GaN-based Class D power amps


The use of GaN-based power transistor tech is now emerging for Class D audio power amplifiers. Seems appropriate to devote a forum thread to this topic. At least 3 companies have commercial class D amps in their books:

Merrill Audio, with their model Element 118 ($36k per monoblock, 400 W into 8 ohms, 800W into 4 ohms), Element 116 ($22k per monoblock, 300 W into 8 ohms, 600W into 4 ohms) and Element 114 (coming soon). 
https://merrillaudio.net

Review of Element 118 at this link:
http://www.enjoythemusic.com/superioraudio/equipment/1018/Merrill_Audio_Element_118_Monoblock_Amplif...

ADG Productions, with their Vivace Class D amp ($15k per monoblock pair, 100W into 4 ohms). (The designer emailed me indicating he has another product in the pipeline.)
http://agdproduction.com
Review of the Vivace Class D moniblocks at this link (warning: link might not work (1/11/2019)):
https://positive-feedback.com/reviews/hardware-reviews/agd-production-vivace-gantube-monoblock-ampli...

Technics SE-R1 Class D stereo amp ($17k per stereo amp, 150WPC into 8 ohms, 300WPC into 4 ohms) 
https://www.technics.com/us/products/r1/se-r1.html
Preliminary review of the Technics SE-R1 at this link:
https://www.stereophile.com/content/technics-se-r1-digital-amplifier
Technics also has a lower priced GaN-based class D integrated amp in their catalog:
https://www.technics.com/us/products/grand-class/stereo-integrated-amplifier-su-g700.html

Anyone listened to or own any of these amps?


PreviewAg insider logo xs@2xcelander
I believe the Merrill’s are priced per pair, not per monoblock, as posted. Enjoy ! MrD.
Still way too expensive; when they hit $5000 for a pair of monoblocks I will take notice.
MD, +1 for the price correction.

Merrill Audio, with their model Element 118 ($36k per monoblock pair, 400 W into 8 ohms, 800W into 4 ohms), Element 116 ($22k per monoblock pair, 300 W into 8 ohms, 600W into 4 ohms) and Element 114 (coming soon).
https://merrillaudio.net

I suggested elsewhere that the AGD Productions Vivace might be a bargain at $15k per monoblock pair. Clearly, the Merrill Audio products are quite competitive given the W per $.
I just wanted to pop in and say I too look forward to first hand listening experiences, as well as direct comparisons with other Class D and other types of amps.

Best,
E
The use of GaN-based power transistor tech is now emerging for Class D audio power amplifiers. Seems appropriate to devote a forum thread to this topic.
+1 Glad someone else did this.
https://images-na.ssl-images-amazon.com/images/I/51-G3tQVdfL._SX425_.jpg

Cheers George
The Technic SU-G700 listed in my OP appears to lack the GaN FET driver stage of the other GaN-based Technics products. Here is a GaN-based Technics server/integrated amp that includes a GaN FET driver stage:
https://www.technics.com/us/products/grand-class-g30/network-audio-amplifier-su-g30.html
A review is available at this link:
https://hometheaterhifi.com/reviews/amplifier/integrated-amplifiers/technics-su-g30-network-audio-am...


This is a newer technology, some are very using  with mosfets , there are a a lot of good digital out there . In my Amp Danish Gato Audio they use Pascal modules, which BTW Jeff Roland uses and make custom analog input,output sections .
That meet or beat most  Class AB amps out there. Times are changing very fast.
https://epc-co.com/epc/GalliumNitride/WhatisGaN.aspx

Just a clarification... There is no GaN-based technology in the Pascal modules used in Rowland amps.


Regards, Guido

 

If these new Class D amp have as little parts inside as the other types of Class D amps, I would  spend my money elsewhere.
There is no GaN-based technology in the Pascal modules used in Rowland amps.
No there isn’t.
Some of Rowland’s that use Pascal modules, started of from Sangway Class-D modules from China.
As can be seen here in the Rowland Contiuum 2, and the same module in these subwoofer plate amps.

Rowland Continuum 2
http://www.theaudiobeat.com/equipment/pics/jeff_rowland_continuum_2_large_inside.jpg

Marani plate amp (upside down compared the above Rowland)
http://www.marani-proaudio.com/resizer/resize.php?url=public/PDA800P.png&size=1000x250
And in these also
http://www.marani-proaudio.com/resizer/picscache/800x600/73a9fee129dc4d9ca1c8b7ff5567931c.png
http://www.marani-proaudio.com/dettprodotti-PDA800P/95_60/eng/

Sangway Factory tour China.
https://www.youtube.com/watch?v=EZCxCg-QWDQ

Cheers George
Not saying Guido all Rowland's have Chinese Class-D modules in them, I've just found the Continuum 2 amp so far.
I've yet to go looking for other internal shots of Rowland models to see if they are, or are their own modules.

Cheers George     

George, please do not contaminate this perfectly good thread dedicated to GaN technology with your irrelevant paperholic conspiracy theories... I invite you to move post material that have nothing to do with GaN to one of the other class D threads.... Best would be the Future Of Amplification thread. 


Regards, G.



