GaN amplifier from GaN themselves limited supply!!!
There is this integrated GaN , made by GaN themselves, so you know it "should" be good. (Could very well be the best of all GaN amps) (single purchase only, not available for multi purchase for commercial Class-D manufactures)
But you’ll have to put it in a box, comes with all you need, the amp and power supply, and dac??!!! (if you can build simple kits you can build this, would it quite simple to make up) . You have with it: Volume control 3 x switchable inputs 2 x Analog stereo inputs rca & jack 2 x digital spdif inputs, optical and coax (yes it has a dac in it too) And this is neat, user variable negative feedback!!! for those that don’t like too much for the sake of "better" measurements" and want a more organic sound, all for just $1.3K
The fact that these have sold out is probably not due to popularity in the high end audio community so much as GaNFETs are hard to get right now and there probably isn't stock to build the evaluation boards. When you can't get the product to sell, why in the world would you populate a promotional product??
I noticed George repeating himself in his quotes from Amirm but oddly he leaves out Amirm's concluding remarks so here they are from Amirm's website:
Conclusions
MOSFET transistors have revolutionized computing and switching power
designs. It is nice to see a new type become available after decades of
refinement of MOSFET. GaN transistors offered by GaN systems show a
path to cooler running, more efficient and better performing amplifiers
and power supplies. The eval unit unfortunately doesn't show the
improved performance due to different target for it. So best to look at
commercial implementations that shoot for state of the art
implementations.
Any chance of doing the couple of measurements again that didn't impress
like the others did, but with the feedback set up higher where you
think it should be, as this may well flip your conclusion around??.
Obviously George is aware of Amirm's conclusion.
Amirim indicates that he is concerned the evaluation board will go into oscillation if too much feedback is applied (for those technically minded: with too much feedback the phase margin of the circuit would be exceeded, resulting in oscillation). This is a clue into the design of the circuit. It indicates that its not self-oscillating. Since it can also be run with zero feedback (see measurements on page 1 of the review) this suggests a straight forward Pulse Width Modulated encoding scheme.
A PWM encoding scheme with no feedback has noise associated with frequency drift in the triangle wave oscillator. For this reason the oscillator has to have a lot of attention paid to its stability, but the simple fact is it will drift. You can see the result in the noise spectrum which is the final measurement Amirm shows.
One more thing: If you note the 4 ohm power measurement as opposed to the 8 ohm power you see that its actually **lower** (114 watts) than the 8 ohm power!
This is not a mistake.
I've already said why earlier on this thread- because the eval board is for evaluation only its not supplied with heatsinking means. Heatsinks that can actually allow the amp to run at full power into 4 ohms are not a trivial cost- they would be the most expensive part(s) in the kit due to the precision machining required. So the amp is teamed with a SMPS unit that is unable to provide the current needed into 4 ohms (and is probably actively current limiting). This prevents the board from overheating its output devices.
So if you are planning this amp as your power amplifier, just be aware that its really only 114 watts into 4 ohms.
What is going on with this thread? The moderation appears peverse. The OP was misbehaving and got defensive. Then everyone else's posts got removed? What a strange place this is. Reminds me of the Tekton thread where any opinion on the speaker's appearance was removed. So we can discuss components but not their appearance? It seems some, rather shrill in tone posters, get to wag the dog
Looks like there must have been a few purchases done since this thread went up, as they’ve now run out of stock. It says you can still back order though, 10 more units expected on the 28th Oct.
Here we have the video on the $1300 Gan by Gan Class-D and Power supply, fully loaded with a dac, volume control, switchable inputs two digital and two analog and variable feedback (closed loop/open loop) this is plug and play almost, all you need is a box.
44th minute onward shows you how to use the feedback control in real time while listening to pick the right amout to suit your liking, so listening comparisons can be made. And as I said it also the Scamp connection which also gives many DSP control values to be had via you laptop.
There is is the development stage another one from GaN which they call the Reference board which sounds to me like it could be even better? That could take a while though.
Do you know what the RCA input impedance of this board is, as I've looked and can't find it anywhere, maybe Rick Reigel could let you know if you don't?
The first mentioned history of the new GaN output devices here on Audiogon
The new GaN transistors were reported here some 4-5years ago about how they will transform Class-D, especially the way Technics used them with the SE-R1 and it’s 1.5mhz switching speed instead of what everyone else uses around 500-600khz.
