I have not listened to the Technics SU-G30 yet. By reading the product page, it is evident that this is a fairly complex device, and that GaN transistors are a small component of the overall design. It is outwawrdly not possible to draw definite conclusions as of the relative contribution of GaN to the performance of Technics SU-G30
Worth pointing out that GaN transistors are not particularly new. Prototypes have been demonstrated as early as 1993... That is some 25 years ago. GaN-based transistors have been commercially available in one incarnation or another since 2006. See:
Nor GaN are the exclusive domain of Niche companies: major semiconductors fabs, such as Panasonic Industrial Devices, offer Gan transistors and GaN-based assemblies:
Relatively novel is only the application of Gan to high end audio amplification. If more amplifier designers adopt GaN, The next couple years will tell if transistors based on some forms of GaN inherently correlate to class D modules and circuits that contribute to enhance the audible performance of power amplifiers beyond the current state of the art. Or if the advantage afforded by the application of this semiconductor technology is purely a theoretical one. The danger of overoptimistic disconnects was nicely expressed by Mr. Berra:
"In theory there is no difference between theory and practice. In practice there is."
Yes, personalities abound in these forum threads. And yes, folks have what one might call “signature statements” that amply showcase their strengths and faults.
From what I can tell reading posts is that not a lot have actually personally heard this newer GaN-FET tech implemented into a class D audio amp design. So while the likes of AGD, Technics and Merrill might in principle sound terrific based upon this newer tech based upon the tech’s inherent theoretical advantages, they may also suck in real world implementation due to other designs flaws.
I’m not saying that they do suck and that the older MOS FET tech operating at lower switching frequencies are still king of the hill in class D land. But one ought to be careful in proclaiming one design implementation dead based upon merely theoretical considerations of a newer FET tech design.
A few of us here on Audiogon, myself included, have crossed paths with georgehifi and some of his dubious statements/theories about the current state of good class D amps utilizing MOSFET transistors. I understand your frustration since I also understand, based on using multiple good class D amps in my system for several years, that I completely fail to detect any of the sonic shortcomings that georgehifi claims exist on my amps due to traditional FET transistors, the switching frequency being too low and the filter used to remove this switching frequency being of poor quality. Now, I just picture him walking aimlessly around an Australian city in a bathrobe and slippers, having just walked out of some institution attempting to treat his rare condition, continuously mumbling to himself phrases such as " switching frequencies too low!" and "better output filters needed!". Occasionally, he stumbles upon an internet cafe and places posts on Audiogon. As I see it, however, the truth is that these new fast GaN FETs do have the potential to even further advance class D performance. Perhaps higher switching carrier frequencies will be beneficial, too. I think it's important to keep an open mind. Overall, I'm suggesting it may be best to just cut georgehifi some slack. While he may be clueless on how good current class D amps with traditional FETs have become, he oddly seems to have some good ideas on how to potentially make them even better. Love, Tim
that I completely fail to detect any of the sonic shortcomings that georgehifi claims exist on my amps due to traditional FET transistors, the switching frequency being too low and the filter used to remove this switching frequency being of poor quality.
That’s your opinion with your hearing, there are countless others that have the opposite opinion to you. The rest of your bs post is just flaming and has no relevance.
"
that I completely fail to detect any of the sonic shortcomings that georgehifi claims exist on my amps due to traditional FET transistors, the switching frequency being too low and the filter used to remove this switching frequency being of poor quality."
Hi mapman,
This quote from one of georgehifi's previous posts is actually my words from a post that has since been deleted by a moderator for some unknown reason. I was referring to georgehifi's frequent comments criticizing good class D amps, which I consider myself to be a user of, as all having sonic shortcomings due to using traditional slower FET transistors, the switching frequencies being too low and poor quality filters used to remove these signal carrier frequencies. My point being my total failure to detect any sonic shortcomings in any of my 3 good quality class D amps despite his persistent claims that these shortcomings exist.