G.,
Despite owning several JR components I do think George is trying to make a good point. With so few parts, what justifies the high cost of some Class D amplifiers, including the JR Continuum S2? I understand R&D, overhead, and profit, but more and more the cost of Audio is getting crazy.
I hope reports surface from CES 2019 regarding new products having this GaN-FET power transistor tech. 
@ricred1 Just my opinion but HEA is such a niche market with fewer and fewer buyers each year, companies have to keep charging more for they sell less. Again just my thoughts.
Jeff Rowland gear is always very expensive. I guess that is part of his design package. 
rsf507, 
I agree with you about HEA being a niche market. The question it seems more manufacturers would be asking is how to expand their market. I submit the ever increasing cost is a significant factor that prevents many from being involved with HEA.
IF you can undercut very expensive high end gear with not quite so expensive other gear that delivers sound people think competes or maybe even sounds better and make a better profit at it then that is a good thing for all except sellers of very expensive high end gear.

Not to mention Class D is most efficient and runs cooler so you save on power bills.
contaminate
No, sorry Guido you Audioman mentioned Rowland and Pascal. Not me.
I took it back one stage further where the Class-D modules really come from, Sanway China.
It’s perfectly valid to show what’s going on in this industry, your upset because your very pro Rowland, I understand and I did in the very next post say that the Continuum was the only model, so far, as I’ve not seen inside others, YET

Jeff Rowland gear is always very expensive. I guess that is part of his design package.
That’s an expensive box to say the least.
Exactly the point I was making, those exact same Sanway boards were $100 each on Alibaba in lots of 10, so god knows what Pascal and Rowland were getting them for, and the Continuum was some $10k without extras.

Cheers George


georgehifi4,762 posts
01-14-2019 2:51pm


http://www.ti.com/power-management/gallium-nitride/overview.html 

Here we go hopefully, one of the majors have got the rights to make it, watch Class-D take off now, and finally compete with the best of Linear amps in the mids and highs and beat it in the bass as it always did. 

Cheers George 

☝🏻☝🏻 One of George’s posts from another thread that is relevant here. 
There was a car audio amp shootout done about an year or so back and the only Class D amp to make the top tier list was a GaN based amp, Soundigital GaN 300.2d .
Here is the link.

https://issuu.com/diogoianaconi/docs/amplifier_shootout


Yep looks like GaN technology has infiltrated into car audio also and beat the competitors, the SoundDigital SD300.2
https://ibb.co/80x8L1C

Matt Hall, a very experienced sound quality competitor and audiophile, has done an amazing test with numerous high end amplifiers from different brands.

There were a total of 18 listeners, all unaffiliated with any audio equipment manufacturer.

We are proud to announce that the GAN made it to TIER 1, which was reserved only for the highest quality amplifiers, the ones that can be really used for Reference Level listening.

This is a direct quote from Matt’s review: "Describing how dimensionally accurate, transparent, and dynamic this lightweight amplifier is with profound adjectives seems disingenuous, but I assure you, I’m no charlatan. This amplifier is legit!"

To read the complete review, please click here: http://issuu.com/diogoianaconi/docs/amplifier_shootout

Soon we will be releasing information on the new GAN amplifiers. We will have a 2-channel and 4-channel version!

Cheers George
I would think the  Merrill Audio, with their model Element 118 ($36k per monoblock, 400 W into 8 ohms, 800W into 4 ohms), at the asking price should sound extraordinary good but for 2000 GBP you can own the remarkable sounding Nord Acoustics with the new REV D boards plus the added extra of choosing your choice of op amps depending on what sound suits your personal tastes or system better its called op amp rolling.
The sound of the Nord Acoustic amps is by far the best sounding amplifiers i have heard period and no i have no connection to Nord Acoustics they sell direct to the public.
With so few parts, what justifies the high cost of some Class D amplifiers, including the JR Continuum S2? I understand R&D, overhead, and profit, but more and more the cost of Audio is getting crazy.
GaN transistors are still a bit more expensive. Class D amps have to meet RFI regulations and to certify that sort of thing (for example, to obtain the CE mark so it can be imported into Europe) can cost quite a lot- $15K for starters. So while the actual parts cost is low, there is a bit of overhead that does not exist for traditional amplifiers.
To my knowledge, the Nord Acoustics Class D products do not presently include GaN-FET transistors, which is the topic of this thread. There is another thread that specifically addresses Nord Class D products, to which I ask folks to post Nord-specific posts.

https://forum.audiogon.com/discussions/which-class-d-amplifier-ps-audio-ghent-nord-merrill-or-other
Ralph, is that $15k price tag for the CE mark a flat certification fee, or a fee cost applied to each amp?
Red Dragon makes it’s S-500 amp using the same Pascal/Sangway pro2 modules and sells them world wide for just $1k not $10k!!!

http://www.6moons.com/audioreviews2/reddragon/3.html

https://www.reddragonaudio.com/products/s500?variant=969867425

Quote:
"Rowland integrated Continuum S2. Red Dragon’s S500 beats with the same heart in a less high-end chassis"

Cheers George
Correct me if I’m wrong, but I don’t think Jeff Rowland nor Red Dragon include GaN-FET transistor tech, which is the topic of this thread. Please keep this thread clean and relevant. 