And dht4me who has been in direct contact with Rick Reigel from GaN, says there is another "Reference Board" in the design stages.
This present unit bodes very well for the members here who can do very simple kit assembly themselves, basically mount the GaN board it in a box add some rca sockets and speaker terminals.
You got a killer Class-D GaN integrated amp with dac!! and variable feedback for well under $1500 that "could" blow any others here away, as dht4me reported when he demoed it to the LA audio crew and said, "I have built 4 of these to date, the first was for me but as soon al local Las Vegas audiophiles heard it they were begging me to build them one."
Yeah, thats the very confusing part. Ralph has said nothing negative about the tech, just calling out application.
Meanwhile, George gets to throw his vitriol about.
Not cool...
And I am also curious about the new tech that is around the bend. Especially curious when a designer like Ralph does what could be argued as a complete 180 from OTL tubes to D class amps.
Yeah, my prior post got deleted as well. George gets very defensive whenever anyone questions anything about things he recommends here to the point where when even very knowledgeable and respected people here bring up valid points he feels the need to lash out at them and tries to discredit them by saying they have an ulterior profit or business-related motive (total bunk BTW). Oddly his unfounded claims against the reputations of these respected members are allowed to remain for some strange reason while posts questioning George’s motives or claims get deleted. Frankly I don’t get the double standard, but whatever. Still interesting to hear about amps made with these modules and exciting to see where the newer GaN, Purify, etc. technologies are taking the world of amplification.
Designing an amp is a bit more involved than making a volume control…
Perhaps Ralph, who knows a thing or two about what an amp can sound like, is applying that knowledge to the D class amps - which are at the Beta stage (look at the link I posted) . And perhaps, building a world class amp, can take a minute to sort out, especially when you know what it should sound like.
But, feel free to keep on naysaying. Seems that is what you do best.”
This is for others that are interested in this GaN by GaN amp
Here is a test/measurement made by Amirm of Audio Science Review, one of the most highly respected sites for the truth on anything audio related.
This GaN amp complete was loaned to them by an owner for test/measurement and "it had it’s variable feedback" "set to low" via GaN’s laptop downloadable program because the owner loaned it in to him in that way, trouble is a couple of measurements won’t be as good as they could have been Amrim says that in the tests, and reflects in his conclusion statement.
"Performance here is above average compared to median of all amps I have tested (which lands around 78 dB SINAD). But it not stellar. Speaking with the designer, his focus was to keep the level of feedback low to show the advantage of the GaN transistors not needing much. He was not aiming to produce the best performance possible. Personally I wish he had targeted that given that is what we like to see here. All in all it was superb in tests and measurements all aspects that matter."
As for heat there’s virtually none.
" Again, no heatsink due to high efficiency.s for heat sinking it runs so cool there’s no need for it. Practical MOSFETs take time to switch and during that time, they generate losses in the form of heat and limit how fast you can switch them. GaN transistors aim to solve this problem as these few slides from GaN systems show:"
Distortion at high power for a Class-D is incredible
"We see that the distortion is still under control instead of shooting through the roof.!!"
"I don’t think I have ever tested a switching amplifier with this level of frequency independence. Even Class AB linear amps struggle to produce such an absolutely clean response. Amplifiers with high amount of feedback run out of gain at higher frequencies and hence distort more. Not this design."
As for me getting one, all here know I only have Class-D preference for one, the Technics SE-R1 with it’s 1.5mhz switching frequency, even this GaN by GaN I started here, won’t shift my linear amps, yet!!
For those that are interested, don’t listen to the two detractors that have nothing on their minds but to put rubbish on the USA designed and made GaN by GaN Class-D amplifier for ulterior self motives, it’s obvious and clear.
Listen to some one who has made 4 of them (which the above haven’t), and taken them to a audio listen session, and all local Las Vegas audiophiles heard it they were begging him to build them one.
dht4me I have built 4 of these to date, the first was for me but as soon al local Las Vegas audiophiles heard it they were begging me to build them one.There is another reference board in the design stages as I have been in direct contact with Rick Reigel from GaN.
As far as any tests done my AS, remember the design was built to show off the performance without high loop feedback which is what we want, trust me. The board has the ability to have open loop and closed loop feedback and the closed loop sounds a lot like my FM711 where the open loop is just another world of clarity, tone, timbre and low level details and spatial ques that are wiped out by SS designs. I have them heatsinked especially since my 2 main speakers, Apogee Divas and Thiel CS5i’s are mean speakers to drive. The GaN amps are the future of amplification, trust me, you will be seeing a lot more of these amps. They remind me of super powerful VT25 amps for medium to low efficiency speakers.
