george hifi,
Maybe you do much less listening than analyzing specs. The Levinson ML2 fully broken in which I owned years ago was syrupy euphonic and veiled at low/moderate volumes with my electrostatic speakers. Instead of claiming ricevs is a promoter for his amp, why don't you spend a little money, find out whether the phase shift has any relevance in your listening. No risk to you, and then you could have more credible comments. Alternatively, have someone gather a bunch of amps whose specs are unknown to you, do comparative listening, and see for yourself whether listening tests correlate with the specs. The truth is that there is a very small correlation, but not enough to differentiate among good or great amps. I have heard class D amps that sound euphonic/rolled off in HF, and others that sound harsh. |
I will add that my class D Mytek Brooklyn amp is very neutral, revealing and smooth in the HF. It briefly shuts down at 300 watts into my inefficient electrostatic + parallel Enigmacoustics tweeter combination whose impedance is about 2 ohms in HF. SO WHAT--it plays music beautifully over 99% of the time. I am not complaining about its technical deficiencies. I am looking forward to ricevs' more powerful amp.
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There is indeed no hope for you. All your pseudoscience data is nothing more than pseudoscience because without listening correlation it is irrelevant to the pursuit of audio excellence. Accuracy in sound doesn't necessarily correlate with specs. It is obvious that you don't do any serious listening to confirm what you claim. To prove me wrong, present to this community your listening experiences that corroborate what your measurements say. Without your honest descriptions of your listening, your comments can be ignored. And your simplistic explanations of rolled off or extended HF based on setting of the switching freq output filter are ignorant until you personally measure a product and correlate with the listening.
My credentials are many decades of having played solo violin in major concertos with orchestra, chamber music playing, and listening up close and further away in the hall. I have played examples of most of the great violin masterpieces of the 17th through 19th Century. It doesn't appear that your musical credentials are in my league.
I am also an integrative medicine physician who knows that clinical observation must be correlated with objective lab, electro- and neurologic physiologic and radiological data. Just as it takes decades of clinical experience to know how to combine clinical and objective data in a useful perspective, it also takes informed listening and musical experience and competence to know how to integrate subjective and objective audio data. Even the leading electronics designers are still learning. They change parts and do their tweaks based on listening.
If you claim to know more than anybody, design your own amp, send it to me, and I will tell everyone the truth about it. If it really is great sounding, I am in the market for SOTA and would happily pay you for it as well as proclaim that you really know what you are talking about. I will wait patiently.
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George,
I read what anybody has to say, but the only thing I trust is my own EARS. Do you believe the Electronic Institute rather than your ears? If so, then you believe your ears don't matter and therefore you have lost credibility. I bet that few or none of the Electronic Institute writers have commented about the audibility of any of their claims either. Many audiophiles like me are interested in accuracy of sound from listening, not in writing a postdoc thesis about circuitry/devices/etc. Bruno seems to have expertise in technical theory, but also does the listening. That doesn't mean that I totally agree with what he likes or thinks is accurate sound, but I respect him or anyone else who do both theory and listening. |
Thanks for posting the info about the ME amps. They may sound excellent, but that is not the central issue discussed here. The issue is that you have not shown you understand the correlation of technical measurements with tonal qualities. Worse is that you keep dodging this issue as if you don't care about it. I'm not saying that I do understand the correlations, and most good designers admit that they don't fully understand either. That's why they design according to their technical concepts, but change and tweak based on listening. Bruno Putzeys has written that he works this way. I assume you respect Bruno, so why don't you follow his lead? |
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George,
So what that "a good BJT amp will always drive into these sub 2ohm low impedance’s and do the wattage doubling act better than a Mosfet Class-D even GaN based one
The best linear amps that can do it are all BJ" blah blah. The musical resolution at a fraction of 1 watt could be mediocre. But you don't know this because you don't listen or you don't know what to listen for. Don't attempt to refute me unless you can prove that your musical credentials are on par with mine.
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golfnutz,
Thanks for quoting Stereophile on my Mytek Brooklyn amp. George would say it is a mediocre amp because it doesn't increase its output capability much as the impedance is lowered. SO WHAT? It is a budget amp which happens to have accurate/neutral sound within its power limitations. It sounds much more accurate/neutral than the pure class A Levinson ML2 which was a perfect voltage source with hefty power supply. We are here to find amps that reveal more music, not to debate specs. The latter is for academic societies. Specs are useful to rule out very low powered amps for very inefficient speakers, for example. |
golfnutz,
In my post, I was not defensive about my Mytek Brooklyn amp. I thanked you for quoting Stereophile measurements whose power capabilities are at odds with the excellent sound quality described in the review and confirmed by my listening. My "SO WHAT" comment was intended to refute George who holds up the Levinson ML2 as the paragon of excellence for technical specs. The truth is that it sounds like muddy molasses at any SPL despite its power specs. But George has never heard it, doesn't care to listen, and merely goes on and on about irrelevant technical subjects.
As to your point about the usefulness of independent measurements, I agree.
