 12 Chinese 5 Russian 4 Chinese 5 13 Russian 4 Chinese 5 Magnequest 2 (If the table doesn't look right, select the table text, select Courier font, reduce font size until it makes four clean columns) The Measurements column holds no surprises. On measurement, all of these except the Russian transformer are good performers. Some audiophiles scoff at the idea that a set of electrical measurements may predict the outcome of taste tests with certainty. That is true. But if one lowers the expectation a little, correctly weighted measurements will at least eliminate components on which further time should not be wasted. That proved the case here. Of the bottom five in the measurements rating, only one transformer is not in the bottom five in the blind listening tests. The Blind Listening Tests in the last column hold several surprises. A comparison with the Measurements table shows that the best-measuring transformer does not always sound the best. Price comparisons show that the most expensive transformer does not always sound the best, even within the same brand. The high rating of the Russian transformer shows that precision is not as highly valued among the musically inclined as engineers would prefer. The Russian transformer rose so far above its measurements in the listening tests because its inaccuracies are aurally pleasing in the "presence range". One of the listening panel noted in his Comments block: "Who cares about accuracy when you can have ecstacy." The Sighted Listening column shows the effect of brand name, hype, and possibly of appearance. Comparison with the Blind Listening column shows that some reputations are earned and some are not. The same comparison shows that an industrial physical appearance can depress the sighted rating of a transformer like the Lundahl which measures exceptionally well and in the blind listening tests came first.=20 Equally hype can boost the sighted rating of a transformer, like both the Magnequests, well beyond its rating in either measurements or on blind listening. A comparison between blind and sighted ratings of the Japanese transformers is interesting. It shows that even where appearance is not a consideration, and the reputation is earned, knowledge of relative price can distort the rating. The chief conclusions to emerge from these tests are that with regard to output selection transformers for listening pleasure and fidelity: =B7 data sheet measurements and reputation must be supplemented by other means to predict listening pleasure =B7 careful weighting of measurements on hand of experience goes some way towards an initial rough selection =B7 sighted listening tests are too subject to the effects of reputation and hype to be used as a predictor of listening pleasure =B7 blind listening tests prove that some reputations are earned =B7 blind listening tests prove that a high reputation achieved by hype is no guarantee of listening pleasure =B7 blind listening tests prove that high price is no guarantee of listening pleasure =B7 blind listening tests prove that an industrial appearance, if kept out of sight, is no bar to listening pleasure =B7 blind listening tests prove that a modest price is no bar to listening pleasure =B7 success in blind listening tests is not always a guarantee of fidelity in reproduction =B7 blind listening tests should therefore always be used =B7 but only in conjunction with careful interpretation of the measurements Incidentally, after examining our results the Japanese manufacturer chose the mid-price Tango for sonic, marketing and financial reasons. Bill May spent forty years in high tension electricity supply. A long-time tube hi-fi enthusiast, he is now technical director of Real McCoy Audio, a design and prototyping shop. =A9 Copyright 1998 William May and Real McCoy Audio. May be reprinted freely on the internet only if reproduced in full including this copyright and permission notice. =20 |
#2
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Fran=E7ois Yves Le Gal wrote On 2 May 2005 15:48:43 -0700,
