+1 @mapman
What are the best GaN Amplifiers available today?
There have been a number of threads discussing the wonder of GaN and some of the individual amplifiers that have caught peoples attention, including those from AGD, Atma-Sphere, Peachtree, LSA, etc. Has anyone done a shootout against two or more GaN amps? If so, which did you prefer, and why? And on what speakers?
Also, of the one you preferred, do you prefer it over every other amplifier you’ve ever heard? If not, what non-GaN amp do you enjoy more?
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I’ve had no problem with various Class D amps driving speakers on recent years. I even have a $90 chip based Class D integrated amp driving original KEF ls50s amazingly well where I have seen other way more expensive amps fail at that miserably. As always YMMV. Like anything else all CLass D amps are different. So yes they can drive difficult loads well but you have to do your homework. The info needed to make a smart choice is out there. |
I asked Ralph this recently regarding his Atmasphere GaN amp and he said it has no problem driving a 2 Ohm load. |
Actually this one is easily measured (you don't even need test equipment, you can do it with your hand for Pete's sake) and it is audible for a simple reason. All toroidal transformers are supposed to have a very compact radiated magnetic field, but in practice they are a bit sloppy. Transformer manufacturers supply a mounting bolt with the transformer, but that bolt is always been a regular steel bolt and is magnetic. If you use it to install the transformer, it will be a magnetic short to the transformer. So you'll find that it heats up more than the transformer itself (you can feel this with your hand... you can see how laughable the idea is that this can't be measured 🤣). So its easy to show the difference in temperature and output voltage of the transformer when the magnetic steel bolt is replaced by a nonmagnetic stainless part. We've been doing that for at least 30 years. Fun fact: the bolts holding EI core (conventional) transformers together are also magnetic. They are usually insulated from the metal of the transformer and this does mitigate a lot of the magnetic load they place on the transformer core. But not all of it. You can reduce the temperature of a conventional power transformer by using non-magnetic stainless bolts (don't forget to keep the insulators!) and you can increase output power in tube amps slightly by changing out these bolts in output transformers for the same reason. You can see here that someone claiming this can't be measured hasn't even bothered! The issue with measurement is often figuring out what to measure, and then sorting how. For example, if you want to measure the effect a fuse or power cord has on an amplifier, you don't measure that fuse or power cord- you measure the effect on the amplifier. Similarly if you think that a certain tweak has improved the bass in your system you demonstrate this by doing a frequency sweep in the room, install the tweak and measure it again. A customer of ours used this technique to show that a certain filter capacitor he had installed in a power supply was not only improving the bass but also reducing distortion. He was able to show a correlation between the perceived improvement in bass and clarity of the system and his part replacement in this fashion; that the perceived benefit was more than just expectation bias. I can go on with other examples but you get the point. If you hear a difference, and especially if others report the same difference, then if you think about it you can probably figure out why that's happening and measure it. But you do have to think... I remember very clearly the first time I heard a power cord make a difference- I was at CES in 1990 and heard a set of Magnaplanar MG3s that had been modified with a wood frame made by George Cardas. It was an impressive frame and did wonders for the speakers. I asked him if I could play our MA-1s on them after hours, he agreed and we made it happen. The amps seems to have a prodigious ploddy bass on the speakers; George suggested a pair of his power cords, which we installed. The bass was instantly improved! Switching back and forth the difference in the power cords was not subtle. I bought the pair of power cords on the spot. It really bothered me that I could hear this but there was no clear cut explanation why, other than the mysterious claims that so many cable producers make. Turns out it was something simple: voltage drop across the power cord, easily measured. I sorted this out by measuring the output power, output impedance and distortion of the amp, which led me to measuring the input AC voltage at the IEC connector. Voila! Power cords are one of those tweaky things that a lot of people over on ASR will deny has any effect on a system's performance. Power cords are subject to Ohm's Law like anything else. When I see that kind of denial, I like to ask if they caused their hand to move and make the measurements they laud so often, rather than just blindly making a pronouncement. If there's no measurement they are no better than the subjectivists they denigrate.