Usually, eval boards are made by Engineers who do not listen.....non tweakers. So, I assumed this board was like any eval board.....not worth playing with. If indeed, it sounds as dht4me describes.....than it could be a great thang....and made even greater by someone who tweaks....for instance,,,,,,It looks like op amps on the input (could not find the schematic). Discrete would be better. Yes, GaNs seem to be lighting up the world.....indeed.
This says it all, the two that are trying their hardest to discredit
this GaN by GaN Class-D have only their own interests in mind, and
should look after their own interest and stop putting rubbish on things
for their own monitory gains.
Who is trying to discredit this amp? Its not me; you can't find a post on this thread wherein I am doing that. I have pointed out that its likely to have heat issues, but that does not take anything away from a product meant for evaluation. Again:
It would help if more information was available. One thing seems
apparent: While it might make 200 watts into 8 ohms it will not be able
to do that for any length of time as there appears to be no provision
for a heatsink (although it may be possible to heatsink it). Without a
heatsink at 200 watts the output devices will simply overheat and fail-
probably within a few seconds but maybe a minute or two.
IOW this kit really is for evaluation and for that I'm sure its just fine.
Note Amirm's comment 'different target for it'; clearly he is aware and understands the significance of this product being meant for evaluation):
The eval unit unfortunately doesn’t show the improved performance due to
different target for it. So best to look at commercial implementations
that shoot for state of the art implementations.
This says it all, the two that are trying their hardest to discredit
this GaN by GaN Class-D have only their own interests in mind, and
should look after their own interest and stop putting rubbish on things
for their own monitory gains.
Whose trying to discredit it? You can't find any of my comments attempting to do that. You can find a number of them that are corrections of misinformation though.
dht4me I have built 4 of these to date, the first was for me but as soon al local Las Vegas audiophiles heard it they were begging me to build them one.
There you have it, thanks for posting that up
This says it all, the two that are trying their hardest to discredit this GaN by GaN Class-D have only their own interests in mind, and should look after their own interest and stop putting rubbish on things for their own monitory gains.
There is another reference board in the design stages as I have been in direct contact with Rick Reigel from GaN.
This is great news, can you please keep me (by PM) and others here updated on this?
The board has the ability to have open loop and closed loop feedback and the closed loop sounds a lot like my FM711 where the open loop is just another world of clarity, tone, timbre and low level details and spatial ques that are wiped out by SS designs.
I have built 4 of these to date, the first was for me but as soon al local Las Vegas audiophiles heard it they were begging me to build them one.There is another reference board in the design stages as I have been in direct contact with Rick Reigel from GaN. As far as any tests done my AS, remember the design was built to show off the performance without high loop feedback which is what we want, trust me. The board has the ability to have open loop and closed loop feedback and the closed loop sounds a lot like my FM711 where the open loop is just another world of clarity, tone, timbre and low level details and spacial ques that are wiped out by SS designs. I have them heatsinked especially since my 2 main speakers, Apogee Divas and Thiel CS5i's are mean speakers to drive. The GaN amps are the future of amplification, trust me, you will be seeing a lot more of these amps. They remind me of super powerful VT25 amps for medium to low efficiency speakers.
Yeah, just throw more bandaid fix feedback at it. (just like the zero auto former you push for the OTL’s into hard loads)
Everyone
know too much feedback is detrimental to the sound, that’s why that GaN
by GaN Class-D measured by Amirm had "very little feedback on it"
programed from the owner, for the sake good sound, but of not measuring
too well in certain parameters. (get with the program) and you and your
mate stop putting on everything that’s in opposition to what you’ve
got coming, not just on this thread I’ve seen but others too!
And btw you can’t cure this kind of -75 degrees! of phase shift (red) with loads of feedback https://ibb.co/S06J7hf only a 4 x higher switching frequency will move that up out of the audio band!!!
It seems there is doubt in your mind that George designed the Lightspeed
and in my mind I just assumed he did because I have no evidence to the
contrary and to my knowledge no one else has stood up and taken credit
for it. The optocouplers which are the main component are off the shelf.
The key is that they need to be well matched which I understand takes
some work, but perhaps not necessarily skill.
