New Generation Class D - AGD Audion Mkiii upgrade

In agreement on every point.

I would like to take a moment to add my experience with AGD, The Audion's in particular, and my personal experience with Alberto Guerra, who is AGD's Principal designer/owner.

 In 2022 I purchased a second hand pair of The Audions in the matte grey finish, with the MK II tubes. The speakers that I would be driving them with are the Legacy Audio Aeris, which are rated @95 db at 4 ohms. They have built-in powered subs, so the Audions would thus be only required to power the mids/HF drivers...So I felt confident that the Audion's 170 watts at 4 ohms would power the Aeris adequately, even though prior to the Audion's I was using Legacy's own iV-2 Ultra dual mono amp, rated at 1000 watts per channel x 2 @ 4 ohms.

Once I received the used amps, I contacted Alberto to have the remainder of the amps warranty put into my name. We spoke at length on the phone, and Alberto could not have been more pleasant to deal with.

Upon hooking up the Audion's to my system, I must say I was absolutely stunned at their performance! I have been in the hobby since the mid 70's, I have attended 20 years of Las Vegas CES, and I have had the pleasure of hearing many a satisfying sound system's in that 20 years. Over the last 45 years of owning and building my personal 2 channel rigs, I have had the pleasure of owning speakers of all designs from dynamic, electrostatic, horns, bi-poles, di-poles...and just about every kind or type of amp: Solid state, tube, class A, Class A/B, and class D.

In my opinion, in my system, and to MY EARS...The Audion's provide me with some of the midrange tonality of the best tube amps I've owned: Audiopax Model 88, which powered my Avantgarde Duo Omega's like a dream! The Audion's soundstage/image BETTER than any amp I have owned, and providing me with all the slam and dynamics of the best solid state amps I have owned.

Late in 2023, Alberto contacted me and asked if I would be interested in the new MK III "tube"? After hearing his explanation of the improvements in the new design, I decided to give them a try. Holy Moly! Another home run hit outside the ballpark by AGD! I did not expect to experience the improvements that I heard. It did take awhile for the new "tubes" and the circuitry to "settle-in", but when it did, the smile was a mile wide! It wasn't long after that I was hearing the full impact of the Mk III upgrade, that I contacted Alberto via phone call to tell him just how much I was enjoying the amps/new tubes. For a man who is apparently a "One Man Show" as far as being the company President/Designer/Builder/Shipper, etc. he very freely gives his customer's more than ample personal time via the phone. I told Alberto that these amps were my "Desert Island/take them to my grave/last amps I'll ever want or need"...EXCEPT...In the perfect world, I would LOVE to own the polished versions. And I'll be damned if Alberto didn't have a card up his sleeve to make that happen too!

So here I sit, with the latest Shiny/Beautiful Audion's with MK III tubes, and in my 68 years of owning and building pretty damn nice 2 channel music systems, I can honestly say, that I have NEVER owned such a musically satisfying system...EVER! I firmly believe these amps are one of the very large contributions to that statement. I would wholeheartedly encourage anyone who is curious about the sonic benefits of AGD amps to audition them. Life is short...but these amps will make you want to live for eternity!

(Oh, and for the record, I really like the LED glow of the GAN tube, I think it is part of the physical beauty that matches the audible beauty! Just My 2 cents)

Tim

My recently purchased Audion MK111's took about 50 hours to start really singing.

They are fronted by a well broken-in Primaluna EVO 400 tube pre-amp. This pairing seems to be working very well. Hearing things I had not heard before and having fun again.

Alberto's customer service, as well as the ,Audion mono blocks, is excellent!! 

I have the AGD preamp in my home right now running it on my existing Class A amplifier. All I can say is it's simply superb in almost every way. I could stop right here and be perfectly satisfied but alas I am going to listen to the Audions courtesy of Alberto. 

Mainly writing this in this forum as an endorsement for his non Class D hifi gear. This preamp is incredible and has very little to do with GANS and Class D. This is the real deal hifi gear and company. Take it from a guy who's been on the merry go round for 25+ years. 

I am a fan of the glow, also. Of course, the sound is pretty good, also..😁

@Peter_s I think you will be delighted with the Mkiii tubes. Mine sounded great immediately but got even better after a few days. Would be interested to know how you get on with them.

Interesting that non-audiophile visitors often seem to really like the LED’s. I actually like them but, as you say, the convenience of plugging new ones in when an upgrade becomes available is a major plus point.