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The only picture that I see of the inside of your amp is when you did the inteview for the SF Audio Society. You show the proto amp and it shows a steel plate on top of the transformer (or is that non magnetic stainless steel?) and a bolt through the transformer. Are you still doing the same now? Turns out that even a NON MAGNETIC BRASS BOLT will also completely mess up the sound (I discovered this just about 5 years ago....I thought, like you its because its magnetic....turns out any CONDUCTIVE material does the same sonic degradation.....plastic bolts are fine).....and of course, a steel plate on top of the transformer. also completely messes with the sound....and it also sounds best to get the field away from your chassis.(whether aluminum or steel)....this is why you glue the transformer on top of wood. You can hear all this. So, if you can? measure extremely small voltage output difference or extermely small differences in heat.....please explain why you would hear this as a SIGNIFICANT difference in sound. You cannot....if you lowered the voltage of your power supply by one volt it would not change the sound of the amp (I am sure you will argue about this). The sonic difference in removing all the hardware and floating the transformer above the chassis is that the sound is more open, more airy....more dimensional...more pure. So, do you float your transformer in the air with no conductive material around it? Please, do some serious listening tests.....you will see this is way more complicated than "a magnetic bolt versus a non magnetic bolt". Your rant about the power cord is complete poppycock. You have posted about this before in your defense of measurments. Of course, larger power cords have lower resistance....everyone knows that. However, ALL power cords using the same gauge sound different from each other and one brand of 14 guage cord might sound better than someone elses 12 gauge cord.....this is common knowledge......Is it your knowledge? Or do you think you just need a large power cord and be done with it. If all we needed is low impedance we would all have 4 gauge power cords. There are cable manufacturers that claim that the connector makes more sonic difference than the wire they use (very expensive wire). Can you measure the resistance difference between a home depot connector and a Furutech?.......maybe......and if you did measure a milliohm difference....is the one with lower resistance the best one sonically? A few years ago I manufactured a dozen amps using highly modified IceEdge modules. One of the first AC mods I tried was to listen to various AC inlets. First I tried the $1 Shurter inlet that many serious companies use. Then I tried the same inlet but Cryoed by Take five audio in Canada....$2.49 each......it was noticeably better......then I tried the Furutech $28 inlet that was pure copper, gold plated, cryoed and demagnatized......sounded much better again. Then I tried the more expensive version of that connector that has the specail plastic and Rhodium plating......this thing was forward and zippy.....not musical to me. However, some say you have to burn them in for 400 hours to really hear them. I don't have that much patience.....he he. So, I sold the amps with the cheaper Furutech and everyone was happy. So, how do you measure the differnces in AC connectors that can give us a reliable way to buy connectors? You cannot. This game is so much more complicated than distortion measurements, heat measurements, voltage measurements, resistance, capacitance and inductance. This game is infinite.....and the only way you know anything about sound is to LISTEN. Ralph would have us all buy 4 guage power cords and use whatever for line level (Mogami is fine, with him....a friend of mine started with Mogami and thought is was good...then he tried two others that BLEW away the Mogami). He has said over and over that balanced cables make no difference in sound. Even his customers hear otherwise. You have to listen to know....you have to listen to know.....and listen with an open mind.....an open mind. |
A new design must be made with a complete set of measures in mind...This set of measures are trade-off choices... No design is perfect... But designer dont tweak by definition...If they do they must integrated their tweak in the design... With or without set of measures but more often then not designer are engineer and physicist in some case as for my headphone, they dont tweak, they use well known scientific principle and they apply it ... But this headphone for example so innovating and amazing it was designed needed some modifications FOR ME : I throw off the protective plastic thick grid, i changed the volume of the shell chamber by using other pads than the original one, I put inside it two products to damp its vibration... After that and some other rectification their design was IMPROVED for my ears...So much so that upgrading it appear preposterous to me... I respect a lot Dr. Gorike the physicist who design this marvel... But any design can be improved... But i will not play with amplifier electronics components by lack of competence and it seems to me less necessary But i even tweak my Sansui Alpha for the better with various minerals OUTSIDE of his body 😊... No serious designer will do that or advise such a "ridiculous thing" ... Designing is a serious enterprise with his own ethic and secrets... Tweaking a component if the user like to experiment is always possible... Anyway any system must be embedded mechanically , electrically and acoustically ... These controls can be methodically applied or applied discretely and called "a tweak"...
