KeithL
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Posts: 10,261
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Post by KeithL on Nov 22, 2024 16:18:47 GMT -5
As for pairing McIntosh with JBL... I haven't listened to JBL's in a very long time... But, as I recall, speakers like their L100's were a little bit bright sounding... and a little but "punchy"... They always sounded to me as if they intentionally had a bit of the "classic smile" EQ... And older McIntosh amplifiers tended to "sound a bit laid back"... So it certainly makes sense that they would complement the sound of each other... It also makes sense that a well-designed direct-coupled amp would sound better with Maggies... Because it's probably going to have better damping... especially at lower frequencies... (And the transformer output on most older McIntosh amps is going to be a liability there...) ... This amp failed to impress with my Maggie 1.6s and were even more lackluster with my 3.7is. Then I bought a couple DR1s as a replacement for significantly less than the MC152, They were a game changer in my system and I haven't looked back. Could that MC452 have been a better choice? Perhaps. ... I think like anywhere else there is a synergy between amp and speaker, I've always used the Pitcher / Catcher "battery" analogy. I've sold a lot of Maggies, and sold Mac too, but back then, Maggies always sounded better to me with a direct coupled amp, which seemed to have more control (possibly damping factor). The first Mac I liked with the Maggies was the MC2205, now almost 50 years old. However a great system I remember was JBL components, actively tri-amped with Mac, the synergy was there. I wouldn't mind trying a current Mac amp with my 20.1s, but too much going on right now. |
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Post by Boomzilla on Nov 22, 2024 16:31:39 GMT -5
...From my limited experience at least some McIntosh amplifiers actually do not sound as good as some of their far cheaper competitors... This is a true statement. But the flip side of this particular coin is ALSO true - Some McIntosh products DO sound as good (and in many cases, better than) their competition (even ignoring price). I had a MC-352 (a big hoss with the output transformers) and it sounded absolutely breathtaking with Thiel 1.6 speakers. Was it accidental synergy? I don't know - an audio amigo begged me to sell him it and I did. But I wish I still had it... Boomzilla |
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Post by audiobill on Nov 22, 2024 16:46:00 GMT -5
Autoformers do add weight and cost, but provide some very beneficial attributes.
Cheaper is rarely better, as in most areas of life. Buy quality, buy once.
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Post by PaulBe on Nov 22, 2024 17:17:27 GMT -5
Autoformers do add weight and cost, but provide some very beneficial attributes. Cheaper is rarely better, as in most areas of life. Buy quality, buy once. What beneficial attributes do you think autoformers have? |
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Post by audiobill on Nov 22, 2024 17:34:55 GMT -5
Transistor power output circuits can match, for example,8-ohm loads directly. This eliminates the need for the output transformer for most manufacturers. However, output stages that are designed to operate into an optimum load of 8 ohms can double or quadruple heat dissipation when operating into 4 or 2 ohm loads. At some frequencies, speakers rated at 8 ohms can dip as low as 4 ohms. 4-ohm systems can dip even lower. This mismatch can cause the amplifier to exceed its thermal dissipation limits.
On the other hand, if an amplifier is designed for an optimum load of one or two ohms, a low impedance load would be no problem. However, less power would be available for a speaker having 4 or 8 ohms impedance.
Since early output stages were typically connected in a single ended push-pull circuit, one side of the output was always connected to ground. They were designed to work into an optimum load of say 2.1 ohms. The matching autoformer was connected directly to the output. In such amplifiers, the matching output was for 4, 8 and 16 ohms. Other impedances became available in later amplifiers.
Full continuous amplifier power could be delivered to each of these loads. There is no danger of exceeding safe limits or overheating.
The autoformer also protects speakers from damage in the event of amplifier failure. Should a direct current component appear at the amplifier output, it was shunted by the low DC resistance of the autoformer, instead of passing through the speaker voice coil, which could damage a speaker or even cause a fire. In amplifiers that contain cheap electrolytic capacitors in their power supplies, as many have documented in this forum, this can be a real risk.
Although autoformers add extra cost, weight and take up extra space, they assure a safe, optimum match to a variety of speakers.
