Gallium Nitride Amps, just how good do they sound?

[Cafad]

Have you heard of Gallium Nitride?  Have you heard what it is doing for class D amps?  If so, cool, welcome fellow interested personage.  I'll do my best to keep you entertained for a while.

 

If not, let me provide you with a 2-and-a-half line summary.  

Gallium Nitride is a semi-conductor, much like silicon, that has slightly more favorable electronic characteristics.  Electricity can move through it faster, enabling transistors made from it to switch faster.  GaN (as it is becoming increasingly abbreviated to) class D designs can supposedly switch twice as fast as old school MOSFETs.  Several companies are dipping their toes into the GaN pool.  Panasonic, Peachtree, Java Audio and Orchard Audio all have GaN based power amp offerings on the market (or at least Peachtree should by now) but not a lot of people have heard them.  They aren't that popular... yet.

 

I have an Orchard Audio Starkrimson amp (and DAC for that matter) that I am running in at the moment and it is very good indeed.  It is clear, clean and powerful while also being resolving, delicate and non-fatiguing.  I suspect I can get it to sound even better again as I haven't yet gotten around to trialing it with different speaker and interconnect cables.  

I also have some Purify 1ET 400A modules on hand which I plan to assemble into a power amp just as soon as I can get my hands on a case and power supply.  

 

I'll share my thoughts on the amps, their sound and performance as time goes on but for now I'd like to hear from others.

 

Have you heard a GaN design?  If so, do you have any comments you would like to share?

Edited February 21, 2024 by Cafad

[PKay]

@georgehifi

[georgehifi]

12 hours ago, Cafad said:

Have you heard of Gallium Nitride?

I'll share my thoughts on the amps, their sound and performance as time goes on but for now I'd like to hear from others.

Have you heard a GaN design?  If so, do you have any comments you would like to share?

 

I have yet to hear any, but the Peachtree GaN 1 (digital input poweramp) and their Carina GaN (mulitple digital inputs integrated) I would love to hear as I believe this is the path for the future of Class-D. "Digital from input all the way through to the output stage (GaN devices), and yet without the need of global negative feedback".

 

I believe in GaN so much so that I purchased Aussie SLX shares at the time (for $1.17, last week hit $5.70) who mine the ore in Australia for the making of these class leading output devices made in the US, which will probably make todays mosfets that are used in Class-D obsolete, because of all the parameters outlined by Cafad, not just the higher switching speed, but able to run with no global negative feedback, many more pluses as well.

 

Here is one New Yorker (DIY Audio member since 2004)  that's non affiliated, that that listened to the Peachtree GaN1 and A/B'd it up against a pair of very high end Classe monoblocks on very hard to drive Apogee Duettas.

 https://www.diyaudio.com/community/threads/peachtree-new-gan-1-all-digital-amplifier-the-future-and-its-not-class-d.403541/page-23

 

Look forward to anything Cafad or anyone gets to hear, especially the Peachtree Carina GaN a one box solution, or their GaN1 poweramp both which use "no global negative feedback" just a little "local feedback", which has always sounded far better to me when I've a/b the two. With "local feedback" they are more stable, and  "if" the amp still has good low output impedance (damping factor) with just a little "local feedback", bass is just as controlled. 

 

Cheers George  

Edited February 21, 2024 by georgehifi

[075Congo]

Just thinking of a company based in Sydney which markets Amplifiers/ Phono Stages and Pre-amps. Their production has been curtailed for over 12 months mainly due to a shortage of a particular semi-conductor. Wonder if their designers have explored Gallium Nitride. Still exploring current GaN stock prices but I probably missed the boat.

Mick

[Kirby66]

Hi @Cafad, I had not heard of GaN till now. Thanks for raising the topic and starting the thread - I will follow with interest. 

[georgehifi]

3 hours ago, 075Congo said:

Their production has been curtailed for over 12 months mainly due to a shortage of a particular semi-conductor. Wonder if their designers have explored Gallium Nitride.

Trouble with that is cost, the circuit boards that they have stocked up on, would have to have a complete redesign track layout to accept the GaN Fet etc, over the stock old school mosfets etc.

 

Cheers George

Edited February 21, 2024 by georgehifi

[075Congo]

That fire in a Semi-Conductor factory (RENESAS)in Japan in 2021 and which was struggling to open its production lines put a huge hole in various industries. Hopefully the redevelopment of replacement companies within the USA will help as well. At the time there was a "perfect storm of issues in Texas and Taiwan re semi-conductor supply". Wonder what effect this has had on local industry?