" wrote: THE BILL MAY REPORT William "Bill" May doesn't exist : he is another one of your sockppupets, Jute. You created it during your ill fated crusade against Magnequest in 1988. BTW, Real McCoy amplifiers don't exist, your KISS amp doesn't exist. You're a sick ****, Jute. If you want to believe the lies Creepy Mike LaFever of Magnequest tells you, Toad, I'm sure they'll make you feel better. In fact, if it will make you feel better, I will confess to not existing either. I am an artifact of my art teacher's mind with additional dialogue by my favourite English teacher. Meanwhile, here is Bill May's report again. It carries the date of first publication in the copyright notice at the bottom. -- Andre Jute THE BILL MAY REPORT Buying the best output transformer Should you choose on measurements, reputation or price? Bill May explains how professionals evaluate transformers. Your average audiophile is lucky if he gets to hear two or three output transformers before he makes his choice. It probably takes him a lot of time and organization to hear that many. So how does he make his choice? There are only three ways: listening to enough transformers under controlled conditions to make a choice, buying on measurements, and buying on recommendation. Listening to one or two or three isn't really enough. For the test to be meaningful, the transformers must be installed in duplicate amps, or at least in very similar amps. For the choice to be meaningful, the transformers must be installed in an amp very similar to what the user will build. He can study manufacturer's spec sheets. Some manufacturers lie, or take their measurements in such a way that they are not truly relevant to any real-life amplifier. That's before the hype even starts. Those who read the hype can easily be misled into thinking there is a single figure of merit for a transformer. It can be bandwidth, low bass extension, power handling. It isn't true. Any transformer that will sound good has all its desirable technical features in balance. The hype includes the price and the reputation of the transformer. That makes sighted tests suspect to any engineer. He can ask for recommendations. The problem is that those who recommend a particular transformer may have heard only that transformer, or perhaps one other, and possibly not in suitable amplifiers. Or the recommendation may be informed by nothing more than spec sheets and hype. In the end, only relevant, blind listening tests count. This doesn't apply only to the average audiophile. Even professionals can be taken in! Here is an example of how measurements, hype and blind tests can produce different results These tests were conducted to choose the output transformers to be used in an amplifier Real McCoy Audio was designing for Japanese manufacture. The manufacturer intended us to choose between the six most expensive Japanese transformers. The cheapest Tango, the Swedish Lundahl, American Magnequests and British Audio Note UK transformers were added as statistical controls, and the no-name potted Chinese and open-frame Russian ones as placebos. The electrical ratings are for weighted results of measurements taken in circuits optimized to the transformers. In the sighted tests knowledgeable listeners were permitted to see the transformers and were told their relative prices, if they asked. I have included a price scale, on which 1 is expensive and 5 is cheap. In the blind tests no-one in contact with the listening panel knew which transformer was being evaluated. The sighted tests were conducted after the blind tests. Several of the tests were repeated with a different listening group to confirm the result. TEST RATINGS OF 13 OUTPUT TRANSFORMERS Rating Measurements Sighted Blind 1 Tango 1 Tango 1 Lundahl 3 2 Lundahl 3 Tango 2 Nature Sound 1 3 Tamura 1 Tamura 1 Tango 2 4 Nature Sound 1 Nature Sound 1 Tamura 1 5 Nature Sound 2 Magnequest 1 Tango 1 6 Tamura 2 Nature Sound 2 Nature Sound 2 7 Tango 2 Lundahl 3 Audio Note UK 4 8 Magnequest 1 Tamura 2 Tamura 2 9 Audio Note UK 4 Audio Note UK4 Russian 4 10 Magnequest 2 Magnequest 2 Magnequest 1 11 Tango 3 Tango 3 Tango 3 12 Chinese 5 Russian 4 Chinese 5 13 Russian 4 Chinese 5 Magnequest 2 (If the table doesn't look right, select the table text, select Courier font, reduce font size until it makes four clean columns) The Measurements column holds no surprises. On measurement, all of these except the Russian transformer are good performers. Some audiophiles scoff at the idea that a set of electrical measurements may predict the outcome of taste tests with certainty. That is true. But if one lowers the expectation a little, correctly weighted measurements will at least eliminate components on which further time should not be wasted. That proved the case here. Of the bottom five in the measurements rating, only one transformer is not in the bottom five in the blind listening tests. The Blind Listening Tests in the last column hold several surprises. A comparison