Stereophile, in their review of the MC462 amplifier, says:
'The design element that allows McIntosh to do this has been a technical cornerstone of all their solid-state amps: a single-winding transformer called an autotransformer—or, in the trade lingo arguably coined by McIntosh, an Autoformer. Beginning in 1967 with their first transistor amp, the MC2505, McIntosh has used output-stage Autoformers to optimize impedance matching between output devices and loudspeaker loads, as well as to protect the latter from DC. Fifty-two years later, an output-stage Autoformer allows the company to combine the outputs of multiple push-pull amps in a manner that, they say, has unprecedented distortion-cancelling capabilities. (This is also how the MC462 can deliver the same 450Wpc output to its pairs of 2, 4, or 8 ohm speaker taps.)"
And,
"Summing up the McIntosh MC462's measured performance is easy: It is an extraordinarily well-engineered, exceptionally powerful amplifier.—John Atkinson"
And, typically,
"Emotiva's XPA Gen3 amplifier offers high powers with low levels of noise and distortion, at least at frequencies below 10kHz, at a very affordable price. But the amplifier's problems at the top of the audioband bother me. Predicting the subjective effect of this objective behavior is probably an exercise in futility, but I do wonder if it correlates with Herb's finding that the Emotiva sounded "hard and 100% masculine" through two of the speakers he tried with it.—John Atkinson"
I realize that @keithl has strong, understandably biased opinions, but facts are facts on the test bench.
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Post by geebo on Nov 22, 2024 20:13:27 GMT -5
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Post by PaulBe on Nov 22, 2024 20:40:13 GMT -5
Transistor power output circuits can match, for example,8-ohm loads directly. This eliminates the need for the output transformer for most manufacturers. However, output stages that are designed to operate into an optimum load of 8 ohms can double or quadruple heat dissipation when operating into 4 or 2 ohm loads. At some frequencies, speakers rated at 8 ohms can dip as low as 4 ohms. 4-ohm systems can dip even lower. This mismatch can cause the amplifier to exceed its thermal dissipation limits. On the other hand, if an amplifier is designed for an optimum load of one or two ohms, a low impedance load would be no problem. However, less power would be available for a speaker having 4 or 8 ohms impedance. Since early output stages were typically connected in a single ended push-pull circuit, one side of the output was always connected to ground. They were designed to work into an optimum load of say 2.1 ohms. The matching autoformer was connected directly to the output. In such amplifiers, the matching output was for 4, 8 and 16 ohms. Other impedances became available in later amplifiers. Full continuous amplifier power could be delivered to each of these loads. There is no danger of exceeding safe limits or overheating. The autoformer also protects speakers from damage in the event of amplifier failure. Should a direct current component appear at the amplifier output, it was shunted by the low DC resistance of the autoformer, instead of passing through the speaker voice coil, which could damage a speaker or even cause a fire. In amplifiers that contain cheap electrolytic capacitors in their power supplies, as many have documented in this forum, this can be a real risk. Although autoformers add extra cost, weight and take up extra space, they assure a safe, optimum match to a variety of speakers. Stereophile, in their review of the MC462 amplifier, says: 'The design element that allows McIntosh to do this has been a technical cornerstone of all their solid-state amps: a single-winding transformer called an autotransformer—or, in the trade lingo arguably coined by McIntosh, an Autoformer. Beginning in 1967 with their first transistor amp, the MC2505, McIntosh has used output-stage Autoformers to optimize impedance matching between output devices and loudspeaker loads, as well as to protect the latter from DC. Fifty-two years later, an output-stage Autoformer allows the company to combine the outputs of multiple push-pull amps in a manner that, they say, has unprecedented distortion-cancelling capabilities. (This is also how the MC462 can deliver the same 450Wpc output to its pairs of 2, 4, or 8 ohm speaker taps.)" And, "Summing up the McIntosh MC462's measured performance is easy: It is an extraordinarily well-engineered, exceptionally powerful amplifier.