The Future of Audio Amplification
John Atkinson got the following measurements for the Cary Audio SLI-100: - 3.2 watts @ 1% distortion, into 8 ohms from the 8 ohm tap. - 22 watts @ 3% distortion, same. - 100 watts (Carys’ stated output for the amp) @ 10% distortion! - 1.2 watts @ 1% distortion, into 4 ohms from the 8 ohm tap. - Output impedance from the 8 ohm tap: 4.4 ohms @20Hz and 1kHz, 4.2 ohms @ 20kHz. Retailing for $5995, that is very poor value. I would much rather own an Atma-Sphere S-30 or Music Reference RM-10 Mk.2. |
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To step back into shallower waters here: So much of our world has become increasingly visual and on-demand. Screens proliferate and dominate. I can say the under-25 generation, having taught them for 20 years, can be even more capricious visually-reliant than ever, and streaming files has long since replaced object permanence. And yet music plays as large a part in their lives as it did in ours. In fact, I would say that many teens and 20-somethings have a larger musical palette in their playlists than most of the mixtapes we had. But the idea of having a "listening room" is a superfluous concept to most Americans, especially the ones with too much month at the end of the money. The idea of assembling a system costing 4 and 5 and 6 figures just for listening to music, especially nowadays, is pretty alien and unsympathetic. And since music has become transient files; since much music is listened to through ear buds and in cars; since Alexa and Siri, Sonos and Spotify, are cropping up in kitchens and living rooms everywhere; and since glittering OLEDs and other screens, including tablets, phones, and laptops, now dominate consumer consciousness, I can understand the aging of the audiophile. Audiophilia is a niche interest anyway, like any dedicated hobby. And if a soundbar and an Onkyo receiver from Crutchfield or Best Buy is enough for most people, I can't see amplification expanding like it did 30 years ago, especially in America which seems to favor the multi-chassis set-up. |
I think it's pretty safe to say that an amp that makes 10% distortion at 2 watts isn't even hi-fi by the definition of the term.@kosst_amojan That is true- do you know of such an amplifier? |
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I recently tried two class d amps in my own home, I do every five or so years. One was made by a small Japanese company, and remarkably good, but as the week went on, I turned it on less an less. The second was also interesting with more features but it didn't bring out the midrange magic that I love about my speakers and it sounded a bit hard and flat. For me, if I was limited to class d, I wouldn't listen to music as often. Now what I would accomplish with that additional time is more interesting than if I should feel shame for liking one more than the other. |
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Luckily the tube amp industry is alive and well, and should be thriving for many years to come...If I'm fooling myself by enjoying a tube preamp, a single ended tube power amp, and efficient horn speakers, regardless of the specs (I honestly don't have a clue what the actual specs are for my Dennid Had power amp), it makes absolutely no difference to me what anybody else claims about how this stuff sounds in my home. That said, my Class D bass amp is fine...I just patted its little head and told it to not be intimidated by all the tube amps around it. |
Having said that, Class D is the future for better or worse. There is quite a bit of cost savings involved for amp makers. They can be pretty good with a tube pre amp as a bandaid.The main reason class D is the future is simple- the semiconductor industry really doesn't want to make linear devices so much anymore- not like they did in the 70s and 80s! Very many non-audio applications are better handled by switching or digital circuits that were handled by linear circuits just a few years ago- and now audio can be done that way too. |
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Plasma TV has a tube like sensitivity in warmth, color and engaging the viewer. I’ve moved on to top of the line LCD TVs with higher resolution and brightness, a solid state like sensitivity. OLED TV is similar to a combination of the two prior technologies. Each type has its own limitations (LCD-picture uniformity, viewing angle, OLED-brightness in white scenes, motion judder Plasma-heat , resolution). |
Class D manufacturers, big and boutique, have years of experience / dollars tied-up in this technology. They are 'here' to make money. They won't chase a doomed topology this deep into the proverbial rabbit-hole. For now Class D makes dollars and cents, until something else comes along. And when it does, I'll be checking it out too. |
Class D amps sound cold and analytical to me. Maybe its all the feedback or the output filter. Meat is ultimately taken off the bones somehow. Having said that, Class D is the future for better or worse. There is quite a bit of cost savings involved for amp makers. They can be pretty good with a tube pre amp as a bandaid. I still have never seen a LED TV that can come close to my plasma. Plenty of people will say that LED has gotten better and surpassed plasma. I guess it comes down to what we value and what properties are important to us. Class D and LED both win in efficiency and that is extended to form factor. |
