Well, class A is not exactly ecologically sound design, that's true. But it is my only objection.
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All I know is the Sugden A21SE I’m running with at present is the best sounding amplifier I have owned to date, not that I’ve owned that many amps really but it’s also the best sounding I’ve heard apart from a Sugden Masterclass, yes it gets toastie but at 30wpc at 8ohm it’s got an amazing amount of kick, the kind of power amplifiers like the Hegel H190 with 150 watts struggles to match, but at the end of the day an awful large part of being an audiophile is thinking with the heart and everyone will always have their correct opinion, that’s what makes us spend silly money. 😂 |
Idk...my sugden A21se single ended class A sounds wonderful to my ears. Probably the best I’ve heard thus far. It somehow is adding something to the music that, at least to me, sounds more natural or organic. Maybe its in the design, maybe its added distortion...who knows? All I do know is that I’m either hearing or at least perceiving a noticeable difference in a good way. This is not to say that my Marantz pm14s1 sounds worse in any way, I’d rather say it sounds different. I will say that the sugden does seemingly run out of some breath at very high volume, where as the marantz seems to have more headroom. However, at a lower volume (where I generally listen), I gotta give it to the sugden. It is doing something right that makes me me want to keep on listening. Its a beautifully designed amp by the originators of SS class A, since 1968. Countless reviewers of the A21 have felt the same way about it as I do, so I don’t think I’m nuts. Is it the absolute "best" amp available?? Of course not!! However, for what it costs and what it does do, it does a darn good job. No bells, no whistles, no dac, no phono stage, no digital whatsoever, All Amp... Also not sure why people harp on how hot it gets..its class A! Always on, always ready. If I want to pay a higher electric bill, so be it. There are some much older a21’s still in use today with zero issues, despite the heat. https://en.m.wikipedia.org/wiki/Sugden_Audio#:~:text=In%20April%201968%20the%20A21,amplifier%20under.... |
you boys need to play nice....the concept of "which is better" is such a competative, guy-thing....listening to a system is about pleasing the listener; I hope we all recognize there is no "absolute' sound in reproduce music, and ones perceptions are subjective ...we should recognize that some "distortions" are "pleasing" to certain listeners. And some listeners cannot get past preconceived biases, and hear what they want to hear. At the end of the day, it is all about what pleases the listener. I know full well that my room is a serious limiting factor for my sound and I simply have come to accept that....as it stands, good source material sounds wonderful , to me, and that is what matters, I believe....I am not here to "compete" with others.....ENJOY ...... |
Class A amps (almost) always measure better, Also not true. AB can have vanishingly low distortion. Compare for instance Pass' class A designs. He deliberately designs for euphonic distortion. He does not make absolutely low distortion amps nor does he wish to. It's exactly his house sound. So, neither sound nor measurements are better universally by class. Class D for instance can best many Class A for distortion and low output impedance. Not always though. What is true is that the crossover distortion vanishes with Class A. Sound quality, output impedance, distortion, all vary greatly and overlap with other class of amps. |
Hear, Hear... jw944ts! I have, after almost 50 years in this wonderful hobby, ended up with "mostly" tube equipment, push pull A/B, with Martin Logan hybrids and auto formers (take it easy georgehifi, my preference, my system). Sounds great to me (and associates). My best friend(s) have older Morrison mono class A SS amps, with Morrison (new model) speakers. Sounds great to us. Our other friend, has Mark Levinson 300w amp and some European (German) stand mounts. Sounds Great. I think the point here is that, yes, there are general "rule of thumb" guidelines but.... there are no absolutes (class A is superior.... etc). Way too many variables and always an exception to "the rule". My take on all this... that it is a valuable endeavour to mix and match, swap equipment in and out, socialize and listen to music (and gear). As jw said...ENJOY.... |
Develop some awareness of the topic https://www.electronics-tutorials.ws/amplifier/amplifier-classes.html |
Dan D'Agostino also thinks distortion adds musicality to his amps. https://www.youtube.com/watch?v=JW7fg_yfza4 |
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For what it's worth, I have two Class A amps, a Reference Line Silver Signature (modded by Roger Modjeski, RIP) and a Plinius SA-103 (heavily modded by Vince Galbo Designs). Both put more than 100w into 8 ohms. I used to have Bryston 28B SST2, an AB amp that put 1000 watts into 8 ohms. I had all three amps at the same time, so I could easily compare them in my system, which includes PMC IB2i speakers (known to love Brystons). The class A amps sounded better by pretty much every parameter. The Brystons are long gone. What's more, the Plinius has a button you can press to switch the bias from AB to A. Class A sounds better, by no small margin. Again, FWIW. |
In solid state amps only a handful and in tube only a handful also they are incredibly difficult to make and unreliable due to heat generation because of the 10 percent efficiency. So most of the makers if not all stopped making them.This statement is false. We've been making class A amps for over 45 years. Reliability isn't an issue- that's an engineering problem, not something inherent in the class of operation. They are more efficient than 10% too- that's about a country mile off as the saying goes. |
"...that’s an engineering problem..." Are class A amplifiers significantly harder to engineer, or they are about the same but only bring some of the well-known things (heat) with them simply because of class? Also, how does efficiency of class-A amplifiers compare with other classes (ballpark figures)? |