—John Atkinson" And, typically, "Emotiva's XPA Gen3 amplifier offers high powers with low levels of noise and distortion, at least at frequencies below 10kHz, at a very affordable price. But the amplifier's problems at the top of the audioband bother me. Predicting the subjective effect of this objective behavior is probably an exercise in futility, but I do wonder if it correlates with Herb's finding that the Emotiva sounded "hard and 100% masculine" through two of the speakers he tried with it.—John Atkinson" I realize that @keithl has strong, understandably biased opinions, but facts are facts on the test bench. You stated the standard McIntosh technobabble. It’s what I expected. I’ve read it for years. It’s the McIntosh mantra. There is no ‘matching’ with a solid state amp that has no output transformer. Either you stay within the SOA of the amp’s output transistors, or you don’t. A solid state amp is a voltage amplifier. An amp with an output transformer has greater problems with varying loads – think normal cone speakers with passive crossovers - because it tries to ‘match’ a fixed load. The only load this kind of amplifier handles well is a resistor. Using different impedance taps is a throwback to Tube amp days when impedance matching was necessary. I want an amp where the power – at least theoretically - doubles when I halve the impedance of the load. An amp with an autoformer will not do that. If I have an amp that puts out 450W into 8 ohms, I want 900W into 4 ohms, and 1800W into 2 ohms. Real amps will not perform that well, but some get close. Remember that most real loads have varying impedance with frequency, dynamics, and voice coil temperature – just the kind of load that an autoformer doesn’t like. Modern solid state amps are almost always DC protected; among other protections. This is standard. This protection costs far less than an autoformer, and has none of the autoformer’s drawbacks like limited frequency response, hysteresis, and soft high frequency response. Perhaps this is why Atkinson finds the Emotiva amp hard and 100% masculine when it’s just that the McIntosh autoformer’d amp sounds soft and feminine – It can’t handle the varying load, with flat frequency response; Fatter and less tight bottom end; Lack of accuracy in details; soft and phase shifted highs – I digress. An autoformer’d amp can be robust, and I’m certain McIntosh amps are capable. But, if McIntosh is truly concerned about electrolytic capacitor failure, perhaps they should buy better capacitors and save money on the autoformers. Facts are facts. Let’s find out how many Emotiva amp owners have had speaker failures because of amp DC problems. I’ll bet you won’t find many. I’m surprised at Atkinson’s comments… " Predicting the subjective effect of this objective behavior is probably an exercise in futility, but I do wonder if it correlates with Herb's finding that the Emotiva sounded "hard and 100% masculine" through two of the speakers he tried with it.—John Atkinson" There's some 'facts on the test bench'. /s |
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Post by Boomzilla on Nov 22, 2024 20:50:16 GMT -5
Emotiva's amplifiers measure most excellently (as Big Dan points out). But we're now on the third generation of Emotiva power amplifiers. I've owned all three generations, and used them with a very wide variety of front ends and speakers. I've stated my opinions before, but to summarize, I liked the sound of the generation one and two amps over the sound of the threes. But obviously, Emotiva had reasons for coming out with new generations of what was already a very successful line of products. Since all three generations measured essentially the same, then WHY did Emotiva bother messing with a good thing? Several possible reasons come to mind: Reliability could be improved with the newer designs, reducing warranty costs? Weight could be reduced with the newer designs, reducing shipping costs? New technology became available that could be incorporated for minimum cost. Now since the amplifiers all measure about the same through all three generations, they should, in theory sound essentially identical. And for the average Emotiva customer, I suspect that they do. But... I'm a special case for the following reasons: 1. I prefer high-sensitivity speakers. 