Nevertheless, I believe the questions from your last post, directed at georgehifi, remain very relevant questions:
George what specific amp or amps are you referring to in regards to "sonic shortcomings"? Two or 3 examples will do if you could.
Also what amp or amps specifically are you comparing with to reach that conclusion? What were the shortcomings of those?
Are you comparing apples/apples in terms of cost?
What are your reference recordings used to make the assessment?
Just to be clear I’m asking what you have specifically heard, not what you deduce from other sources.
Being a technical guy, I’m sure you can appreciate the value of being specific and not making generalized statements based on a limited sample. Georgehifi has consistently refused to answer all questions about his claims of sonic shortcomings in recent class D amps in general. He's failed to respond to requests to elaborate and be more specific on his claims of sonic shortcomings from myself, several others and now from yourself. Based on georgehifi's numerous responding posts on many class D threads, it's fairly obvious to me that he has little to no experience actually listening to good quality class D amps. I say this not only because his descriptions of what these claimed sonic shortcomings sound like are very vague but also on his obvious inability, and often just refusals to respond to requests, to be more specific in his descriptions of what these sonic shortcomings actually sound like. Because of the above, the complete lack of supporting evidence of his claims from any source and my and others' complete failure to detect these sonic shortcomings in any of our good quality class D amps, I've reached the baffling conclusion that he's fabricated his claims of sonic shortcomings for some unknown reason. Although he frequently states he'll buy class D amps once they are perfected, I now consider this an attempt to disguise his true prejudices against class D and possible ulterior motives for his statements, unsupported theories and comments.
Like I said, it’s owners like you that will be the first to jump into this new GaN technology once you realize what you’ve gotten used and missing out on.
With my Merrill Audio Veritas class d amps I do not hear any musical shortcomings as some here/hear have speculated...That is of course within the confounds of my system and my musical priorities..The Veritas amps can produce that magical quality of live music being sorted out in front of me with none of that sugar coating of sound that just gets in the way of any high quality recording. I can't imagine someone ever thinking these amps are subpar in any possible way..unless you like that sort of glossed over sugary sound presentation.. Are they a perfect amp for all people? No...But such a beast does not exist.. I have talked with Merrill and he assures me the new proprietary Element amps of his design are a huge step up from the Veritas amps in every way that is musically important to me. If that be the case...they will be very special indeed. GaN technology just might bring that promised mythical beast of a near perfect amp within reach of the audiophile community at large..we shall see.I have my eyes set on the 114's when they become available late spring/early summer this year... 8)
I was hoping the link you included in your post was finally some, ANY, information supporting your false claims about class D sonic shortcomings. But no, you're just continuing your evasion and refusal to answer questions meant to clarify exactly what these dubious sonic shortcomings actually sound like. It has become increasingly obvious that you have little to no experience listening to good quality class D amps and that the reason actual owners and users of good quality class D amps are unable to discern these supposed shortcomings is because they do not exist. Please understand that without a shred of supporting evidence, your inability/refusal to answer ANY clarifying questions and the absolute inability of users to perceive even a hint of your imaginary shortcomings, your claims have lost all credibility just as you are losing yours. On the positive side, those GaN transistors seem interesting.
At some point, folks need to be less critical of others with whom they disagree. Piling on with repeated posts is a form of abuse towards a member that the moderators regularly condemn and remedy by removing posts.
George has stated he has heard a variety of class D designs in a variety of threads. Maybe doing a small amount of research before posting questions about his not having done so is in order.
I’m a massive fan of Class D/T etc.. (hence me starting the thread), but I support georgehifi’s comments 100%
I believe without doubt that Class D will eventually equal/surpass the very best Tube & Class A. Maybe next year, maybe 10 years?? It’s only a matter of time.
..but I’m yet to hear a Class D amp that didn’t display some of the artefacts georegehifi describes.
To my ear, Class D has real clarity & tight clear bass. It can have a tube/SET like bloom, which I really like. BUT, it can sound processed & lack soul.