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John Atkinson measured PS Audio's M700 monoblocks ability to produce 700 watts at 1%, and over 100 watts at 0.005%, both figures into 4 Ohms at 1K. At 30 watts into 4 Ohms, which many of us never exceed at normal listening levels, that number fell to 0.002%. From 20 to 20K at 20V, that number never rose above 0.2% into 4 Ohms; the figures were better into 8 Ohms. Not that distortion tells but a part of the story, is something not to worry about with well-designed Class D amplification. |
The Tad Evolution class D amps specs quote 1% distortion. I believe most amp designers look to minimize distortion, and I’m sure TAD does as well. I use Spectral and am happy with the lack of distortion,incredible dynamics,nuance,faithfulness to the waveform(read music) and emotional connection this allows. I’m surprised that some argue Class D is equivalent; but we all hear differently and have different sensitivity to distortion. As I listen to live music often; my ear is sensitive to sounds that don’t reflect live. One poster mentioned he found “live” music flat and boring. Obviously there are positions for everyone. If one grows up listening to mp3 perhaps they’ll gravitate to that for a lifetime? I can’t imagine it though. |
IMHO, the underlying question to the future of class D is: Who is going to buy super exotic (expensive) USED amplifiers? Recalling the TAS March 2016 review of my Audio Alchemy stereo amp and dac/pre @ was $1995 each. The reviewer, Robert Harley (gave them Editors Choice Award) compared their sound to the Soulution amp/pre which I think was priced near $60,000: the reviewer noted that both were designed by Peter Madnik, and that the AA components were not sonically that far off of the uber expensive, and highly praised Soulution components Here's a great quote from erik in his AudioGon class D thread: "Sighted or blind, I cannot hear a difference between them an Parasound A23s. None. Zero. Nada." Now I owned Parasound A 23, several W4S stereo/mono/ multi channel amps, Emerald Physics 100.2 SE monos and now my Audio Alchemy stereo amp, and I can definitely hear the generational improvements, and the AA (apparently with HypeX modules) stands way above those that I owed. The AA amp had considerably more wallop than the 4xs as expensive (MSRP) EPs, which can often be ha for ~$2000 the pair these days Snippet from Stereophile August 2016 (according to review the stereo amp is essentially the same topology as the monos): "Madnick told me that, inside the DPA-1M, the signal is fed to a differential pair of JFETs feeding a low-power MOSFET driver stage. The circuit is servo-controlled to cancel any offset and to avoid having to use coupling capacitors in the signal path. This input circuit is powered by a dedicated power supply with ultra-low-noise voltage regulators. The class-D Hypex output module is powered from a switching power supply. The DPA-1M is a bridged design, which Madnick considers "the best-sounding way to do it." Of course, the sonic characteristics of the DPA-1M depend not only on its circuit topologies, but on the choice of specific components, PCB layout, and fabrication materials, as well as the selection of internal wiring and, one assumes, various proprietary factors. There was certainly nothing about the sound that screamed "class-D." In fact, had I been told that I was listening to a high-power class-AB amplifier—the kind that would require the help of a friend to lift it—I would have had no reason to doubt the truth of that statement. Theta comparison; And so, in a more modest way dictated by its price, is the DPA-1M. Like the Prometheus, it produced no artifacts, and added none of the "clinical" sound for which class-D amplifiers are often criticized. (FURTHER >80% OF THE SONIC GOODNESS AT 1/3 THE PRICE!)" So, whereas the older class D left many of us wanting, the current and near future of class D is such (IMHO) that people who own uber expensive A/AB amps will already have a hard time getting pennies on the dollar Read more at https://www.stereophile.com/content/audio-alchemy-dpa-1m-monoblock-power-amplifier-page-2#X4UzH1ZEC5... Read more at https://www.stereophile.com/content/audio-alchemy-dpa-1m-monoblock-power-amplifier#DaPTJ23tBl4br8kO.... |