2. I listen at volumes so low that most would complain about them. 3. Because of these reasons, I am never listening at even one watt of amplifier output. So the "first watt" of an amplifier's sound is far, Far, FAR more important to me than to most. Now the Emotiva X-series amps are all running in Class-A mode at such low outputs, meaning that there's virtually NO stress on the amps. They should sound their absolute best since they're essentially "loafing" at my power demands. But for whatever reason, I've consistently found that I prefer the BasX series of Emotiva amps to the X-series. Why? It's a mystery to me. I can easily understand why most potential Emotiva customers would prefer the X-series amps, so don't take my choices as criticism. Further, be assured that your ears probably aren't the same as mine... I won't argue with Dan (saying Emotiva amps are great) or with audiobill (saying that McIntosh amps are great). In fact, I agree with them both. But you aren't buying for Dan or for Bill (or for me) - YOU should listen for yourselves and decide what sounds best with your system, and to your ears. Life's too short to live with suckey power amps! Boomzilla |
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Post by PaulBe on Nov 22, 2024 21:06:03 GMT -5
Emotiva's amplifiers measure most excellently (as Big Dan points out). But we're now on the third generation of Emotiva power amplifiers. I've owned all three generations, and used them with a very wide variety of front ends and speakers. I've stated my opinions before, but to summarize, I liked the sound of the generation one and two amps over the sound of the threes. But obviously, Emotiva had reasons for coming out with new generations of what was already a very successful line of products. Since all three generations measured essentially the same, then WHY did Emotiva bother messing with a good thing? Several possible reasons come to mind: Reliability could be improved with the newer designs, reducing warranty costs? Weight could be reduced with the newer designs, reducing shipping costs? New technology became available that could be incorporated for minimum cost. Now since the amplifiers all measure about the same through all three generations, they should, in theory sound essentially identical. And for the average Emotiva customer, I suspect that they do. But... I'm a special case for the following reasons: 1. I prefer high-sensitivity speakers. 2. I listen at volumes so low that most would complain about them. 3. Because of these reasons, I am never listening at even one watt of amplifier output. So the "first watt" of an amplifier's sound is far, Far, FAR more important to me than to most. Now the Emotiva X-series amps are all running in Class-A mode at such low outputs, meaning that there's virtually NO stress on the amps. They should sound their absolute best since they're essentially "loafing" at my power demands. But for whatever reason, I've consistently found that I prefer the BasX series of Emotiva amps to the X-series. Why? It's a mystery to me. I can easily understand why most potential Emotiva customers would prefer the X-series amps, so don't take my choices as criticism. Further, be assured that your ears probably aren't the same as mine... I won't argue with Dan (saying Emotiva amps are great) or with audiobill (saying that McIntosh amps are great). In fact, I agree with them both. But you aren't buying for Dan or for Bill (or for me) - YOU should listen for yourselves and decide what sounds best with your system, and to your ears. Life's too short to live with suckey power amps! Boomzilla What are the beneficial attributes of McIntosh autoformers? Will the Bose purchase have any impact on McIntosh's use of autoformers? |
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Post by Boomzilla on Nov 22, 2024 22:34:08 GMT -5
What are the beneficial attributes of McIntosh autoformers? Will the Bose purchase have any impact on McIntosh's use of autoformers? For answers to the first part of your question, see audiobill's post above. As to the second part, clairvoyance costs extra! |
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Post by PaulBe on Nov 22, 2024 23:01:58 GMT -5
What are the beneficial attributes of McIntosh autoformers? Will the Bose purchase have any impact on McIntosh's use of autoformers? For answers to the first part of your question, see audiobill 's post above. As to the second part, clairvoyance costs extra! I saw his answer, which was the standard McIntosh technobabble. It’s the McIntosh mantra. From your response, I assume you believe it too. As to the second part, clairvoyance does cost extra. I like my McIntosh MP100 phono preamp, but it will be the only McIntosh purchase for me. |
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Post by mauriceminor on Nov 22, 2024 23:16:05 GMT -5
When the McIntosh Autoformer dissertation concludes perhaps an in-depth discussion on the Porsche IMS bearing is next . . .