I owned a not inexpensive Devialet 250. I thought it was amazing at first, but there was always a certain something I couldn’t put my finger on... Then I heard the Devialet Phantom. Very “impressive” (how does that little ball produce so much sound??...), but without doubt the most offensive processed sound I’ve ever heard. I went home to my Pro 250 & I could hear it. Only slightly compared to the Phantom, but it was there. It was finished. I got rid quickly.
So I’m still searching to find a Class D amp that gives me that clean, clear, tubelike presentation, but without the processed treble.
I and many other class D fans, as well as many professional audio reviewers,. consider the Merrill Audio Veritas monoblocks one of the finest amps utilizing current class D technology. The fact that you cannot detect any shortcomings in their excellent sonic performance is surprising to exactly nobody, perhaps not even to georgehifi. I've been using a pair of D-Sonic M3-600-M monoblocks, that I and others would likely classify as good quality that are priced at about 20%of the Veritas, in my system for over 3 yrs now and even I have also completely failed to detect any sonic shortcomings that georgehifi has so vaguely described and insists exist. Georgehifi has been spewing class D disinformation for years now on multiple audio forums without any supporting research results, information or even anecdotal examples. It's highly suspected that he has very little to no experience listening to good class D amps, since it's the only explanation for his obviously ignorant theories, statements and comments concerning class D. Fortunately, clueless anti-class D propaganda has zero affect on those of us who have experienced the truth. I agree that the newer and faster GaN transistors may allow class D performance to get even better. Interesting times for audio. Enjoy, Tim
Georgehifi has been spewing class D disinformation for years
This deserves a retort, just for your information, I was the one who showed and posted all about this new GaN technology with it’s higher switching frequency and better dead time into this forum years ago. "YOU CAN"T HANDLE THE TRUTH"
I agree that the newer and faster GaN transistors may allow class D performance to get even better. Interesting times for audio.
Hedging your bets there sunshine with that last statement, spoken like a true owner, seller or manufacture of present day Class-D technology, bet your one of the first to jump ship.
Certain users continue to pile on other members by essentially reposting attacks. This really needs to stop. If folks don’t stop engaging in this behavior, then the moderators will step in and delete the entire thread. I don’t really think the majority wants that to happen.
Members need only make their point once in a single post. Continually making the same critical point against a member in follow-on posts is abusive.
And to be clear, I’m the member who reported to the moderators that certain posts should be removed as being abusive to other members.
George has stated he has heard a variety of class D designs in a variety of threads.
Funny thing that George can cut and paste the same web links over and over again, but has trouble doing the same for his personal opinions.
I daresay George has spent more energy in all of Audiogon refuting people who like class D.
Since he spends so much time and effort, let him make his case for his personal experiences in each thread too. It is not up to us to chase down his previous posts to help him make his claims.
Again with insults just after celander told everyone to cut out the personal attacks. If I have posted up links that are not correct in what's presented, please counter them with the corrected link/s that prove them wrong, instead of just attacking someone personally.
Hello singintheblues I dont have too many experience with different amps and Im still burning my Nord One UP NC500DM class D stereo amp, but to my ears and, in my I understand very resolving system, it betters my previous 300B class A Line Magnetic LM-508 integrated (used as a power amp) in every field (dynamics, 3D sound, black background, bass, instrument separation, tone, texture, etc), even with upgraded tubes. The LM-508IA is a very musical amp an a very rewarded one among audiophiles and it cost more than twice the Nord, weights 6 times the Nord, produces a LOT more heat and consumes more power. The highs of the Nord with the Sparkos Op Amps are so precise and no harsh at all that music is rendered with a beauty I can not explain. And to finish my post, the Nord has the Rev C boards an not fully burned yet. The Rev D are on their way. I cant wait to hear it with the new boards!
I’m fed up with the relentless attacks against George being posted on this thread. If members don’t stop the nonsense, then I hope the moderators shut down this thread.
I’m fed up with the relentless attacks against George being posted on
this thread. If members don’t stop the nonsense, then I hope the
moderators shut down this thread.
