New Generation Class D - AGD Audion Mkiii upgrade


I have always had a preference for horn-loaded loudspeakers which, whilst typically easy to drive, can be quite revealing (good/bad) of any changes in the system. I am running Avantgarde Duo’s and have until now always preferred valve amplifiers for their mid-range and lack of fatigue.

I have heard a number of Class D amplifiers and one or two have sounded pretty good but a bit lean compared to valves. Tha changed when I purchased a pair of AGD Audion Mkii amplifiers. The Audions have an almost valve-like mid-range but with a wonderfully transparent top end and great sound-staging. It’s always been difficult to get really convincing bass with my Avantgarde’s because if you increase the bass level the low frequencies can sound detached from the glorious mids/highs. This changed with the Audions as the bass is faster, more dynamic and just overall more satisfying.

These compact amplifiers have what appears to be a valve for each amplifier. This ‘valve’ glows red and I rather like the effect. I did think this was a bit of a gimmick at first but it contains a Gallium Nitride MOSFET power stage. However, this ‘GAN-Tube’ means that if an improvement is developed you can just swap the tubes for the new version. That is exactly what I have done as AGD have launched a Mkiii ‘GAN-Tube.

I was extremely happy with my Mkii Audions and wasn’t sure what to expect with the Mkiii tubes. But as audiophiles it’s difficult to resist an upgrade. The new tubes were fitted in under 5 minutes. I’ve found most components need time to warm-up and ‘burn-in’ so wasn’t expecting too much initially. However, it immediately became apparent that, even at very low volume, there was more detail. I pumped up the volume and was astounded by the wider soundstage which extended beyond the speakers and allowed you to pick out instruments and vocals even clearer. This is something that I’ve found difficult to achieve with Avantgarde’s and I didn’t have with my previous OTL amp. Dynamics are a strength with horns and the Audions really produce a ‘live’ sound, quite startling at times. I’m not great at describing all the audiophile things but would just say that these amps make the system sound so enjoyable and exciting to listen to. They are the best by far that I’ve had in my system.

I know some people will have a hesitation over Class D amps (like I did) but I really think this next generation amps like the AGD Audions will become more and more popular once people get the chance to hear them.

rocketiii

I'm unclear as to how the Audions improved the bass of your Duos as they use active subs powered by a plate amp. Also, may I enquire as to which OTL you were using?

Very interesting and I do like the AGD and Atma-Sphere GaN amplifiers. 

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How much are these ?  There is much newer digital boards this year 

I am waiting to see when Atma- Sphere will be tak8ng the next step up in technologies , Ralph doesnot exactly state  the module 

which I feel as a ex dealer you should state the Brand and model modules you are using for you are customizing the modules,and Analog section anyway it’s not 

giving up any bodies recipes ,and in truth you should be using their latest flagship 

modules for these boards are not that expensive ,and ,realize you have to mark it up 4x minimum to sell ,and sell8ng factory direct you cut the 45% middleman.

Thanks for sharing. 
 

I had a pair of AGD’s in my system and will say they sounded good for the money. There was a bit of lack of refinement on the top end… if I remember correctly. But then I was comparing them to Audio Research Reference 160 mono blocks. I also only listened to them for an hour or so. 

The AGD monoblocs intrigue me. They seem to grab quite a few listeners. "Jay's Iyagi" on Youtube gave them lots of praise.

Hi @acresverde I was previously using (and will keep forever) an Atmasphere S30 Mkiii OTL amp. This has been a very good match for the Avantgardes with a really good mid/high range. I use the high level/speaker connection into the Avantgarde SUB225 powered bass section so the ’flavour’ of the amplifier comes through. What I found with the Audions is that the bass is clearer, more punchy and tuneful which meant I turned down the SUB225 level.

I think the SUB225’s are good to a point but seem to get left behind in the music if set too loud (or with the crossover set too high).

I should add that I also have a REL S812 subwoofer (high level connection) behind my listening position which also helps with satisfying low frequency levels. The REL sub also feels much ’faster’ when connected to the Audions.

TBH I was happy with the Atmasphere amp but I am now retired and play the system a lot each day so the energy consumption, heat and cost of valves was becoming a concern. I did consider Ralph's new Class D monoblocks but I am in the UK and there is no dealer or demo available. The Audions run cool and don’t draw much power as the Avantgardes only require less than a Watt to reach deafening levels!

www.enjoy the music.com has a short review with some good pictures of the tubes.