Edited February 21, 2024 by 075Congo

[Cafad]

Hey George, good to see you here since your Peachtree thread helped push me further along the GaN path than I was already.  

 

Your mention of feedback has me puzzled.  I thought the new Purify amps used bucketloads of negative feedback and that was whey they were so stable but I just spent the last 30 minutes trying to find out why I thought what I thought and I couldn't.  I'm sure I read it somewhere... my search will have to continue later.

 

If anyone finds any interesting links to GaN related articles or posts please share them.  I'm always up for some reading and I'm sure others are too.  Some of the links that got me hooked are listed below.

 

https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-purifi-1et400a-amplifier.7984/   Amirs' measurements of the Purify 1ET400A modules (with the dual input eval board, which is exactly what I will have to work with when all the bits arrive.

 

https://audioxpress.com/article/fresh-from-the-bench-a-tale-of-two-class-d-amplifiers-orchard-audio-bosc-and-purifi-audio-eigentakt-eval1  There it is, extremely high amounts of feedback, although there is also some feedforward so feedback is not used exclusively.

 

https://orchardaudio.com/starkrimson-gan-technology-implementation/  Some info from Leo's Orchard Audio site, a few more links are listed at the bottom of the page.

 

I'm not going to pretend to know much about investing in upcoming tech but if I were going to invest in anything GaN related I'd probably be looking at Purify since they have products already and they are designed to be used by other manufacturers.  

 

I'm going to have to look up negative feedback now.  I can't recall Leo saying much about it so I'm guessing that he and Purify have made different design choices.  And Peachtree different again.  I like it when things get more and more interesting.

[075Congo]

Interesting article by Jerry Del Colliano titled "What the hell is a GaN amp" from Future Audiophile (www.futureaudiophile.com). Worth a read.

[sir sanders zingmore]

52 minutes ago, 075Congo said:

Interesting article by Jerry Del Colliano titled "What the hell is a GaN amp" from Future Audiophile (www.futureaudiophile.com). Worth a read.

Link here:

https://futureaudiophile.com/what-the-hell-is-a-gan-gallium-nitride-amp-and-why-is-it-changing-the-way-audiophiles-now-see-power-amps/

[075Congo]

Reading in that article the number of differing Gallium Nitride amps currently being sold and the features/power they offer......including a $35K amp from the Jeff Rowland group.......there is certainly a "New Kid on the Block".

[georgehifi]

2 hours ago, sir sanders zingmore said:

Link here:

https://futureaudiophile.com/what-the-hell-is-a-gan-gallium-nitride-amp-and-why-is-it-changing-the-way-audiophiles-now-see-power-amps/

Good article, but they didn't delve further into the best of GaN, that they can take 3 x higher switching frequency speed (1.5mhz!!) than fets used in todays Class-D's 600khz, and that why if you can find one the $30kaud Techincs 54kg SE-R1 poweramp with linear power supply sounded so good, mostly because the 1.5mhz switching frequency used (in combination with 3 x higher low order LP output filter) instead of the standard 500-600khz switching speeds used, that's why it was said to sound so good for a Class-D amp.

 

I remember seeing this AGD "tube" GaN amp when I first started on about GaN a couple of years ago and got punished for saying it's going to be the future of Class-D.

The tube thing is a gimmick on the AGD amp, just GaN amp module transplanted in an empty tube, with red leds to simulate that tube "heaters" are on?. They'll probably tell you it's for airborne isolation or something that it's inside a empty tube. (the audio industry sometimes really )  Most people aren't that silly I hope.

Cheers George

Edited February 25, 2024 by georgehifi

[075Congo]

The StereoNET arena is a good area for being "punished"........

[georgehifi]

18 minutes ago, 075Congo said:

The StereoNET arena is a good area for being "punished"........

 

I don't mind too much when it's from the non-affiliated/commercially unconnected ones, that know what they're on about.

 

But when it comes from those with monitory incentivized agendas, that are associated or in similarly connected field/s, that gets my back up, when they come into a thread just to sneakily and in an off hand way push their own product which is "off topic" anyway.

 

Cheers George 

Edited February 25, 2024 by georgehifi

[Bell Ringer]

Darren Myers ex PS Audio  now Parasound has reinstated the podcast with Duncan Taylor. https://the-hifi-podcast-with-darren-and-duncan.simplecast.com/episodes/all-about-gan-fets-mitski

He mentions that Bruno Putzeys is still using mosfets. 
 