Cool it.
I’m making a comparison to what you said, re the $15k price tag for the CE mark and how this can;t be right, because those two use the same modules, just the chassis are different

Celander is correct,



* Rowland does not make use of GaN technology in any of its products.


* The Rowland Continuum S2 integrated sports original Pascal M-Pro2 modules. Rowland does not make use of counterfits.


G.


* Rowland does not make use of GaN technology in any of its products.
In don't think anyone said they did???

* The Rowland Continuum S2 integrated sports original Pascal M-Pro2 modules. Rowland does not make use of counterfits.
Seems your insinuating the $1k Red Dragon amp uses counterfeit Pascal/Sangway modules? 

George, please have the decency, or at least the common sense not to put words in my mouth.


I am not in the habit of insinuating. I make my statements deliberately narrowly scoped. I speak only about what I know, and make no speculations about products and/or companies with which I have little familiarity. I urge you to do the same.


Please give this entire matter a rest... Let's try to stay on topic, folks.


G.




* The Rowland Continuum S2 integrated sports original Pascal M-Pro2 modules. Rowland does not make use of counterfits.

Well sunshine, don’t "insinuate" that the Class-D module in the $10k Continuum 2 is not the same as the one in the $1k Red Dragon, and that it’s counterfeit.

http://www.6moons.com/audioreviews2/reddragon/3.html
Quote:
"Rowland integrated Continuum S2. Red Dragon’s S500 beats with the same heart in a less high-end chassis"
Back on topic, it would be good to hear from users of the new Merrill GAN amps and their comparisons. Our reference class D being the Mola Mola Kaluga’s at £9,950 per mono pair, expensive enough but much better than other class D amps we have tried and they compare very favourably with some class A amps costing £50k. The new Merrill’s at more than twice the price ought to be better, that would make them very interesting if price is no barrier. Compatibility with a top dac is a concern with the Merrills, it doesn’t look like Merrill has a top flight dac on offer, if I’m not mistaken. The Mola Mola Makua dac works so well with their amps.
Post removed 
Ralph, is that $15k price tag for the CE mark a flat certification fee, or a fee cost applied to each amp?
Its a fee for the design, not individual amps. So the more amps the more its amortized. That's just the EU BTW...
Lol...I just wanted this thread to focus on the manufacturers offering the GaN-FET class D tech, that is all. No need to take offense, folks.
Hi guys 
Im sorry, but I've got lost on this thread. 
Too much technical infomation, but has anyone heard any of these amps with GaN technology? 
If so, has him compared it directly to any premium class A or class D amp?
Cheers
Pedro 
plga
If so, has him compared it directly to any premium class A or class D amp?


All there is are reviews so far, some making sound quality reference to other topology’s. (see first post) No one here has yet purchased one.

Cheers George
Technics R1 setup. At their showroom in Osaka.  No Eq, no snake oil cables or funny cups of water.  I was impressed and humbled.  

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.



right now its a $15,000 entry fee to get into GaNs. To rich more most of us here.


This statement is incorrect and misleading, as the GaN equipped Technics SU-G30 is only $3999 rrp even cheaper with a haggle, and it’s a complete Network Integrated Amplifier also does MQA, if your into it.
https://www.technics.com/us/products/grand-class-g30/network-audio-amplifier-su-g30.html

Quote: "The musical reproduction offered by the Technics SU-G30 was among the best sound of any amplifier I have ever reviewed. It is ironic that the better digital gets, the closer it sounds to analog. Tubelike even. This is how I view the audio prowess of the Technics SU-G30 – it is like analog, super clean analog at that. My generalized listening impressions involved excellent purity of tone, a huge soundstage, amazing detail retrieval along with surprising excellence on streaming services."


Some reviews:
https://hometheaterhifi.com/reviews/amplifier/integrated-amplifiers/technics-su-g30-network-audio-am...

https://www.richersounds.com/technics-stereo-amplifier.html

Cheers George
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.
'Digital amp' is a marketing term. The description above describes a class D amplifier with a digitally controlled front end.
The Man Said,
 "Not to mention Class D is most efficient and runs cooler so you save on power bills"
   Sounds nice to many
people   But to me i want sound first  
then worry about Bills
and Heat 


@twoch +1
If you afford HEA you can afford electric bills.

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.  

It is not clear whether the cheaper Technics is a digital amp or a class D amp.


Really??, it's Class-D.
If you need proof under "Design" 3rd paragraph down.
https://hometheaterhifi.com/reviews/amplifier/integrated-amplifiers/technics-su-g30-network-audio-am...

I finally got a response from Soundigital and they said they are $800 and have warehouse stock in Florida.
Sounds like a viable re-badging/re-casing project.

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.

ricevs, you might be over-reading the review a bit. I interpret the Technics design architecture (from the Technics website) to reflect a configuration comprising a DAC, an analog Preamp and Class D Amp. The digital inputs are fed to the DAC for conversion to analog signals. The preamp section processes and amplifies all analog signals from both the DAC and analog inputs before sending them to the GaN-FET driver stage of the amp section.