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This is a misrepresentation; a strawman and is false by definition. I did not made the statements implied in this post nor have I received the feedback he implies. I've explained that voltage drop is part of why power cords sound different elsewhere on this site. I've also mentioned that there is another variable, which has to do with bandwidth. WRT balanced lines, I've pointed out many times that if the equipment using it does not support the balanced standard (very common in the 'high end audio' world), differences in cables will be easily heard since the shield of the cable and the dielectric (insulation) have become part of the 'sound' of that cable. The Golden Age of Stereo recordings (1958-1960) demonstrates that the balanced line system works quite well, unrivaled by single-ended connections. Its one thing to have an open mind; quite another to ignore fact in favor of made up stories. |
I don't know about feedback but I have seen a couple of posts by your customers saying they hear great differences in balanced cables using your balanced gear. There is no made up story....you have claimed over and over again that balanced cables make no difference (using true balanced source and load)......you just implied it again....case in point. All cables sound different no matter where and how you use them.....this is fact....dicernable by your ear.....by anyones ear. I never said you told people to buy 4 gauge power cords.......it is just what you imply. There are tons and tons of factors in a power cord that effect sound quality. Resistance is one of hundreds....Bandwidth? You need wide bandwidth to carry 60 cycles? Actually, you do....and you don't......long story. What about all the other factors? You don't go there, eh?
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Getting back to GAN amps. I got the used Peachtree GAN400 (400W) today and replaced the modded Peachtree GAN1 (200W) on my Magnegan LRS+. Those ratings are for both 8 and 4 Ohm. The LRS+ sounds more alive with that additional power, and also the inclusion of my KEF KC62 sub in the chain. The LRS+ certainly does like power. It sounds the best with my CODA #16 amp but the GAN400 gets close enough. Most importantly the sound is very enjoyable for $1200. The GAN400 does sound more powerful than the LSA Voyager 350 GAN. I had the 350 GAN modded by Ric and it was better than stock. If I decide not to 'upgrade' (or sideways move) to a Class A/AB amp I will send the GAN400 to Ric to do his magic on it.
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Mr Ralph is a good engineer and I often find his posts interesting and useful. A very effective marketing tool as well. Mr Charles Hanson, another good engineer, before he passed (RIP), stated on one of these forums that Mr Ric is one of the most knowledgeable digital engineers in the county. So just because Mr Ric is primarily a mod guy with an unconventional personality, don't discount what he has to say. He certainly has better ears than most of us. I've used him several times over the last decade or so. He's a straight shooter and an honest guy. He stands behind his work. I've always been pleased with the results. Very reasonably priced, I might add. He's also interesting in other regards. |
Great post! thanks... The two are interesting and competent... But between people sometimes discssion may be "heated" a bit... Anyway these two makes great contributions very few of us can match... i respect the two person in the utmost possible way...
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If you look at the available info it appears the best Class D amps measured so far are not GaN. Moral of the story is GaN alone does not necessarily mean best. Hypex and Purifi and a few others are not GaN yet and still seem to measure better and are at or near the top overall. GaN is clearly a promising new technology but still may be a ways from full realization. I’ve heard both AGD and Atmasphere GaN amps and both sound very good to me but that is just my subjective assessment. Neither may be most cost effective. |
@mc1969 what do you base saying that is the “best” on? |
Mapman, Using a lot of feedback to create super low distortion numbers does not make a product superior sonically to an amp that has less feedback. Ralph uses way less feedback in his amp than Purifi and it probably does not measure as well as Hypex and Purifi. Does not mean it is less REALIZED...or less good sonically. The GaNfet analog class d modules used by Peachtree and LSA were designed by listening and they preferred less feedback.....therefore less good static measurements. There are no fully realized products....absolutely none.....at any price range. As soon as you buy the latest $100K amp another one comes along that is said to be better or the original amp manufacturer brings out an "updated or new" version. If you go to 10 audio you will see a review of the Purifi based NAD amp ($2K) and my modded VTV Purifi amp ($1600). He gave the NAD a 7 and mine a 9.5 bordering on 10. The execution has a tremendous effect on the sound.....sometimes more than the amount of feedback or the modules being used. Truth is what you hear.....it is what you feel.....it is what you are.. |
@ricevs nothing wrong with subjective reviews except the fact that each persons subjective opinion may be different. |
@mapman read the reviews. |
The good ones for that product or all the others with similar food revues? Being a bit cheeky…..can you point me to one that indicated it is the “best”? Thanks.
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I have not had a Class D amp that bettered my best Class A or even AB amp yet. I have kept it under $3K for the various Class D amps I have tried. However, for certain applications, like my office system, with the LRS+ it is a lot of Class A or AB dollars to get to the level that I am hearing with the PeachTree GAN400, especially used. I am listening to a long playlist of Sinead O'Connor music as I type this, and it is goosebumps. I am sure it is 99% her voice but the gear does add to the beauty of hear voice. |
Actually I have. Bandwidth is required to pass current in the short period of time at the peak of the AC waveform when the power supply filter caps can charge. If the bandwidth is lacking in the cable the caps will not charge properly. I have explained this elsewhere.