Please refrain from calling the glass containers 'tubes'. Mis-stating that can be very confusing to people who don't know better. They are not tubes in the true sense of the word

I have owned MANY amps (both tube and SS, including 6+ class Ds over the decades. The LSA Voyager GaN 350 is a terrific amp at a very reasonable price MSRP ~ $3000. Infrequently, one will come up on the used market for ~ $1200, don't ask me why, but Ric Schultz EVS Audio) has a great mod which would be a huge value

hth

I have a pair of AGD Tempo stereo amps that I bi-amp with. I'm very pleased with the sound. 

@tweak1 Wrote:

Please refrain from calling the glass containers 'tubes'. Mis-stating that can be very confusing to people who don't know better. They are not tubes in the true sense of the word

I agree!

Mike

 

I have had the audions for 2 years now and just made the upgrade to the mk111 .

it took about 5 hours to settle in, best upgrade I’ve made for the money ever.  It sounds like a completely different amp.  Much better detail, soundstage, and all around musicality. I would highly recommend the upgrade, and with a 2 week trial you have nothing to lose except shipping cost.

 

 

I am waiting to see when Atma- Sphere will be tak8ng the next step up in technologies , Ralph doesnot exactly state  the module 

@audioman58 Actually I have a good number of times- we developed our own Atma-Sphere module. We are an engineering firm not a tube amp producer.

I did consider Ralph's new Class D monoblocks but I am in the UK and there is no dealer or demo available.

@rocketiii FWIW Dept.: There is a UK dealer listed on our website.

Ok Then Ralph I have heard your mono-blocks vs a class AB stereo amp 

that’s was 2x the price and a bit better in several areas That the vast majority agreed ,for the $$ monies your mono blocks are a very good deal.

when you take it to the next level vs say a very good class A amplifier , or very good class AB amps of our well known Danish companies , then myself and many others are waiting for that , look at Merrill their insane pricing ,and IMO wasted $$ on these fancy cases , a respectable look and we’ll damped chassis is more important put the $$ inside where it counts, I highly recommend using a top Furutech IEC their $75 retail being copper and gold remove Thst bottleneck judt coming in , maybe upgrading some of the filtering caps ,or putting a decent .1 poly cap on electrolytics , or Bellison  regulators which are the best , man6 ways to make this a SE type quality as well as other higher quality parts look at Silmic or other smoothing  caps .having spent over 20 years just in experimenting with the tonal balances of each caps and Electrolytics by far the worst in noise and filtering with poly caps , output caps , look at VH audio Odam caps ,even wire !Neotech Teflon 6-9s pure Copper  wire makes a difference , or Cardas Litz  wire.

I am just repeating what others too have said ,we all have opinions throw in VU meters in Australia very good ,for minimal cost .

@ghdprentice 

I had a pair of AGD’s in my system and will say they sounded good for the money. There was a bit of lack of refinement on the top end… if I remember correctly. But then I was comparing them to Audio Research Reference 160 mono blocks. I also only listened to them for an hour or so. 

Just curious, which specific AGD amp(s) did you audition? Also, which preamp was used during this time? IMO, the synergy between class D amps and preamps is probably even more important than regular class A/B component matching.

Also, one hour is really not sufficient to form an opinion about any audio gear. There have been times when I absolutely hated a piece of equipment in the first few hours, or even days, only to change my mind after further listening.

@ghdprentice 

Was using my AGD Audion MKIIs.

Actually, I now have ARC Ref 80S. Very similar to George’s Ref 160S.

And between the AGDs and the ARC I thoroughly enjoyed Ralph’s Class Ds.

The AGDs are beautiful sounding and very musical. However, Ralph’s easily surpassed them in musicality and, especially, in bass. They are much more substantial in many major ways.

At 3 times the price, the Ref 80S takes things to a new level. Contrary to Ralph’s position that the amps are now on “life support”, the tube magic of the Ref 80S makes it stand out in quite a spectacular way. Mostly, the ARC brings “life” without any need for “support”. A good example of “you get what you pay for”.

when you take it to the next level vs say a very good class A amplifier , or very good class AB amps of our well known Danish companies , then myself and many others are waiting for that , look at Merrill their insane pricing ,and IMO wasted $$ on these fancy cases , a respectable look and we’ll damped chassis is more important put the $$ inside where it counts, I highly recommend using a top Furutech IEC their $75 retail being copper and gold remove Thst bottleneck judt coming in , maybe upgrading some of the filtering caps ,or putting a decent .1 poly cap on electrolytics , or Bellison  regulators which are the best , man6 ways to make this a SE type quality as well as other higher quality parts look at Silmic or other smoothing  caps .having spent over 20 years just in experimenting with the tonal balances of each caps and Electrolytics by far the worst in noise and filtering with poly caps , output caps , look at VH audio Odam caps ,even wire !Neotech Teflon 6-9s pure Copper  wire makes a difference , or Cardas Litz  wire.