Dear @inna : After all those posts you already know that class A not always sounds better. Some of the posts said that depends of amps design and I add quality excecution to that design. I have this first hand experiences with Mark Levinson amplifiers: its first amplifier named by them Reference ( and this is not a marketing name/model, when ML says that it's because it's a true reference and not MK like other products. ) were the model 20 pure class A monoblocks. Years latter they puts in the market the new class AB model 23 and things were that the 23 outperformed the Reference 20s. ML inmediatly took the problem and fixed with a modification in the 20s and then born the new Reference 20.5 but even with that experience Levinson again puts a new class AB amp in the market that was the 23.5 and wonder what: again the 23.5 outperformed the 20.5s and Levinson had to fix it and did it through the Reference 20.6s. I still own the 20.6 with some modifications by my self and a friend of mine and owned the 23 and 23.5. What made Levinson in his pure class A Reference 20 and latter in the 20.5? , they don't touch the output whole design but made the changes ( twice ) at the input design at the input circuit boards and through those changes the 20.6 outperformed the 23.5. Even that the 23.5 was very good class AB amplifier. Theshold had the class A SA-1 monobloks and at the same time Pass designed the class AB S500e. I listened both models several times and the class AB was a better performer. Crossover distortion not always makes the difference for the better. Design and excecution quality level to that design is really what it counts, it does not really matters if class A or class AB. Regards and enjoy the MUSIC NOT DISTORTIONS, R. |
Class A, class A/AB class H all sound great! Why so many mean people? My class H is the Carver Sunfire 600. Pretty sure it’s class H. She sounds great, pretty much unlimited power with that amp! Clean, open, great sound on all spectrums , bass, mids and treble are all superb! I especially love both taps, and switch quite often, depending the music I listen to. The tube sound tap, is great, makes my listening very enjoyable. If you love the sound o your amps no matter where they rate in class, a, a/b, h, d. Listen and enjoy. |
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Are class A amplifiers significantly harder to engineer, or they are about the same but only bring some of the well-known things (heat) with them simply because of class?They are not harder to engineer. Its arguable that they are a bit easier, although you have to be more careful about heat issues and the power supply has to be able to support the output section being on all the time, something that you don't get with AB amps. Of course class A is the least efficient of all classes of operation. The advantage is the output devices are often biased at the most linear portion of their curve. So if all goes well, they will make the least distortion. |
As a casual listening “semi-audiophile,” my journey took a delightful turn when I started digging through the story of the early Crown SS pro audio amps. I ended up scoring two PS 200s in decent shape for under $200 each, sent them back to them back to the Midwest for refreshing and thoroughly enjoyed building two different systems...a 6U rack system with modern processing and vintage Cerwin Vega/Jensen sub speaker combo...and the other a “rat rod” rig with nothing but an unpowered Shitt preamp and BT2 Bluetooth DAC with modern REL T5I sub and Onkyo towers both running off high output. We don’t play much volume around our home and cottage, so these venerable refurbished 90W Class A/AB/A+AB Crowns, both removed from churches, run in crisp Class A most of the time and present a surprising snd pleasing sound stage. Great fun and great value in the final analysis, FWIW |
Although Class D is the first amplifier topology that theoretically offers completely linear operation with 0% distortion and no power loss at 100% power efficiency, the commercialization of Class D audio amplifiers had to wait until the ‘90s when silicon (Si) MOSFETs with sufficiently good device parameters became widely available. https://www.powerelectronicsnews.com/opening-up-the-next-chapter-of-class-d-audio-amplifier-performa... I saw theoretical max in the post. Since this is all subjective I wouldn't trade classD for classA as long as each amp were designed properly and were used within their parameters. |
Really depends on the speaker in my experience. Went with the class A few esoteric 30 watts in my smaller room during a demo of a speaker I desired. Made a deal for the speakers and demo amp. Despite my current speaker 8 ohm 92 dB sensitivity the combo is awful. Still waiting for speakers to arrive From Scotland |
S’funny, one of the nicest class A amps I have heard is a positively antiquated JLH69. It can really sing with a pair of heritage Klipsch’s. There is something fundamentally ‘right’ about its sound that a lot of more modern amps fail to grasp. AB can sound great too. All depends on the implementation. |
I might be off here, but class A amps don’t drive lower impedance speakers very well either. Most class A amps aren’t stable into 2 ohm loads. Krell being one Of the exceptions.The class of operation has nothing to do with what load impedance the amp can drive. They simply aren't related, plain and simple. |
Reading all of the responses from a simpleton’s point of view is very interesting. But the ultimate measure for any piece of hardware is the one thing that’s totally unique for each person. How their complex inner ear relays information into the brain, which works out what’s pleasing to the listener. Not to mention the endless variables that change our hearing over time. You can’t tell someone there wrong when you don’t have their ear and brain. Never mind the biases we have from where and when we were raised What’s the best amp made? It’s the one I have. You may fire when ready |
Hello. Interesting debate. I’m in the market for integrated amp to pair with my Goldenear Triton 2+ speakers. In the next couple of weeks I want to demo Pass Labs Int-25, McIntosh Ma-352, Luxman 509/507 590/550 depends what dealer will have in stock and maybe even Arcam Sa30(first 20w in class A) I don’t care about measurements or numbers,all I want to hear is beautiful music. I rarely go over 85db in my medium size room so I think any of those can do that. A,A/B,G.One of them will win. Cheers |
@kren0006 wrote: "As a direct example, some feel that the Luxman 509X class AB at $9.5k sounds better than the Luxman 590axii class A at $9k. Can’t get much more absolute-busting than that. Same company, both integrateds with same features, essentially same price, both current products." === I thought that too (and I own the L-509X), but did you know the L-509X is both A and A/B? It delivers the first 6 watts as "pure" Class A then transitions to A/B for the rest of its rated output. I confirmed this with Luxman USA during a discussion of the L-550 (which is also a hybrid A, A/B, not just A) Quote from Luxman USA email ...The Luxman L-509x is an excellent amplifier. It is considered “top of the line” and most recently introduced Luxman integrated amplifier model. It features circuit and construction details/refinements not present in (earlier introduced) the L-550aXII and L-590aXII.Just tossing that into the pot for consideration. |