@clio09 I included George's quote above because its typical of his false statements regarding the topic he's addressing: the **entire thing** is false. This sort of thing has convinced me that he's good at marketing but someone else actually designed the Lightspeed or provided the basic fundamentals. Here's a DIY article on the topic:https://diyaudioprojects.com/Solid/DIY-Lightspeed-Passive-Attenuator/The circuit simplicity belies what you go through to build it as you can see. If George were able to show that he can disabuse himself of false notions when presented with fact I'd be more likely to believe he did the fundamental design work on he volume control.
That’s right he has cred with OTL tubes that’s a given. Different altogether doing SS linear or D class, no cred there yet, until his long awaited Class-D comes if ever?? So he shouldn’t put rubbish on this GaN by GaN amp before he gets some, otherwise he’ll be no better than his mate ricevs.
I see three camps here, but I've not read every post, so there could be more. Two seem very knowledgeable but are on opposite sides of the fence with respect to the viability of this DIY GAN integrated "opportunity".
I am in the camp with Arch2--isnt' this stuff made with elfin magic that I do NOT posses? Seriously, I view what Ralph and Ric point out as good examples of what I subscribe to: You don't know what you don't know... Until you study up and practice in a given area of endeavor...and then you do start to know what end is up. I would like to build a speaker one day, but ignoring the fact that one could buy the parts and invest the time and be unhappy with the end result would be well ignore-ant. Lol.
Yeah, just throw more bandaid fix feedback at it. (just like the zero auto former you push for the OTL’s into hard loads)
Everyone know too much feedback is detrimental to the sound, that’s why that GaN by GaN Class-D measured by Amirm had "very little feedback on it" programed from the owner, for the sake good sound, but of not measuring too well in certain parameters. (get with the program) and you and your mate stop putting on everything that’s in opposition to what you’ve got coming, not just on this thread I’ve seen but others too!
And btw you can’t cure this kind of -75 degrees! of phase shift (red) with loads of feedback https://ibb.co/S06J7hf only a 4 x higher switching frequency will move that up out of the audio band!!!
Also the switching frequency still has to be 4 x higher so it’s filter
remnants and phase shift are "well out of the audio band" as Technics
did with their GaN SE-R1 and maybe their SR-1000 integrated has also.
This statement is false. If there is sufficient feedback, phase shift at 20KHz will be under 1 degree even if the filter is set at 70KHz.
Also, class D amps if designed as self-oscillating (ex.: Hypex) are inherently stable regardless of load as they are **already** oscillating due to the amount of feedback they employ. You can't somehow get them to oscillate again over the existing oscillation....
unsound Another Class D that struggles with lower impedances? Yeah, I know the specific technical arguments for higher impedance speakers, but when it comes to the sonic gestalt, I seem to lean towards those loudspeakers that have lower impedances. Wake me up when there are Class D amps that handle my preferred speakers as well as the better traditional ss amps do. I’m truly hopeful that such Class D amps can be offered at a reasonable cost.
Totally correct Class-D do not like low impedances (yet) that most of the real hiend speakers have. Also the switching frequency still has to be 4 x higher so it’s filter remnants and phase shift are "well out of the audio band" as Technics did with their impossible to get GaN SE-R1
From Absolute sounds review For its part, the SE-R1 exhibits the same bold dynamics, staggering detail, and sheer volume of musical information I’m used to getting from my reference CH-Precision A1 monoblocks. Remarkably, this is true even when the Technics amp is being driven by its analog inputs. The sound from both amps is gloriously rich, pure, and grand when the music calls for it. The biggest difference is actually in the Technics’ favor: a more realistic-sounding midrange, thanks to a dollop of sweetness.
Low impedance stability and drive is the reason why I still like linear amps for my main system.
I do have Hypex NC500 mono blocks though (with no input buffer and massive linear supplies) for the easier to drive second system though. They do well there, but still have that "segregated" uppermid/highs problem all Class-D’s seem have to me (which I’m sure is the switching frequency/phase shift problem) and where that Technics should shine
"
Again, no heatsink due to high efficiency.s for heat sinking it runs so
cool there’s no need for it. Practical MOSFETs take time to switch and
during that time, they generate losses in the form of heat and limit how
fast you can switch them. GaN transistors aim to solve this problem as
these few slides from GaN systems show:"
This statement is false as anyone who has actually worked with GaNFETs knows. Sure, you can make an amp that does not use heatsinks (we didn't add any until we got very close to production) but the simple fact is that GaNFETs do produce heat and if you can't get rid of it, they will fail and often quite dramatically when they do. And you might think that you don't have to worry about shoot thru current heating up the output devices since they switch so fast, but you'll find out differently if you don't include deadtime circuitry to prevent that. But if you're just doing demo and don't run the amp at full output you can get by without heatsinks.