The attacks aren't personal. They are based on his behavior. He really has a problem with anyone enjoying current Class D and every thread that is about enjoying current affordable Class D George inserts himself into them in ways that are the opposite of constructive. So, sorry you are fed up, but a lot of us are also fed up. Delete the thread. I'll start one called "I like inexpensive Class D amps" and George will be right there calling my amps "junkers" and telling me my hearing is not good enough.
In THIS PARTICULAR THREAD, I see nothing but constructive input on George’s part. It’s the reactionary anti-George commentary that is front and center.
You should mark George's entire presence in Audiogon regarding Class D for review.
We've been absolutely patient, open minded and requesting of more information. He's routinely obliquely insulted, and disparaged a number of members, while failing overall to make his points on their merits, and here you are suggesting we read all his threads to get him to talk about personal experiences and preferences.
Give it up Eric, as I said if you have a problem with what I post, eg: like in the way of links of proof of $100 Class-D modules in $10,000> amps ect, then combat them with opposing links if you can! Not go for the personal attack.
-10 George and Calendar for being less than truthful, mischaracterizing other Audiogon members, including myself and projecting.
I've never attacked you personally, show me a place where I have, George?
Nor have I thought your war of web links was constructive or useful.
In fact, George, you personally asked me to let those who enjoy their audio enjoy it and let them be at peace, while you attack everyone who likes Class D as having poor hearing and owning "junkers."
So, George, why haven't you let those who enjoy Class D as it is today, enjoy it? Wasn't this what you asked me to do? And are you not pretty much telling us we must not have very good hearing if we like it?
I'm describing your behavior, by the way. That's not a personal attack. That's a summary.
I can not only handle the truth, I respect it and have a habit of speaking it. Can you claim the same? It is true that you did post about the newer GaN technology a while ago and their potential beneficial potential for audio amps and I found it very interesting and promising. Thank you. I have no issues with you touting the potential benefits of faster switching GaN transistors that would result in reduced dead-time and reduced distortion. GaN transistor technology is a few years old and their potential for improved solid-state audio amp performance are well understood and mainly agreed upon. My main issue with you concerns your claim/theory that current class D carrier frequencies are too low and result in sonic shortcomings in the audible range. Unlike GaN technology, the potential benefits of higher switching frequencies for improved class D amp performance have not been researched and, therefore, are not well understood or agreed upon. The truth is that It also has never been proven that current level switching frequencies are too low and result in any sonic shortcomings in the audible range. Yet, you seem to believe it's just a matter of opinion as to whether these sonic shortcomings exist in the audible range. I believe this has yet to be decided empirically. My take on this issue is a bit involved but not really complex. My reasoning is that,if your theory of sonic shortcomings in the audible range are someday proven to be false, then that nicely explains why I and many other users of good class D amps have failed to hear them since they don't exist. If your theory of sonic shortcomings in the audible range are someday proven to be true, however, then that would verify their existence but present a whole new issue of why I and many other users of good class D amps are unable to discern these now proven sonic shortcomings. I.can state with absolute certainty that I cannot discern any sonic shortcomings on any of my 3 good quality class D amps that all have switching frequencies in the 600 KHz range. If your theory is someday proven to be true and sonic shortcomings actually do exist in the audible range due to the switchng frequency being too low, I'd be very concerned about why I wasn't able to discern these now proven sonic shortcomings. I'm now 60 and have never considered myself to be a 'golden ears', But I believe I still have good hearing, I'm able to discern the differences between various power cords and interconnect cables I've compared on my class D amps and think I'd be able to hear any sonic shortcomings on my system if they existed. After I initially read of your theory concerning the switching frequencies on class D amps being too low and being audible, I was a bit alarmed because I could not hear any sonic anomalies on my class D system. So, I spent most of a Saturday listening to my system trying to detect any sonic shortcomings in the midrange and treble but failed to identify even a hint of any sonic anomalies. Ultimately, I had no choice but to conclude that no sonic shortcomings existed on my class D system. The only other possible conclusion is that I, for some unknown reason, am incapable of perceiving these sonic shortcomings. But I consider this a bit of stretch with the current lack of research supporting this premise.