While I have a dedicated listening room I built 25 years ago, I made some major errors in construction. It is good that it has a 6" rebar reinforced slab, 8" plates with staggered 6" studs every 8". Survived a 6.9 earthquake with no damage (or to the rest of house). However, I also made it vaulted from 8' to 11'6", have large multi-pane wood casement windows along both long walls and behind the speakers and dual layers of screw attached, non-staggered jointed 5/8X drywall on walls and single layer on ceiling. Also, the room designed to have 25,000 records now has 42,000 records. I was able to tweak the acoustics to sound very good. Without treatment, slap echo galore but definitely no problem with sound in or out of the room. In 2 months, I'm moving to another home and will convert 2 of 4 oversized garages dedicated as a sound room. No windows, flat high ceiling, superior insulation Sure, it's 40% smaller space but at least it will be dedicated to sound only and built better for it than in 1993. The records/cds will be stored in the adjacent room. We will have a large family room for video and a small audio system in the large living room. I would have built a dedicated larger listening room but for the 2017 City of LA law cutting in half the floor area ratio. That small living room system has a small high end CD player, really small sub-miniature tube pre-amp and a voltage regulated (non-ultralinear) redesigned Dynaco ST70. Fits on a small rack. Almost like a streaming setup size. Only the speakers are medium size Legacy Signature IIIs. |
Yesterday I visited a friend’s house after I was invited to check out his new TV. The price tag was staggering, less than $800.00. The picture was gorgeous and I could stand way off to the side without any distortion (or very little). 72" screen I think he said, or was it 65", anyway it was big. We started talking about screens and price tags only a couple years back. Audio of course came up as he owns one of my systems and we talked about how audio has made huge changes as well. A little over a year ago he dumped his big high end system for my simple designing and the improvement was not small. In fact just one of his components paid for his whole new setup including his home theatre. He has made the comment, more then once, of how listening has become so less expensive then a few short years ago. Sometimes when I read here, it feels like the guy hanging on to his old tube 32" tv weighing back breaking amounts, that no one wants to help him remove, and he can barely give it away. The mentality behind hanging on to the heavy tv is very similar what HEA is going through today. Huge space heaters taking up floor space are going to continue to decrease no matter how much sentimental value our generation places on the good ole days of plug and play. In the future there is still going to be dedicated rooms, especially outside of the US where they take the time to dedicate and aren’t trying to living room-ize their audio system (which never really made sense). Here in the US though the path is clear and will remain steady on it’s course. Also let me say this. Picture yourselves being 25 years old now, in todays world. Your dedicated room is going to be a lot different from the way it was way back when. There are more dedicated rooms now then back when we were doing our thing. The major difference is, now they are called "dedicated gaming rooms". I have no doubt listening rooms are on the rise. But this is different from equipment collection rooms. Michael Green |
The title of the thread is The Future Of Audio Amplification. The future is here now. It includes efficient toplogies that waste little energy as heat to drive loudspeakers. The future may improve from the current 85% to 95% or higher, but will certainly not incorporate far less-efficient designs such as Class A/AB. |
My system retails for over $24,000. I have friends whose systems retail over $300,000. I've been to CES and the Rocky Mountain Audio Fest numerous times. That said, the only time in my life that I've ever actually been physically moved to tears while listening to music was through my iPod. All this talk about amplifier technology is BS. Just shut up and listen to the music and enjoy it. |
Strictly speaking, encoding is not used in Class D. There is no conversion of one type of data to another. Instead Class-D relies on feedback, and a great deal of it. It is a comparative technique.Thanks pretty funny! :) Feedback (self oscillating) is one of three methods of encoding. The others are PWM and sigma-delta (Pulse Density Modulation). PWM allows the designer to build a zero feedback circuit. Some form of encoding/modulation is of course required to make a class D circuit. Strictly speaking :) Since you think this is all hand waving, see: https://www.analog.com/en/analog-dialogue/articles/class-d-audio-amplifiers.html (a short introduction to class D amplifiers by a manufacturer of class D amplifier ICs) |
Strictly speaking, encoding is not used in Class D. There is no conversion of one type of data to another. Instead Class-D relies on feedback, and a great deal of it. It is a comparative technique. That’s the nature of Class D and why it remains overall an analog process. The Technics uses no feedback. It has at least 3 processing steps: 1 - Initial encoding from Analog to Digital 2 - Signal processing(alters the input signal to match the speaker behavior) 3 - PWM Away with your nonsense, but I expect you will write four pages of barely related word salad to reply. |
There are also some amps like the latest Technics SE-R1, which are true digital amplifiers in that they convert everything from Analog to Digital, allow for phase and amplitude correction in the digital domain, and then produce an output based on a PWM output stage.Just for the record Eric, such an amplifier is a hybrid. Pulse Width Modulation is an analog technique. In any Class D amp, some form of encoding is needed, and PWM is probably the simplest means.Even if the amplifier is computer controlled to adjust its encoding scheme to accommodate various codecs (in effect a DAC that can drive a speaker), ultimately its still class D and thus also analog. |