BTW - I in no way think of the Audions as having tubes.  I would be fine if the “glass envelopes” were opaque. I don’t really like that they glow with LED’s.  But I am willing to overlook all of that further sound, and the convenience of the upgrade. I will soon receive the version three upgrade, and see what I think.

I had both the Audion II’s and the Atmasphere Class D’s at the same time and preferred the Audions. They are fast, neutral, delicate, well balanced and have a very black background.  I found the Atmas to have a bit of graininess in the upper mids.  They were a bit weightier.  There was a slight transformer hum, which might be abnormal, but that put me off a bit.  

@nadimjaber , I have not tried them with any other pre, but will soon, as I recently purchased ( happy birthday to me!) an Ayon CD-35 that is also a pre amp. I am currently listening to it through the PL and will be trying out the pre amp side side soon. 

@rajugsw Jay is correct.  The GaN FETS that Alberto is using were initially designed, they were designed with audio in mind.  Not claiming each company that uses the tech doesn't have all kinds of additional proprietary implementation secrets, but they are nearly all using chips designed for other things.  Whether you think that makes any difference is up to you, but the AGD amps are incredible devices,  They combine amazing design, fabulous sound, and easy upgradability in a way that no one else touches right now.

After several weeks of use with the Audion updated to MK3, I am very happy with the sound, it has been a worthwhile update. Congratulations to Alberto for allowing this equipment update system. It is a pity that in Spain there is no representative from whom you can request proof of the previous Alto. Now my audio distributor has let me try a solid preamp from the German brand Trynity and it gives a good sound, but I think that before making any decision to purchase the definitive preamp for my system, try a good tube preamp. I think Jay's uses Allnic with his Audions.

Giantsalami 

Thank you very much for the recommendation. I have not been lucky enough to hear Primaluna, I know that it has good reviews and the price is reasonable (just as the prices of HIFI equipment have been set). In addition to the Primaluna, have you paired the Audion with any other preamps?

@mbmi I have 2 pairs Bose 901 Series 1 & 2’s stacked for my Surround Channels powered (@4Ω) by a 3 Channel custom GaN FET made by me Orchard Audio Ultra (500WPC) Amplifier.

BTW....Yes GaN chips are used in power supplies as I humorously mentioned in my Video.

. Alberto recently got into a battle of words with Ralph of (I stayed out of it - I’m on Ralph’s Karsten’s side here). I’ve heard Ralph’s GaN Amps on a pair of PS Audio FR20’s and they sounded fantastic. I never got to swap in Leo’s Orchard Ultra Amp cause the dude sold the FR20’s !! At 40% of what he paid for them !!!

I think Jeff B still has Ralph’s Amps. Not sure. If anyone can make a GaN FET Amp sound like a tube Amp. Ralph is the Man !! But Leo’s Amps sound amazing with a Tube Preamp in front of it (just ask Zeos).

I am running a Primaluna 300 evo pre, which sounds fantastic. You would have to get the 400 for the balanced outputs.

Hi, I already have my MK3 upgrade from my Audion. I'm in the burn-in phase, it will take about 25 hours and I enjoy the sound of my Audions. I wouldn't know how to discern now between the sound of my Mk2s and this new Mk3. The memory of a fish has those things, and I think it is essential to wait for the burn time that Alberto recommends of 150 hours to make a serious comparison about the sound between both tubes. Beyond that, I'm really liking the sound of the Mk3, but I also really liked the Mk2. At this point, my question is which preamplifier would be recommended to use in my system. I try to explain the complexities of it: I have analog sources that require the preamplifier to have a line output and RCA and XLR inputs. Two digital sources that require XLR inputs. So it is necessary for the preamplifier to have various inputs and outputs

@tweak1 

Were you addressing me? I'm not the OP.

I love the smell of napalm in the morning and especially so when the battles are likely to benefit us all in the long run.

OP

you would need to research it

@tweak1

Is there a reason why you think the Voyager Gan amp is superior to the March purifi?

@roxy54 

You can score used LSA Voyager 350 GaN amp for ~ $1800, have it shipped to Ric Schultz (Tweak Audio) for mods and be beyond happy; You might even find a modded one ~$2500

HTH

I can't afford Ralph's amps, much as I'd love to get one, or the AGD amps, but I have my eye on the March Audio amps. Owners seem to love them. 