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Post by AudioHTIT on Nov 22, 2024 23:17:27 GMT -5
… Will the Bose purchase have any impact on McIntosh's use of autoformers?I’m not sure if this is a rhetorical question, but If it turned out to be true, then all the hand wringing that some have expressed about the Bose acquisition would be justified.. |
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Post by Boomzilla on Nov 23, 2024 1:20:49 GMT -5
Hi PaulBe - I don’t believe anybody’s technobabble. I don’t know enough about audio engineering to evaluate the veracity of them. But I do know what I hear. The two McIntosh components I’ve spent significant time with (a C-41 preamp and a MC-302 power amp) were outstanding sounding units. I wish I had them back! Does this mean that McIntosh’s marketing claims are true? Of course not! But it doesn’t make their claims automatically false either. I just don’t care about their marketing - I ONLY care about their sound. And don’t think that audiobill is gullible either - he knows more about audio design than any half dozen of my other audio amigos. |
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Post by audiobill on Nov 23, 2024 6:22:32 GMT -5
Thanks, Boom - I really don't understand all the anger against the engineering choices of an audio brand who's been very successful since 1949. If it's "technobabble" someone wants, there are many far better examples out there. Peace, all, and enjoy your music. ps: my wife insists on blue meters....  |
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Post by PaulBe on Nov 23, 2024 8:03:15 GMT -5
… Will the Bose purchase have any impact on McIntosh's use of autoformers?I’m not sure if this is a rhetorical question, but If it turned out to be true, then all the hand wringing that some have expressed about the Bose acquisition would be justified.. That is one way of looking at it. The other way is that the autoformer issue would be gratefully dead... Then we could move on to 'W hy did McIntosh have to promote their use, long after they were of any use...?'. THIS isn't a rhetorical question. My apologies - "...never free a mind once it's reached a certain age. It's dangerous, the mind has trouble letting go. I've seen it before and I'm sorry." |
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Post by PaulBe on Nov 23, 2024 8:33:09 GMT -5
Hi PaulBe - I don’t believe anybody’s technobabble. I don’t know enough about audio engineering to evaluate the veracity of them. But I do know what I hear. The two McIntosh components I’ve spent significant time with (a C-41 preamp and a MC-302 power amp) were outstanding sounding units. I wish I had them back! Does this mean that McIntosh’s marketing claims are true? Of course not! But it doesn’t make their claims automatically false either. I just don’t care about their marketing - I ONLY care about their sound. And don’t think that audiobill is gullible either - he knows more about audio design than any half dozen of my other audio amigos. Okie-Dokie. How about those single ended push-pull amps that audiobill mentioned? Any experience with them? Did your C-41 have an autoformer at the output? “This above all: to thine own self be true, And it must follow, as the night the day, Thou canst not then be false to any man.” Hamlet - Polonius, Act 1, Scene 3 |
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Post by audiobill on Nov 23, 2024 8:47:37 GMT -5
Paul, why not just enjoy your RMC-1L and drop this?
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Post by PaulBe on Nov 23, 2024 8:56:25 GMT -5
Paul, why not just enjoy your RMC-1L and drop this? "Bose Buys McIntosh and Sonus Faber". This thread is about Bose, McIntosh, and Sonus Faber. Right? Why does an honest discussion upset you so much? I don't care if you buy McIntosh gear. I own a piece too. It's just stereo equipment. |
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Post by thompson12 on Nov 23, 2024 9:00:13 GMT -5
Thanks, Boom - I really don't understand all the anger against the engineering choices of an audio brand who's been very successful since 1949. If it's "technobabble" someone wants, there are many far better examples out there. Peace, all, and enjoy your music. ps: my wife insists on blue meters.... View AttachmentNice Bill, Tell your wife good taste. I always loved the blue meters as well. Mitch |
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... This amp failed to impress with my Maggie 1.6s and were even more lackluster with my 3.7is. Then I bought a couple DR1s as a replacement for significantly less than the MC152, They were a game changer in my system and I haven't looked back. Could that MC452 have been a better choice? Perhaps. ...I think like anywhere else there is a synergy between amp and speaker, I've always used the Pitcher / Catcher "battery" analogy. I've sold a lot of Maggies, and sold Mac too, but back then, Maggies always sounded better to me with a direct coupled amp, which seemed to have more control (possibly damping factor). The first Mac I liked with the Maggies was the MC2205, now almost 50 years old. However a great system I remember was JBL components, actively tri-amped with Mac, the synergy was there. I wouldn't mind trying a current Mac amp with my 20.1s, but too much going on right now.