So, I'm going with the conclusion that these supposed class D sonic shortcomings don't actually exist until proven otherwise.
I threw my hat into the ring here quite a few pages back suggesting initially that the Anthem M1 be considered for audition as my personal experience is that I like far better than my very well received Parasound A51 Halo, which of course is Class A/AB depending on the output level.
However as with so many other forums online in various other areas of interest, they often degrade into nasty commentary. I blame the lack of face to face interaction as I don't believe people would speak this way to someone's face in person (there is too much risk of getting punched).
Anyway, I keep it simple, I stop following any threads I don't find are productive any longer and I guess its time to do just that.
George has trouble making the case that a particular technical issue (i.e. dead time) results in a particular sonic aberration common to many Class D amplifiers.
As I may have mentioned, I’ve had a number of audiophiles in my home (when it was better acoustically than now) and no one said "wow, that’s a Class D amp!"
They may not have liked the sound stage, since I make pretty laid back speakers, but not a single person has ever stopped and gone "Woah, that dead time man, how can you stand it?" In my bedroom I use an NAD 3020 D and it is pretty fine sounding. No switching artifacts can be discerned. If you only believe in reviews, fine, go read them and tell me which published reviewer says they can tell its class D.
In fact, once at the end of watching a movie did of watching a movie did my invitees say "by the way, where are your amps?" All my fronts were Class D with a Parasound driving the Surrounds. The sound was seamless. No one heard a difference in noise, distortion or coloration. Room EQ was applied to the sub and center only.
From a practical experience, and listening with others, I am fairly confident of my experience. Class D is dandy. I also have no particular reason to push Class D to those who like tubes, mega Class A or SETs. Enjoy what you want to listen to, with friends and enjoy it. What I have problems with are heroic efforts being made to make people doubt their own experience with Class D. Damn, I wish I could afford a pair of CJ Premiere 12s, because those beat everything ever.
Like Tim, I look forward to new technology. Since I consider Class D being capable of exceptional performance when matched well, I can only hope modern tech makes it even better. But 300 links to discussions about distortion profiles in the 100kHz range are not going to convince me something is wrong with my hearing.
Fellows, this has been a very interesting thread and I even understand a lot of it, but I am reminded of two things: 1) Two ( or more ) cooks can start out to make the same meal and come up with very different products. It doesn't mean that their food source was bad, but that they cook differently. Of course, if you start out with bad food, then it is harder to achieve a good meal. Some cooks can do it, while others can not. 2) As more cooks become aware of a new food source, some one will improve on the way that source is used. In the electronics word, this improvement can happen rapidly. I hope no one makes fun of this analogy, as I think it is a good one, but improvement in the new Class D technology seems to be coming fast. FYI look at the latest issue of THE ABSOLUTE SOUND's cover story on the new and cheap NAD C328 Hybrid. I predict that two years from now, most new under $1K amps will be Class D and many under $3K amps, as well.
The Class-D is just going to be a money spinner for him, he buys the
modules does a small mod so it can be said to be better, throws in in a
box, and there’s his beer money.
@georgehifi Just for the record, this statement of yours from the beginning of this thread is entirely false. Our design is from the ground up entirely our own so we don't use anyone's modules. We have a patent pending on how we eliminate the need for dead time.
By eliminating dead time we can use much slower transistors than Gan devices and yet switch at the same speeds. Of course we can use Gan devices too.
BTW looking at the heatsinks in the SU-G30 above, that section is the
GaN amp, it may have higher than todays 600khz switching because it’s
using these heatsinks, as EPC said to me if left at 600khz there is no
need for any heat sinking on any of the GaN boards, so it maybe higher.
Heatsinks are required, even for Gan devices switching at lower speeds, regardless of what EPC allegedly said. The reason is that all output devices have a finite 'on' resistance which is exactly zero. It might be 0.05 ohms, but its not zero. This means that it will make some heat when full on and that heat builds up over time.
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