I am a fan of the AS Class D (I own a set)

I have not heard the AGD so can not comment on the sound

I believe BOTH companies designed a GanFET Module from the ground up for their own purposes. Building an amp with the sound characteristics that they felt was best.

Although an easy, at home upgrade is awesome, so is an upgrade that includes new Caps, resistors, and other parts I am not comfortable doing myself. Again, probably an individual preference so we should not be insulting one another over which one they prefer.

@arafiq - I, too, would be willing to do an at home audition between the two (if someone wants to let me audition their AGD lol

Good point, sir.

@dseltz I'm sure they are.  Ralph has certainly been successful for a long time and probably has a great plan in place.  I just love the idea of not having to send the amps back for updates and having the updates essentially delivered to you.

I believe BOTH amps are easily upgradable.

Actually, I know this for a fact.

Always buy that which can be upgraded instead of the "one and done" inferior design that doesnt keep up with the newest technology and innovation possible. 

Yes, its always a good idea to make an amp easy to service and update!

+1 @badgerdms   Always buy that which can be upgraded instead of the "one and done" inferior design that doesnt keep up with the newest technology and innovation possible.  Better to be a Master of 1 design than a mediocre "jack of all trades".

 Both AGD and Atmasphere can send me their amps for auditioning. 
I can provide an unbiased opinion based on what I hear. 
 

@atmasphere It sure is.  That's why I ordered the AGD Audion Mkiii's 

Now, and with all due respect, the simple fact your last reply cites the "input capacitance", is an obvious demonstration of the gap in the fundamental know-how of semiconductors in general, and for sure in III-V material devices that exists on this matter from your side. For your benefit, you know, there are multiple FOM (figure of merit) indicators in every device that are application-specific and need to be optimized, together with the package and internal device layout, to reach the optimum performances (you can ask your friends at GaN System), and in the semiconductor industry, there are millions of dollars spent every year to gain small % edge vs. competition every year and with a new generation of parts to improve just a few of them.

Yeah, I have friends and customers that design semiconductors...

Boiled down, a US phrase is 'the proof is in the pudding'.

 GaN FET’s don’t need 100 of hours of break in. I proved this at friends home a while ago.

@rajugsw You’re funny.......Any true audiophile knows that electronics Always improve after an initial burn in.....gear, cables....even your 4 K TV....you my friend must have a Sansui integrated with Bose 901’s.

@abd1 

I've had the AGD Duet's for about a month now - these are AGD's new monoblocks, 300 wpc at 4 ohms .  I'm using them with YG Hailey 2.2 speakers and Playback Designs MPS-8 DAC and MPX-X streamer (using the MPS-8 variable control with no preamp).   I'm very happy with the sound, the AGDs easily drive the speakers and work very well in this system.  I think they are a very good match with the YG speakers. 

As someone who owned the first modded LSA Voyager and now the PeachTree GAN1 (also modded). My preference is the GAN1. I finally got the GAN1 back playing tunes (needed another streamer). It is such a good amp. I only use it now for my RAAL CA-1a headphones and you hear what an amp can do with the RAALs.

Only negative I had with the GAN1 was that it was not powerful enough for my Yamaha NS5000 (use a CODA #16 with it) and it was also not powerful enough for the Magnepan LRS+ (use a Sanders Magtech amp with it).

The modded GAN1 sounds as good (maybe better in some ways) than those 2 amps.

Not selling any of those 3 amps nor can I since I tossed the shipping boxes. 

Although at some point I intend to send Ric my LSA Voyager (I am one of the lucky ones to have his dual mono EVS 1200), my stock Voyager is very livable

The LSA Voyager GAN with mods is one helluva amp. It’s error is by omission not commission. Beautiful mids, extended crystalline non-fatiguing highs. What it gives up to the Class A and AB behemoths to my ears is meat on the bones from the midbass on down. That’s about it.

@roxy54 

1+++++

Ouch!  And then "Happy Thanksgiving"? I think that's what's called a sh*t sandwich.

@atmasphere 

I have never read a rude statement from you on this forum, including on this thread.

Dear Ralph,

my position is supported by the quality of the sound of what we make (and what I designed from the ground-up...literally), and also those few decades spent in a much less fun environment than Hi-end audio...meaning the semiconductor sector.