[georgehifi]

56 minutes ago, Bell Ringer said:

Bruno Putzeys is still using mosfets

 

When younger I worked in the photographic testing equipment manufacturing field, cameras testers/colour analyzers/flash meters etc  etc

 

When your geared up and stocked up with pcb's, semiconductors, caps, enclosures etc etc with the many thousands even millions spent already on having all that in stock to manufacture your product/s with. It's a BIG ask to almost scrap it all to change it for something mid stream that not a "direct replacement" for what your using already which a GaN is, it's not a direct replacement.

 

So time will tell if Bruno/Hypex/ and all the others big ones come on board with GaN later when they get rid of what stock/s they have. Smaller companies can as their investments are not as large, and new companies can as they have nothing to loose and everything to gain, and they do if you notice who's taking GaN on board now. 

 

Cheers George 

Edited February 26, 2024 by georgehifi

[Misternavi]

I have the Strakrimson 150W GaN amp, I also have a +20yr old Class AB Benchmark A200 & Lm3886 chip amp.
I prefer the Benchmark as when I did a comparison the Starkrimson. The bass was a lot meatier on the Benchmark.

 

I think the Starkrimson would be amazing with active pre amp with tone controls, even direct driving from a DAC seems lacking. The Murata power supply is also very noisy.

 

I still have mine and maybe my next thing to try is having the amps next to the speakers and having super short speaker cables. I do wish to make it my main power amp again as it uses very little power when on and Not in use.

[georgehifi]

https://the-hifi-podcast-with-darren-and-duncan.simplecast.com/episodes/all-about-gan-fets-mitski

 

What finally has been said publicly (beside by me) about GaN in the Podcast by the Parasound engineer is the higher switching frequency advantages (hence higher output filter that comes with that) and the big one that comes with those, the much less phase shift down into the audio band because of the higher switching frequency and output filter, and that's big advantage they have over today's fets in todays Class-D's.

This is talked about at 26min 20sec to 28min 20sec on the podcast, try to stay with it.

 

This is why the massive and rare Technics SE-R1 got raved about for it's sound quality especially the upper/mids and highs for Class-D. 

 

Cheers George 

Edited February 26, 2024 by georgehifi

[Cafad]

Well all my bits have arrived so first item on my Saturday to do list is to figure out how to assemble this Purify power amp.  Then while it warms up I have to check out this podcast mentioned above.  I guess I should take some pics as well.

 

It's almost time to get loud. 

 

And just like Big Kev, I'm Excited! 

[Cafad]

Almost there, wired up but I don't trust previous evening me to have done the job right so morning me must check over the wiring again to ensure no instant cooking takes place.  Also, Friday afternoon me left my phone on my desk at work so pics have not been taken (so obviously I can't close the case yet).  Hopefully one of the guys on night shift will remember my call (made from the work phone) and drop my phone off this morning.  I'm really not great at this organizational stuff.

 

I guess I'll have time for some podcast listening while I wait.

[Cafad]

Well it would appear my hamfisted assembly is complete.

 

All parts assembled, check.  Several screws left over, check.

 

Lights turn on, check.  Lack of smoke... check.

 

Excellent, now let's move on to the more satisfying (hopefully) side of the hobby.

[sir sanders zingmore]

On 26/2/2024 at 12:21 PM, georgehifi said:

the much less phase shift down into the audio band

George please don’t start this again. It was put to bed (by you ) here:

https://www.stereonet.com/forums/topic/593227-peachtrees-gan-1-carina-gan-all-digital-amps-the-future/?do=findComment&comment=6258162

[georgehifi]

 

That was almost 6mths ago it was bought up.

These two respected "audio engineers" Darren Myers (from Parasound), Duncan Taylor (from YG Acoustics), have woke it back up in a podcast and got it back out of bed.

 

They talk about it at 26min 20sec to 28min 20sec on the podcast for those interested into drawing their "own conclusions" if they're thinking of going down that path.

https://podcasts.apple.com/us/podcast/the-hifi-podcast-with-darren-and-duncan/id1532674642

 

Cheers George

Edited March 5, 2024 by georgehifi

[Cafad]

OK, final hurdle cleared (I think).  I set up the amp and powered it up and got myself a moderate level hiss from the left speaker.  Not related to input as when I pulled out the input IC nothing changed.

 

Apparently I forgot to change the jumpers on the Hypex board.  They come set to regulated auxiliary voltage but the eval board has its own regulation so the jumpers need to be changed to unregulated.  Fairly simple but it would have been very useful to have much smaller fingers.  

 

And now we have music.  

 

Also, pancakes.

 

Because as good as you can get your system to sound, it'll always be better with pancakes.  They make everything better!

[Cafad]

And testing has begun.