GaN-based Class D power amps

Please read the review of the Technics system:

http://www.theabsolutesound.com/articles/technics-r1-reference-system/?page=2

What it says is that the Technics amp is not a class D amp......it is a digital amp. IE....it takes only a digital signal and then converts the PCM stream to PWM to drive the switching output stage. The "analog" input on the Technics amp goes through a 24/192 A2D converter to change it to PCM so it can then get converted to PWM.

Of course, the switching output stage is the same as class D but the way it is driven is far different. The Tact amp was the first (I believe) to do this. Of course, its switching output stage does use GaNs, so should be included here. But, not many audiophiles want their precious "analog" signal turned into digital.

So, right now the only analog input class D amps are the Merrill and the AGD. I asked Nuprime on their forum on Audiocircle if they were planning to develop an amp using GaNs........and they said it was in R&D.......and that they thought they were way ahead of most others. They thought it would take 2-3 years before there are any standard off the shelf modules available.

What is really interesting is that Technics claims that using just one GaN per phase is really important.....rather than a bunch of parallel Mosfets like the earlier IcePower, etc. Certainly the dead time can be kept shorter if there is just one switch per phase. Other newer class D amps have just one mosfet per phase also.....like the IceEdge modules. They also have "continuous dead time compensation (CDC)".......maybe these are reasons why it sounds so good?......sort of simulating the "GaN effect"? Of course, using GaNs would reduce the dead time so much you probably would not need to compensate at all and probably have even better performance. I have been talking to IcePower USA.....trying to get them to get into the GaN thang.........looks like inexpensive class D GaN amps are not in the immediate future. Since everything you do changes the sound, we need lots and lots of manufacturers working on this....so we can have lots of variety and hopefully way cheaper prices......right now its a $15,000 entry fee to get into GaNs. To rich more most of us here.

There is that esoteric hard to find 12 volt car amp that uses them.....I am trying to get info on it....seems like it sells for around $1200 but info is scarce (no info on the manufacturers website). I am waiting from the manufacturer for into. I will let you know what I hear.

It is not clear whether the cheaper Technics is a digital amp or a class D amp.  I will use these terms because it is very clear.  A digital amp takes the analog signal and coverts it to PCM though an A2D converter and then converts it to PWM.  A class D amp takes an analog signal and converts it directly to PWM.  The only way I found out the larger Technics amp was a digital amp was to read the very clear review I linked to.  

Many would not want their analog signal (using their multi thousand $ DAC or phono stage) to go through an A2D converter).

George,  please use your sleuthing capabilities and find out for us if the Technics converts analog to digital first or not.    I just sent Technics an email asking them.  I also asked Technics if the SE-R1 is even sold in the US as it is not listed on the US portion of the website.  It is listed as sold in Japan.

I finally got a response from Soundigital and they said they are $800 and have warehouse stock in Florida.  You would have to contact a Soundigital dealer to buy it.  This amp uses 12 volt power and has rca inputs only.  Someone should buy it and mod the heck out of it.  Would be a fun project.....I am not volunteering.  

What it says is that the "output stage" is class D......it does not say how it is driven. Class D and Digital both use the same switching output stage. It is how it is driven that differentiates them (at least, to me). All the info on the SE-R1 says nothing about the 24/192 A2D converter used on the analog inputs. It is only stated in the review I posted. And Technics did not say it was wrong info. So, is there an A2D converter on the analog inputs of the cheaper Technics? We have yet to find out. If it has one....then it is a digital amp.

Hey nothing wrong with converting analog to digital. But, it is one more process and everything you do adds distortion. If it is done to the Nth degree then great. Do you think Panasonic would make the worlds most transparent A2D converter?  If you use normal op amps on the input of your A2D converter then you have loss.  You would want sonically superior discrete circuits, super sounding resistors, caps, state of the art power supplies, dual mono, etc.

Lots of class D and class A and class A/B amps are better than the old Merrill Veritas......not a current reference. Listen to the $8000 Nuprime Evolution amps......these might give the latest GaNs a run for the money for a lot less. Then there is the latest (just now being released) version of the DAC Megacherry amp ($6100)......I am sure there are others, as well. We need some GaN amps less than $15,000.........I bet within a year we will see some. By the way, DAC and Nuprime each have their own patents on class D and make there own stuff.....no stock modules from other companies. There is no reason why a GaN amp should be any more than $100 more than a mosfet based amp. So, in a few years, you will see $500 GaN amps......even kits. I think we will see a Nuprime GaN amp within a year (it is in development now).