😂 When someone is willing to contradict themselves in this manner, its not about fact. Its about making the other person wrong. It is time to stop with the trolling.
This is a comment that I often see made by people that purport SETs. We might have a difference of opinion here; mine is that the equipment should not add or subtract WRT to the beauty of the recording. In this way, the more neutral you can get the equipment to be, the more it can bring out nuance in the recording without editorial. |
I do not think we have a difference in opinion regarding the type of gear we prefer. My goal has been to go to neutral and let the source dictate. My Livingroom system is Benchmark LA4 preamp and DAC3B into a CODA #16. Only the CODA is really not super neutral. It is slightly warm. I wanted power for that system and the #16 delivers. The LA4 is a beauty to my ears, it adds the least of any preamp I have heard. My office system is also geared towards neutral with a Holo Serene preamp (very similar to the LA4), Schitt Yggi+ LM DAC and now what I feel is a neutral sounding GAN400. The even more neutral Benchmark AHB2 sounds better to me than the GAN400 but the GAN400 is a much better amp for the LRS+. In fact, the AHB2 is my fav amp but it is not guaranteed to drive everything. BTW - Sinead has such a beautiful voice that even on a transistor radio I would get goosebumps listening to her.
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Neutral is good for details and realism... My Sansui Au 7700 so good it was , sounded less neutral than my Sansui alpha , it was not so less sensible in my speakers/room , but with headphone i even change my french TDA 1543 Dac NOS which was more than good , for a more neutral Hidizs dac and the Sansui more neutral amplifier , because my headphone asked for the highest possible cleanliness and neutrality... They are way more refined than my speakers were so good they were in my room .. Then ideally we need neutrality as an end goal... |
That is interesting. I wonder how the AGD or the Atmasphere amps compare to some Class AB amps that are highly rated in the <$10k range. But I have also read reviews, where owners were happy with the GaN amps and had no remorse replacing the AB. Of course, everyone's experience is different. |
If someone posts here on or some other thread I read and I feel that information is not "experienced truth" then I will make sure I post my experienced truth so people can decide for themselves (with listening tests).what is actually true. The more something gets posted the more people will think it is true. Because someone has a good rep or says something a thousand times does not make it true. I hope you ALL will stand up and be counted. Every TRUTH needs to be heard. Every one of you is valuable....is beautiful. Do not let me or anyone dominate a discussion....without telling your truth......And, hopefully, your truth is not a philosophy or opinion based on non experience.......but a TRUTH based on critical open minded listening tests......the only real TRUTH in audio. In life, the big truth is that we are all magnificent.....beyond our imagination.....we are infinite beauty, love and joy.....it has always been so and always will be so. Is that my philosophy or my experience? Both. Blessings to all! |
I spent about 12 hours today listening to the GAN400 on the LRS+. It was really good, many times I had to stop my work and listen. I am so glad that I got this amp back. However, there is a hint of hardness on top that my very neutral system conveys. Though, it is not something to lose sleep over. When I had my CODA #16 on this same system that slight bit of hardness goes away. You also get even more thump with the CODA #16 (150 watts vs 400 for the GAN400). The GAN400 is close to being one of my best amps, just not totally there yet. In stock form it likely the best Class D I have owned. I do not want to damn it with faint praise. It is an amp to check out and maybe with a different preamp could be perfect for a lot of people.
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I tried the Peachtree GaN400 based on the glowing reviews and wasn’t at all impressed. It sounded like typical Class D sound—no balls in the lowest octaves, clear and articulate but also fatiguing. It was a surprisingly noisy amp as well. A local audiophile friend of mine auditioned the Orchard Starkrimson and he wasn’t impressed with it either. He preferred his other amps which had retailed for similar prices. Similar to the Peachtree, the way he described its sound aligns with what I associate with typical Class D sound. In other words, no notable sonic advantages over a competent Class AB amp. I’ve determined that the problem with forum anecdotes with regard to amps is that many are lacking a good point of reference. Someone will chime in saying that an amp like the Starkrimson powered their Magnepans or ESLs well, yet this person probably wouldn’t say that had they compared the amp to a big Krell on the same day. That or they will be comparing these amps to a mid-fi offering from a competitor. Suffice to say I suspect GaN FETs with regard to amps are mostly another flash in the pan technology that hasn’t really moved the needle. There may be exceptions of course, but I am highly doubtful at present. |
I have not heard the Peachtree but from what I have read it is just OK at best. GaN got a lot of hype early on here. It is a technical advancement but no one thing alone assures a superior product. It’s all in how well designed and implemented a product is overall. It usually takes some time for engineers to fully realize any new technology fully. So the rule with new tech is always the longer you wait the lower the risk. New technology gets done better and often more cost effectively over time.