Now, and with all due respect, the simple fact your last reply cites the "input capacitance", is an obvious demonstration of the gap in the fundamental know-how of semiconductors in general, and for sure in III-V material devices that exists on this matter from your side. For your benefit, you know, there are multiple FOM (figure of merit) indicators in every device that are application-specific and need to be optimized, together with the package and internal device layout, to reach the optimum performances (you can ask your friends at GaN System), and in the semiconductor industry, there are millions of dollars spent every year to gain small % edge vs. competition every year and with a new generation of parts to improve just a few of them. So it is fruitless to take this venue and continue an argument over a true statement, or transform it into a "Power Electronic 101 for dummies" type of training. Also, on the same token, and maybe I need to ask forgiveness for this ;)...well...I need to confess... I am definitely and categorically not interested in telling the "secrets" about how to make a better GaN for audio to my good competitor!  Right ?? ;)

So really, in all honestly that was not my goal, I simply wanted to re-iterate what I have said, written, and publically declared, sorry if you keep ignoring the evidence in a sort of "don't look up" style.

The results of the AGD products are the proofs and for the rest, well let's leave it as is, and let's enjoy the music again, in whichever form is reproduced :)

 Thank you and have a nice Thanksgiving!

All the best!

@agdproduction The reason I responded the way I did is because your 'explanation' lacked anything that pointed to an audio application. So perhaps you could be a bit more specific. For example, having a lower gate capacitance as advantageous, but that would be a benefit to any switching device. So in order to support your position, you would need to be very specific about how the GaNFETs you use are somehow different from regular GaNFETs in a way that favors audio without favoring switching devices in general.

I had thought that was clear from my prior posts; I apologize for my lack of specificity in that regard.

@atmasphere 

I don't think I misunderstood your post, you replied to our true statement about the fact we use a specific GaNFet HB device that was specifically designed and optimized for CLASS-D (Audio) applications as not true. That was already borderline offensive since your comment implied I was making up something or worse I was a liar. Nevertheless, I very gently tried to explain the reasons and the basis of my statement, and still, you ignored them and made a further simplification inherently calling me a liar or incompetent, by saying that all GaNFet as long as are "good switching devices" are good for Class-D anyway. They are not, and you can repeat that all the time you want, it will not make it right. In any case, I found this type of argumentation a total waste of time, if you wish to get a more comprehensive explanation just give us a call and I will be glad to re-explain my statement again, for the last time. 

@Atmasphere

1++++++++++

@agdproduction

Does the ability to build a GaNFET class D of our own design from the ground up, have it meet EU Directives and get nice comments about it and such, that I somehow I am

misunderstanding the explanation and the physics of the semiconductors applied to power electronic technology and applications

seem true? Not sure where this is coming from- its not something I'd say about you in the face of similar evidence. So I have to conclude you misunderstood my post.

@atmasphere 

Well, what can I say, I am very very glad you keep misunderstanding the explanation and the physics of the semiconductors applied to power electronic technology and applications :)

@agdproduction Your description simply sounds like a good switching device (i.e. GaNFET), combined with good engineering arranged to make an amplifier. I'm very aware of the difference between efficiency and good sound :)

well, that sure clarifies a few things...🤔😁

@atmasphere 

Sorry, but what you are stating may be applicable to the rest of the GaN MOSFET but that is not correct for the device we use in the Audion GaNTube88KT and I will be more than happy to describe to you why.

Without boring anyone with complex terms, in short, the reason is simple.

Since you know very well the difference between fixed D% (i.e Buck or Boost converter) and variable D% (i.e CLASS-D) operations, symmetrical HB and asymmetrical HB configurations, and among other things how important the stray inductance of the switching pair at the switching node is (we switch our power stages at ~800KHz but we could go much higher...), you should easily derive which parameters and physical elements of a semiconductor device (the 3 terminals switch) need to be optimized to make it operate at best in each different topology with the ultimate goal to obtain not just the best efficiency....but in our case, a great sound...and these parameters are not the same. I assure you ;)

@atmasphere I understand but before International Rectifier got bought by Infineon, they were working on an audio solution.  When that project got scrapped I believe Alberto bought all of the product produced to that point and began the process of designing and building his amplifiers from that stock--which had been produced with audio as the end game,

I have the MK III for about 2 weeks now and am just impressed at the clarity and sound they produce. Immersive is a good description. I am thoroughly impressed and satisfied with these.