The most exciting thing about GaNs (assuming they make Class D better) is that you will be seeing more and more integration in audio. Imagine a 2 or 3 channel GaN amp inside a speaker with digital input circuitry, electronic xovers and room eq. No more speaker cables, analog line cables, multiple power cords, racks, etc. You just have source and a couple of Ethernet cables going to your speakers with built in everything.....including GaN amps. We are talking super sound for the masses. The source box would have an A2D converter to convert your phono stage (or other analog source, if any) to digital to run to the speakers......very cool. Cannot wait.

George,

Measurements mean very little......you must listen, listen and listen some more.....for reality.  Of course, really bad measurements are usually detrimental......however, what constitutes bad measurements?  You would have to listen to determine that.

I think GaNs will make class D better (everything else being the same).  However, we are in the infancy of their use.  Every GaN and every mosfet based class D amp will sound different as everything you do makes a difference sonically.  We have years of perfecting yet to come.

These first GaN amps are just the tip of the iceberg.  We will see relatively inexpensive GaN amps that blow these expensive first offerings away......no doubt.

Cannot wait for Worldwidewholesales to finally tell us their comparisons of all these GaN and non GaN (mosfet) class D amps.

George,

If voodoo means listening to things and using the best sounding things then certainly I am a super voodoo lover.

Everything sounds different.  Most things that make a difference sonically cannot be measured.  I just did a listening test of three different female xlr input jacks (Neutik, Cardas and Furutech).  All three sounded different.  All three measure the same.  This is the same for solder, wire, capacitors, fuses, resistors, damping, shielding, power supplies, bypass caps, etc. etc.   All these things make the sound different and yet they all measure the same.  This is from my direct experience of over 40 years of listening tests.  This is why every single amp from every single manufacturer will always sound different.  Believe it or not!  It is not my belief.....it is my BE LIVE......for experience is the direct truth......you have to listen to know!

Yes, really bad measurements usually correlate to poor sound.  However, most all Class D amps measure fine (low distortion, high damping factor).  This is my point.  You were asking the person whether they were going to measure the amps (all Class D).  This is what I was responding to.  Almost all Class D amps measure pretty darn good.  The Ncore amps measure better than most but are now taking a sonic back seat to the new IceEdge modules that measure great, but not as great as Ncore.  Another words, the measurements have nothing to do with the sound in this case......in fact, the cheaper Ncore NC400 measures slightly better than the expensive NC1200 but everyone says the 1200 sounds better.

Some tube and solid state amps and some zero feedback amps measure poorly......and usually this has a sonic result.  However, even some not so great measuring amps (Dartzeel and DAgostino, for instance) have a reputation for great sound in many ways. 

The new Relentless amp from Dan does away with the not so great measurements.  He uses over one hundred output devices to get low output impedance and super matches the front end so he can achieve low distortion numbers without feedback.  I am sure it sounds outrageous.....at a quarter of a million dollars, it should.  Dan makes his own output binding posts out of big hunks of brass......brass?!?!?!?!  Brass is very sonically lossy.  Why not Tellurium copper, or pure copper or PCOCC copper or silver or whatever.....but brass?  You pay $250,000 for amps and they have veiled output connectors.....yikes!  However, even the input connectors are $5 brass Neutrik connectors.  How much better would the amp sound with my binding post bypass system and some better sounding xlr input jacks?.......noticeably!.....and it would not measure any different.

All the tweaks and mods I have done to the IceEdge module do not make it measure any different......but the aural distortion has gone down tons.  You must listen.  Measurements can tell you very little of the actual sound.  Two amps that measure the same can sound worlds different.....so the measurements have no correlation to the sound.......they don't tell you how it sounds! 

Just changing the fuse, footers, shelving and power cord on an amp can give incredibly different sound.....none of which shows up on a distortion test.  This is just the beginning....there are tons of things one can do to lower the aural distortion in an amp that have nothing to do with measurements.....this is how it always was and always will be. 

Measurements are fine.  It is good to have good measurements (I certainly prefer better measurements)......but it does not tell you how it sounds.

You cannot read the distortion measurements posted on some Stereophile review and know how an amp will sound.  All amps with decent specs will sound different.  You could have an amp with really high damping factor and it sounds not so great in the bass.  You could have an amp with really wide bandwidth and the highs are not worth writing home about.  Every single thing in an amp will add its sound.  One super bad resistor or whatever and BAM!.....there goes the transparency.  Here is an interesting fact.  Heatsinks ring.....yup.  If you take your fingernail and scape it across your heatsinks and if they ring then you are adding that sound to the amp.  Many people have tried damping their heatsinks on my suggestion and all of them are amazed at the sonic benefit......less "transistor sound".....he he....or should we say less "ringing heatsink sound".  Again.....not measureable.....but certainly audible.