We expect people to abuse our products. So we built the amp so it can be at full output into 4 ohms and it can sit that way all day. That would not be possible without heatsinks! But for evaluation I'm sure this circuit board is fine. You don't need heatsinks for evaluation applications!
Distortion at high power for a Class-D is incredible
"We see that the distortion is still under control instead of shooting through the roof.!!"
"I
don’t think I have ever tested a switching amplifier with this level of
frequency independence. Even Class AB linear amps struggle to produce
such an absolutely clean response. Amplifiers with high amount of
feedback run out of gain at higher frequencies and hence distort more.
Not this design."
This has nothing to do with GaNFETs and everything to do with the design. What is being referred to here is sufficient Gain Bandwidth Product, which most amplifiers lack in order to have feedback and consistent distortion numbers at any frequency in the audio spectrum (this BTW is a requirement if the amplifier is expected to sound musical). I've made comments about this aspect elsewhere on this site. What this says is that Amir hasn't tested a lot of class D amps; Bruno Putzeys' designs share this property of consistent distortion at all frequencies, and his designs use MOSFETs.
I know sometimes it's difficult to look past the person based on their
comments and interactions with others, but George designed and built the
Lightspeed Attenuator which I've owned for over 10 years and consider
one of the best values in audio.
@clio09 I agree the Lightspeed is one of the better examples of a passive volume control. To make the devices inside do what they do (which is to say, operate in a linear fashion) takes design skill. Why do you think George designed it- doesn't that seem a bit odd?
Another Class D that struggles with lower impedances? Yeah, I know the specific technical arguments for higher impedance speakers, but when it comes to the sonic gestalt, I seem to lean towards those loudspeakers that have lower impedances. Wake me up when there are Class D amps that handle my preferred speakers as well as the better traditional ss amps do. I’m truly hopeful that such Class D amps can be offered at a reasonable cost.
You can see it a mile away, both are only here to discredit what could be disadvantageous to what they are doing to soon to come Class-D offerings they have
It is not clear why you make jabs at trying to discredit a successful well liked individual like Ralph.
From years of reading his posts it’s clear he is above those games.
Amirm’s conclusion: Conclusions MOSFET transistors have revolutionized computing and switching power designs. It is nice to see a new type become available after decades of refinement of MOSFET. GaN transistors offered by GaN systems show a path to cooler running, more efficient and better performing amplifiers and power supplies. The eval unit unfortunately doesn’t show the improved performance due to different target for it. So best to look at commercial implementations that shoot for state of the art implementations.
What a lot of people don’t know is GAN transistors on their own are no miracle they are a very low distortion ,efficient Field Effect Transistor -FET, yes they can make a amplifier noticeably better ,but other parts too need be be on par to make a amplifier special. Just one of several technologies that are up and coming, which is good for Everyone.
Ralph’s knowledge and expertise in this field is a given. I’ve owned his products for over 10 years as well. After reading several posts by Ric of late the kindest word that comes to my mind is: meh
Correct Clio, in the OTL vacuum tube field he’s very knowledgeable. (solid state/D class offerings, different animal altogether yet to see anything there)
And the other is at best to me questionable tweaker.
You can see it a mile away, both are only here to discredit what could be disadvantageous to what they are doing to soon to come Class-D offerings they have. And you can see it on the other Class-D threads, they do similar to them, also discredit or say they can "make" it sound better with tweaks.
Have you ever designed/built and sold successful products to the public?
@soix - I know sometimes it's difficult to look past the person based on their comments and interactions with others, but George designed and built the Lightspeed Attenuator which I've owned for over 10 years and consider one of the best values in audio. Quite a lengthy thread about it on this site and an entire DIY thread on it elsewhere. So in addition to designing and building it George has shared it with the DIY community.
As far as who knows what around here, Ralph's knowledge and expertise in this field is a given. I've owned his products for over 10 years as well. After reading several posts by Ric of late the kindest word that comes to my mind is: meh.
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