A good tube preamp with tubes to taste and coupled with a great SS power amplifier is IMHO the best thing since sliced bread. It is like having your cake and eating it. Great SS amplifiers come in various topologies - overall design being most important - but I seem to like MOSFET output stages most and Class A. As far as fuses go....well I stay clear of such garbage boat anchor components - anything that changes audibly due to a change of a fuse is obviously a hopeless design to begin with. Good luck to those who own such ridiculously finicky pieces of equipment. |
Why is it that electronics designers like George and others who post are so far behind the rest of the audio world? Are they afraid their designs might not be perfect? Are they afraid they might have been wrong all this time? They don’t like eating crow? What we have here , gentle readers, is a remarkable stubbornness and contemptuousness on the part of some electronics manufacturers to acknowledge the superiority of aftermarket fuses, even in the face of overwhelming evidence. But also, belittling fuse manufacturers and customers. What evidence? You know, like 80,000 fancy fuses sold. Hel-loo! Wake up and smell the coffee, guys! ☕️ |
but to have friendsWho in gods name would want a "snake oiler" as a friend. you must play niceWhy play nice with the "snake oil" pushers here, they just have their hands in the gullible's pockets, they are con men and need to be exposed not pandered to. There's too much of this snake oil BS creeping into hiend audio because of the money to be made (eg $250 for a 20c fuse) and then being told it's directional and also needs to break-in for 200hrs.!!! It just drags audio down, just show some of this "snake oil" stuff to any electronic genius who has nothing to do with audio, and he will laugh in your face. |
How am I playing both sides of what fence?The selling propaganda fence of http://tweakaudio.com/ $60 plus audiophile mains fuse. If there a buck to be made from the gullible with snake oil products, mains fuses would have to be at the top of the list. I will not longer respond to you, George. I’m devastated |
George, You are acting more hysterical by the minute. How am I playing both sides of what fence? I clearly state that audiophile fuses are a good thing. No two sides here. The first two questions above were for you! Maybe you cannot read or comprehend well? I will not longer respond to you, George. There can be no conversation worthwhile with someone who only listens to himself. George, I wish you well, but to have friends you must play nice. A world with love and peace is what I create.....more and more. What do you want to create? Bless you, and may you find the higher love and light! Love yourself and everyone. We are all holy and beautiful....every single one of us. |
ricevsI don’t take **** from someone who has posted what he said about mains fuses seriously, and if you want to keep any cred at all, I advise you that you shouldn’t either. But then some remarks you’ve made about mains fuses, are dodgy to say the least, but then maybe you want to play both sides of the fence for a reason. |
So, if you believe "audiophile" fuses sound different and better than stock fuses, you are crazy? So you attack someone because they have a different belief than you? George, you are treading on thin ice here. You may get yourself banned for this kind of unkindness. I heard the distortions of fuses back in the mid 80s. This is not new. The latest fuses make a serious beneficial difference in a serious audio system. Anyone can hear the difference. Your class D or any other class of amp will sound better with Synergistic or Audio Magic Fuses. However, this is not a thread about fuses, but Class D amps and their future. I don't believe any Class D amp today is state of the art. Some of them are fantastic and better than other amps within their price range but we have lots to go in this dept. Just like digital it is a new medium so will take a while to mature. But in the last five years they have leaped from meh to OMG. However, even the coils and caps on the output of Class D amps imprint a sound. Most all coils used are just ordinary copper......If you make the coils from OCC wire and cryo them they will sound better. No one has done this. The caps in the output filters need to be world class or veiling will happen. These same caps on the output need their outside foil oriented to ground. No one is doing this....except me. The game in never ending. What is really cool about Class D is that you can get an incredible sounding amp right now for way less than those 100 lb. class A monsters, so you can spend more money on something else in you system that makes more difference (including better fuses in all your gear). |
fleschler626 posts12-13-2018 11:31amThat’s very rich coming from a "fuser", water off a ducks back coming from the likes of you. " I have both Black and Blue fuses and prefer the blue overall. It was easy to tell which fuses were stock as the difference is so great What a load of **** |