I am not against measurements.  They can show you if you have a serious problem.......and some distortion artifacts (predominance of even or odd order, for instance) can be audible.  But obsessing about measurements?  Not in this house!  I want goosebumps.......I don't listen to a distortion meter!

And what have you to say? Come on, you just like to be right and argue and have the last word. I try to inform. I think my post is very informative. I think it will help people. There is probably someone right now damping their heatsinks and getting better sound.  Will your post help people?

How can we know how it compares if the "review" has no comparisons?....no mention of what amp he replaced or what other amps he has heard in his system. All we know is that his sound has improved. Maybe a $2000 amp from another company would also improve his sound.

It seems that some audiophiles are very "delicate" people. They don’t want to upset anyone by saying anything negative about some product. I mean, this is all very, very serious, we don’t want to make anyone "feel bad".....do we? Are we really this wimpy?!? If you really care for people then you want them to know all the information they can get so they can make the best purchases. If they bought yesterdays toy and you tell them it is not todays toy.....well that is just the way it is (or at least what you hear, in the here and now). There has never been a product that has remained state of the art......except maybe the Ionovac tweeter. Reviews without comparisons are worthless!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

The $8000 a pair mono blocks from Nuprime would be a nice comparison......their latest generation of patented Class D with 700K switching and all discrete front end with 1meg input impedance.......for 36% of the price of the Merrill.  He could have borrowed them from a dealer and we would know if these "GaN" amps are really better.....and if they are better, is it worth the money difference?

So correct, I read it real fast and assumed he meant he had the new amps since maybe January of this year. However, this review is still not helpful as the Veritas is nothing more than a stock Ncore module and has been beaten by many new cheaper amps (class D and class A/B....do some research). There are already at least 3 other reviews comparing the Veritas to the Element 116. Nothing new here and still no comparisons against other brands.

How are we going to know anything about these new amps if all we get is reviews of them versus old outdated Merrill amps.

You can borrow or buy with 30 day return many amps.  There is no reason to just buy the latest almost twice as expensive product from the same manufacturer when things are changing so fast.  There are so many possibilities.  Another possible really good class D amp is the latest one form DAC (Cherry amps).  They have a new Megachino 2 that has 150K bandwidth and linear supply, DC coupled with patented technology.....his very latest one just now released.  Basic stereo version is $6100.  You could buy this amp, the $8000 Nuprimes and compare to your Element 116s (that you borrowed or have the ability to return)........now this would be interesting.  Are we just lazy?  Don't you really want to know if there is anything less than $22,000 that might be better?

George,

My "cause" is great sound for everyone.  I love audio and I love it evolving.  Thank you for continuing to post my site.  Every time you do, I get emails from people who want my amp.  You are my shill!  People interested in $22,000 amps are not interested in $2000 amps.  I don't expect my highly modified dual mono fully tweaked IceEdge amps to compete at that level.,,,,,but who knows?!?

I am really excited about the possibilities of class D....whether using "dead time compensation" with mosfets, getting rid of dead time via patents, or GaN.  I want to know how these new GaN amps perform related to what is out there.  Reviews of old Ncore versus GaN do not let anyone know what is possible. Yes, I want reviews versus class A and class A/B as well.

We had a guy here who says he has 6 class D amps including 2 GaNs and was going to listen on 6 systems and let us know.....then he wimps out and says "people want to argue here, so I am not going to tell you anything". What he did say was: mosfet amps sound great or not so good and that GaN amps sound great or not so good.  Don't you want to know what he hears?  I sure do.  Information that could illuminate the situation.

As far as looking around, here is one that you missed.....class A/B mono blocks for $5000 that trounce the $12,000 Veritas mono blocks.

http://www.audiophilia.com/reviews/2018/10/13/audio-by-van-alstine-dva-set-600-mono-block-amplifier

George

Yes, I am panicking.....having a panic attack right now....he he.  Lighten up!!!!  There are no GaN amps under $15K right now that anyone wants and it will be some time before there are any at 2K.  Why would I panic?  My amp will sell if it sounds good for the money and not sell well if it does not.  This has nothing to do with GaNs or your opinion and you know it! I don't need my amp to sell to live.  Nor does Ralph need to sell his upcoming class D amps to live. 