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@helomech Reference is a big deal IMO/IME. I use LPs and CDs that I recorded and mastered myself. It helps having been at the recording session. @mapman GANFETs have been around since 2009. They became much more commonplace about 2016; at that point most of the major US players had their own version of the devices and they became a lot less expensive.
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@helomech Hey man, Stick with your class A/ AB Amps. But Class D is no flash in the pan. They are becoming an ever increasing market year after year and are starting to take a BITE out of your A/ AB sales. Aavik..Peachtree...Atma-Sphere...Jeff Roland....Orchard...AGD.....good stuff and MORE MUSICAL to many than A/ AB. I do enjoy a Big Tubed Preamp with a ClassD Amp however. |
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I've got a Technics SU-R1000 which I think is pretty brilliant and is the first "digital" amp that I have really liked. I also had its baby brother in to play with for a couple of weeks and thought that was excellent as well. I had a NAD M33 for about three months and couldn't get rid of that fast enough. It's tough to compare the Technics to some of the others because of all the additional features that it brings to the table, so not really apples to apples. There is a gentleman in the area who has the AGD monoblocks and I would love to spend a day with him comparing the Technics and the AGD. I may see if my dealer is willing to loan me his AGDs for a long weekend as well. I'd also be interested in comparing the Peachtree with the Technics G700M2 as they seem in the same price ballpark. Sorry I can't offer more, I just have not heard any of these in the same room with the same equipment. |
I am comparing the Peachtree GAN400 with my CODA #16. In the past, have compared the CODA #8 with KRELL Duo 175XD and the Voyager 350 GAN in the same system at the same time. The PeachTree GAN400 is not too bad at all. I like the other amps more (except the Voyager 350 GAN) but not MUCH more. All 3 GAN amps I owned were better to my ears than the other Class D I owned from D-Sonic and NAD (Master series). The modded GAN1 by Ric gave my CODA #16 a good run. The CODA #16 is more powerful, and my speakers could use that power, so the #16 was the winner. Tonight, I am going to re-try the GAN400 in my larger Livingroom with my Yamaha NS5000. I will move the CODA #16 to the office with the LRS+. I have visitors coming for 4 weeks this weekend and it maybe safer to get the CODA out of the line of fire. |
Firstly, I referred to GaN FETs as a flash-in-the-pan technology, not class D as a whole. Secondly, I didn’t claim all GaN amps will necessarily perform poorly, merely that I have considerable doubt that any of them are really noteworthy. Lastly, the primary reason class D has been gaining market share is that more manufacturers are adopting the technology as a way to save on both manufacturing and shipping costs. Unfortunately, many of them choose to not pass the savings onto the customers. That and class D on the whole has improved in sound quality over the past couple decades, and some do indeed approach the performance of decent AB amps. However, the majority are still rather sterile and lacking in dynamics. Thing is, many “hi-fi” manufacturers are merely in the game to maximize profits. If sacrificing 10–20% of performance vs an AB counterpart allows them to do that, you can be dam sure that’s what they’re going to do. They also know that the majority of people purchasing these amps don’t have a decades-long history of obsessive gear flipping. These are often people looking for a simple, lightweight and unobtrusive solution with impressive specs on paper, and have little reference by which to judge performance. That and auditory memory is generally unreliable. So unless the listener A/Bs their latest/greatest class D amp against their past class A-AB amps, it’s unlikely they’re going to notice the shortcomings, and just as likely their expectation bias will lead them to a skewed conclusion.
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helomech....I've A/B'd the Aavik and Peachtree against the Belles SS , low watt tube amps, 845's....KT88's and class D sounds More Musical. And the Manufacturers are Not trying to rip everyone off as you prescribe....but offering alot of Value for your $$$$. You are just a plain old Class D hater, and that's fine. To each his own. But us Class D lovers will just keep Enjoying the Music ! There is a market for both Old and New technology. |