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George,
You said "This Stereophile’s JA’s statement, is the typical case where a 25w amp like the ML2’s with doubling capable wattage current will drive a pig of a load like these Alexia’s and the OP’s speaker "to a given level" with perfection better than any 3000w class-d can." OK, "drive" is the issue you are concerned with, to the exclusion of the much more important question of what an amp SOUNDS like. A more powerful engine will DRIVE a truck better than a smaller engine, but this is irrelevant to what people here care about. My Mytek Brooklyn will have problems DRIVING a very low impedance inefficient speaker to very loud levels. SO WHAT? At 1 to 100 watts, it kills the ML2 for resolution.
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atmasphere,
Of course you can take my word for anything I say I hear. Also, because I am not in the business I tell things like it is without concern for politics. Actually, I use an EQ to drastically boost HF because as a violinist hearing things under my ear, I tell you that all speakers are hopelessly veiled and muddy compared to that. I cannot make any system sound as natural and truthful as the real thing, but my EQ helps a lot. My speakers are aging Audiostatic 240, and I add the Enigmacoustics Sopranino super tweeters in parallel at the 8 kHz crossover setting. The net impedance of this combination is a little below 2 ohms in HF. In combination with my EQ I need lots of power into HF with the inefficient parallel stat speakers. The Mytek will rarely shut down for only unusual passages in classical music, even with my crazy (to most people) requirements. Even my little Bryston 2.5B SST2 which clips on probably merely 50 watts at 2 ohms since the power supply is skimpy, produces highly detailed, fast, clear sound within its limits. For classical music before Brahms, it is totally powerful enough and enjoyable. Even for Brahms which doesn't have any percussion, it is powerful enough, used at sensible volumes. The little Bryston is not powerful enough for Mahler and cymbal crashes, but the Mytek handles all classical music well.
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Atmasphere,
While you and Ric Schultz are technically correct that higher impedance speakers get better performance from amps than low impedance speakers, this ignores the overwhelming superiority of low impedance electrostatics for most musical criteria, except in large SPL dynamics where the conventional dynamic speaker excels. If someone designed a higher impedance stat, that would be great, but the disadvantage of somewhat higher distortion (and it is still fairly low) into their very low impedance is vastly outweighed by their superior transient response, clarity, coherence, less coloration, etc. The old dictum is still true--the speaker is the most important element in the chain, with the possible exception of source quality. Get the best speaker you can afford, then get the best amp that will drive that speaker.
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Atmasphere,
You said, "But I don't agree about the 'best speaker you can afford' thing! The reason is simple- you may find that you have a preference for an amplifier technology- tubes for example- and if that is the case buying an incompatible speaker will simply be money down the loo. So- if you know what kind of amp you prefer, then get the best **compatible** speaker you can for it."
I say that no speaker is "incompatible" with any amplifier. A 5 watt tube amp may make great music up to 105 dB with an efficient horn speaker. But driving a 75 dB efficient electrostatic with small panels, it can make beautiful chamber music at SPL of 75 dB, which is the natural level of a string quartet, for instance. Suppose the listener wants to hear sweet mellow sound from the string quartet, then the more "compatible" higher powered neutral/accurate SS amp is not for him.
The more general point is that the sound character is largely determined by the speaker, closely followed by the recording. Most good amps today have superb specs and sound fairly close to each other. Any of them are much closer to theoretical perfection than any speaker available today, all of which sound hopelessly veiled compared to the real thing, although I come much closer with my electrostatic and EQ. The real advances in high fidelity should be in speaker design rather than amp design. Produce better electrostatic designs, rather than inferior huge curved panels of Sound Lab and Martin Logan which smear HF and bloat images. It is interesting how the new smaller Maggie LRS is creating a sensation. I haven't heard it yet, but the size is right. How about plasma drivers crossed over to electrostatic panels for lower freq. I heard the Plasmatronics speaker by Dr. Alan Hill in the early 80's. Too bad most of the market cares about big dynamics instead of accuracy and finesse, which is why these plasma and stat transducers are largely ignored.
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Atmasphere,
I follow what you are saying about how a voltage source SS amp invariant to impedance theoretically would sound bright driving an electrostatic speaker. But in practice I don't find this to be the case. Years ago, for fun, I put my tonearm leads into the line stage, bypassing the RIAA curve of the phone stage. Of course, that produced very bright sound due to the 30 dB boost at HF compared to low freq. With the stat speaker, impedances can be as high as 30-100 ohms in the upper/lower bass, and 1 ohm or less in HF. This is more than the 10:1 ratio you cite, but still nowhere near as much as the inverse RIAA curve. Still, according to your theory, the stat speaker should sound like a less drastic inverted RIAA curve, which I didn't find in the listening. Also, all dynamic speakers have marked variations in their impedances, and your theory would predict that a SS amp would produce markedly different sound from different speakers in relation to each speaker's impedance curve. But I have found similar tonal differences A/B'ing 2 amps on different speakers. For example, SS amps generally sound brighter than tube amps, which I have found to be true regardless of whether I used dynamic or stat speakers. I am puzzled by my different listening findings compared to your theory.
I wasn't saying that amps don't make much difference, because obviously I pursue finding amps that offer more clarity, etc. But it is clear that whatever sonic differences there are among amps, the sonic differences among transducers like speakers are vastly greater. This is also true of transducers like cartridges which are really inverse speakers.
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