with the Measurements table shows that the best-measuring transformer does not always sound the best. Price comparisons show that the most expensive transformer does not always sound the best, even within the same brand. The high rating of the Russian transformer shows that precision is not as highly valued among the musically inclined as engineers would prefer. The Russian transformer rose so far above its measurements in the listening tests because its inaccuracies are aurally pleasing in the "presence range". One of the listening panel noted in his Comments block: "Who cares about accuracy when you can have ecstacy." The Sighted Listening column shows the effect of brand name, hype, and possibly of appearance. Comparison with the Blind Listening column shows that some reputations are earned and some are not. The same comparison shows that an industrial physical appearance can depress the sighted rating of a transformer like the Lundahl which measures exceptionally well and in the blind listening tests came first. Equally hype can boost the sighted rating of a transformer, like both the Magnequests, well beyond its rating in either measurements or on blind listening. A comparison between blind and sighted ratings of the Japanese transformers is interesting. It shows that even where appearance is not a consideration, and the reputation is earned, knowledge of relative price can distort the rating. The chief conclusions to emerge from these tests are that with regard to output selection transformers for listening pleasure and fidelity: =B7 data sheet measurements and reputation must be supplemented by other means to predict listening pleasure =B7 careful weighting of measurements on hand of experience goes some way towards an initial rough selection =B7 sighted listening tests are too subject to the effects of reputation and hype to be used as a predictor of listening pleasure =B7 blind listening tests prove that some reputations are earned =B7 blind listening tests prove that a high reputation achieved by hype is no guarantee of listening pleasure =B7 blind listening tests prove that high price is no guarantee of listening pleasure =B7 blind listening tests prove that an industrial appearance, if kept out of sight, is no bar to listening pleasure =B7 blind listening tests prove that a modest price is no bar to listening pleasure =B7 success in blind listening tests is not always a guarantee of fidelity in reproduction =B7 blind listening tests should therefore always be used =B7 but only in conjunction with careful interpretation of the measurements Incidentally, after examining our results the Japanese manufacturer chose the mid-price Tango for sonic, marketing and financial reasons. Bill May spent forty years in high tension electricity supply. A long-time tube hi-fi enthusiast, he is now technical director of Real McCoy Audio, a design and prototyping shop. =A9 Copyright 1998 William May and Real McCoy Audio. May be reprinted freely on the internet only if reproduced in full including this copyright and permission notice. |
#4
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On 2 May 2005 18:07:10 -0700, "
wrote: François Yves Le Gal wrote On 2 May 2005 15:48:43 -0700, " wrote: THE BILL MAY REPORT William "Bill" May doesn't exist : he is another one of your sockppupets, Jute. You created it during your ill fated crusade against Magnequest in 1988. BTW, Real McCoy amplifiers don't exist, your KISS amp doesn't exist. You're a sick ****, Jute. If you want to believe the lies Creepy Mike LaFever of Magnequest tells you, Toad, I'm sure they'll make you feel better. In fact, if it will make you feel better, I will confess to not existing either. I am an artifact of my art teacher's mind with additional dialogue by my favourite English teacher. Meanwhile, here is Bill May's report again. It carries the date of first publication in the copyright notice at the bottom. -- Andre Jute snip more Jute sockpuppet bull**** Lest we forget, the Magnaquest fiasco took place in 1998, so of course that 'report' would have the same date. It is of course just another one of Jute's many fictional creations. Don't believe it? Look up Jute on any literary website. He writes *fiction* under the name 'Andrew McCoy'. If that's not enough for you, Jute is not his surname. His *real* name is Andre Jute McCoy, a Sarth Efrikaan of extremely dubious history, and we're all well aware of his despicable (lack of) character. -- Stewart Pinkerton | Music is Art - Audio is Engineering |