In fact, I have been in contact with IcePower and trying to get them to play with GaNs.  I am the one that asked Nuprime on their Audiocircle forum if they were experimenting with GaNs.  I am PRO GaN!!!!!!!!!!!!!!

check out my post on the below forum and Nuprime reply.

https://www.audiocircle.com/index.php?topic=158342.40

George, you can be so negative.  This is not a battle of minds or wills.  This is a game.  Enjoy the audio game.  Make helpful comments and supportive comments.  But to take it so seriously......not a healthy thing!

Aolmrd,

Did you read the review on the above link about the Van Alstine amps that creamed the Veritas?  Did you also notice in that review a link to a review of the $2000 in black/$2200 in silver Van Alstine stereo amp that also creamed the Veritas?  The $12,000 Veritas is not a reference amp if a $2200 class A/B amp creams it.  A person who has borrowed the $22,000 Merrill 116s should really get a pair of the mono Van Alstine amps ($5000) and compare.....don't you think?  If they both cream the Veritas (according to the reviews) then it could be a fun shoot out.  This is what I am talking about.....actual A/Bs versus real stuff.....not just the manufacturers old stuff that cost almost half as much.  I would hope any manufacturer that makes an amp for twice as much as the old one would sound better.....if it did not they would not be in business long.  But what really matters is how does the new technology compare to the many other amps out there.  Looks like we are in for a long ride as the comparisons are just not coming in.

The Van Alstine mono blocks are pure balanced bridged amps.  They have xlr inputs.  There is an option to have rca jacks as well, but then it has a single ended to balanced circuit inside to then run balanced to the amps.  The amps are fully balanced.  As far as junk output jacks.....so what?  What matters, is the sound.  Now, if I tweaked the Van Alstine amps I would use my binding post bypass system and other tweaks for even better sound.  Are we so cynical that we think the reviewer was paid to say this and actually prefers his Merrill?  How does he get clout when reviewing a no name amp that looks like a black box?   Looks pretty genuine to me.  Buy, you never know.  But two reviewers in the same magazine using different systems are saying the same thing.  Pretty convincing.

Most reviews are worthless, unless they have mucho comparisons of the latest same money gear and show the gear being used. We are all in the dark. We are kept ignorant unless we A/B in our homes. Let’s say you wanted to spend $20,000 on an amp. So you read online for 2 weeks straight on every site and decide the 10 best possibilities. So, you arrange with dealers and manufacturers to buy all these amps with 30 day money back guarantee. So, you put out $200,000 of your own money. Of course, this all depends on them arriving at the same time and every dealer and manufacturer being OK. Of course, you do not tell the manufacturers or dealers what you are doing....or very few would go along with this. You listen every weekend with your buddies to all the amps and then keep the best sounding one for your system and send back the rest to get your money back. Once you have received all your money back you go onto a forum like this one and tell everyone what you discovered. Now, everyone who reads this will have an idea of what all those amps sound like and at least not be in the dark. Of course, once you posted your results then you would be person non gatis to some of those dealers and manufacturers. Of course, this is why this would never happen in a magazine. If they did this the losers would never advertise again and the magazine would go under.

You must realize that most reviewers do not get paid and their only perk is to get gear at 50% off. They don’t want to bad mouth an older product or they could cut off that manufacturer from every sending them another product. Check out this review of the Merrill 118: http://www.enjoythemusic.com/superioraudio/equipment/1018/Merrill_Audio_Element_118_Monoblock_Amplif...

He never mentions his "reference amps" and at the bottom he only give is 4 notes on several catagories (so he knows there is more to be gotten there).....but he does not tell us what amps do those qualities better. So, we can gleam that it is a great amp....but how good. There are no comparisons at all that have any meaning. Typical review......we are left in the dark, once again.

These reviewers are not bad people....they are not on a mission to get all your money and send you to hell. They are just people, like you and me.....but, because there is money and survival that goes along with this, they withhold information.

If you want to buy a $30,000 car you read online for a few weeks and then go test drive all the cars you want and then buy the one you want. Don’t you think it should be the same with audio? Where can you test drive audio gear.................................only in your home. And it is not easy, unfortunately.

By the way, have you ever noticed that car and camera gear, etc. reviews do not hold back any info. They tell you which ones they like and exactly the differences (measured and subjectively). It’s only subjective audio reviews that tend to be secretive. There are no measurements to tell you how they perform, so we must keep it all secret so you keep buying our magazines......not exactly evil....but sad. The original Audio Critic magazine bought all the audiophile preamps they could and did a complete review of all of them at the same time. Of course, back in 1979 or whenever that was, there were not that many products. What is really interesting is not just that no one ever did anything like that again, but that the owner of the magazine started to push his own speaker and then started to screw his readers. Then he became an "objective" audiophile and went 180 degrees......just a little old drama for you.