#5
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On Tue, 03 May 2005 01:28:58 -0500, DougC
wrote: wrote: If you want to believe the lies Creepy Mike LaFever of Magnequest tells you, Toad, I'm sure they'll make you feel better. In fact, if it will make you feel better, I will confess to not existing either. I am an artifact of my art teacher's mind with additional dialogue by my favourite English teacher. Meanwhile, here is Bill May's report again. It carries the date of first publication in the copyright notice at the bottom. -- Andre Jute (-I am loathe to get involved, but I just gotta say-) ----I don't know who Mike LaFever is, Mike LeFevre of Magnaquest. It's just another one of Jute's childish namecallings. but I do know how to use Google. There is only one return on the search result "bill may real mccoy amplifiers", at http://www.diyparadiso.com/lundahl/shoot1.htm . There are no other hits of any significance for " 'bill may' amplifiers", none for " 'william may' amplifiers", none for "real mccoy amplifiers", or for any combination of the independent terms "bill william may real mccoy amplifiers", or even the name "real mccoy" in connection with any sort of audio business. Since you can find search results on just about any other company that ever existed, I'd agree this is a spoof. The GoogleMatrix p0\/\/\nZ you! Knowing that Jute's full name is Andre Jute McCoy might perhaps offer a clue..................... Also, he writes potboiler thrillers under the name 'Andrew McCoy', so it's reasonable to conclude that the 'Bill May Report' is also fictional. -- Stewart Pinkerton | Music is Art - Audio is Engineering |
#6
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TEST RATINGS OF 13 OUTPUT TRANSFORMERS Rating Measurements Sighted Blind 1 Tango 1 Tango 1 Lundahl 3 2 Lundahl 3 Tango 2 Nature Sound 1 3 Tamura 1 Tamura 1 Tango 2 4 Nature Sound 1 Nature Sound 1 Tamura 1 5 Nature Sound 2 Magnequest 1 Tango 1 6 Tamura 2 Nature Sound 2 Nature Sound 2 7 Tango 2 Lundahl 3 Audio Note UK 4 8 Magnequest 1 Tamura 2 Tamura 2 9 Audio Note UK 4 Audio Note UK4 Russian 4 10 Magnequest 2 Magnequest 2 Magnequest 1 11 Tango 3 Tango 3 Tango 3 12 Chinese 5 Russian 4 Chinese 5 13 Russian 4 Chinese 5 Magnequest 2 Incidentally, after examining our results the Japanese manufacturer chose the mid-price Tango for sonic, marketing and financial reasons. I would have went with the "Lundahl 3" as the blind tests say it's the best one and is mid priced. I'm not sure what "industrial" appearance looks like, but I prefer my tube amp tubes and the rest to be inside of metal boxes so physical appearance beyond safety and build quality is of little concern. |
#7
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robert casey wrote:
TEST RATINGS OF 13 OUTPUT TRANSFORMERS Rating Measurements Sighted Blind 1 Tango 1 Tango 1 Lundahl 3 2 Lundahl 3 Tango 2 Nature Sound 1 3 Tamura 1 Tamura 1 Tango 2 4 Nature Sound 1 Nature Sound 1 Tamura 1 5 Nature Sound 2 Magnequest 1 Tango 1 6 Tamura 2 Nature Sound 2 Nature Sound 2 7 Tango 2 Lundahl 3 Audio Note UK 4 8 Magnequest 1 Tamura 2 Tamura 2 9 Audio Note UK 4 Audio Note UK4 Russian 4 10 Magnequest 2 Magnequest 2 Magnequest 1 11 Tango 3 Tango 3 Tango 3 12 Chinese 5 Russian 4 Chinese 5 13 Russian 4 Chinese 5 Magnequest 2 Incidentally, after examining our results the Japanese manufacturer chose the mid-price Tango for sonic, marketing and financial reasons. I would have went with the "Lundahl 3" as the blind tests say it's the best one and is mid priced. I'm not sure what "industrial" appearance looks like, but I prefer my tube amp tubes and the rest to be inside of metal boxes so physical appearance beyond safety and build quality is of little concern. You got it, Robert. But niche market tube amp design is not necessarily directed entirely by electronic rationality. This Japanese manufacturer's first idea was an amp around Magnequest transformers because they were rare and "made in America". After Bill's tests he changed his mind. I wanted the Lundahl as the obvious logical choice but this Japanese amp maker didn't want a) Swedish transformers and b) transformers under the deck. His wife, who does his accounts, told me the midprice Tangos were chosen because they wanted "the money visible on the deck" but they feared the top Tango would make the price so high nobody would buy the amp. Many years later they are still in business, so they must know their business. Andre Jute |
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