@audioman58 As you can imagine we've auditioned quite a lot over the last 45 years and we've heard them make quite a difference. But that was in tube amps with little or no feedback; when you are able to run very high amounts of feedback the circuit is able to reject these very same effects; in essence they don't win you the same thing that the did if the amp were zero feedback. Even though I knew that, it was still eye opening to actually see/hear it first hand.

@mglik One does have to be careful about the Veblen Effect. As I mentioned earlier though, the reason tube power amps are on borrowed time has to do with how class D is spreading in the musical amplifier (guitar and bass) world. Since you know about a prototype amp we sent to Ron Carter, you have a better idea than most how that works. Guitar and bass amplifiers are the bread and butter of vacuum tube producers; so its not hard to imagine where this is going in the next 10 years.

 

What’s you opinion of them say take a 6SN7 vacuum tube and use as a hybrid  ?

I see rogue doing this in a Less complex way. , I have been into modding Loudspeakers mostly myself ,but keep an open mind on the latest Class D modules 

and how to take advantage of this ,servos,and Switching is getting better and GAN transistors , how to make a better wheel ?   
how or why can Merrill try to justify over $20 k+ for their amps ,they are very good 

but  newer technologies are progressing think about how you too can make it better 

remove $$ constraints what would you add.  Look at T+A  their 200 dac for example is excellent and beats the competition at less then 1/2 it’s cost.

switch mode power supplies can in fact be better then Linear power supplies ,

they have clearly proved that .  That’s why I am waiting to hear the latest phase in

class D technologies. Moving forward, I will then make a purchase .

Thanks Mike (@mglik)… I did not realize that the ADGs you brought over were MK2. It is great you have had time with your ARC REF 80 as well as hearing my REF 160s. 
 

I look forward to hearing your Dartzeel integrated when you receive it. 

...and I'd bet they can't warm up a room...like the gud 'ol daze.....😏

"And, if one misses the weight of the old mono's, you can put them into a 'spoof chassis' of lead....."

(Just teasin....🤷‍♂️ ;)...)

 

Hi there @ghdprentice  In my system I didn’t find the Mkii Audions to lack a bit of refinement on the top end but I would say that the Mkiii GaNTubes have opened up the top end quite significantly. Last night I was listening to Talking Heads ‘Little Creatures’ on vinyl - it’s a great recording and the drums/cymbals were the most life-like I’ve heard from my system.

I had a look at the AGD website and the designer (Alberto Guerra) outlines the design improvements he has incorporated into the Mkiii tubes. I don’t understand it all but this gives a bit of insight: 

“With the new MKIII, we have extended the frequency response of the power stage, now flat up to 60KHz, and by a combination of layout improvement and the re-engineering of the output filter, we managed to also significantly increase the slew rates performances.”

 

There are many way less costly options and are too expensive for people not into high end audio (99%?) , but having heard them they sound very good and are likely to retain a niche in teh high end world for the foreseeable future. Plus the modular tube like aesthetic on the top models (despite not actually being a vaccum tibe) will appeal to tube lovers that otherwise might hesitate to leave tube amps behind, and may provide a good path for upgrades moving forward I would expect.

Don’t know about appealing to tube lovers.  Based on comments I’ve read many seem to be offended.  Personally I’ve used tubes for over 50 yrs and I think the Audion’s look pretty cool.

Myself, I grew up in the 60’s and helped customers with tube replacement working in various electronics stores back in the olden days when tube testers were still a common sight even in some drug stores.  So I have a nostalgic soft spot for tubes. THese days I am a long time  career tech guy and have come to the realization that vacuum tubes are still way cool looking and all glowey and stuff and often sound very good, but practically their time has come and gone. My reference system is 100% tubeless these days (yay!).

But I still have that nostalgic soft spot in my heart for tubes and the AGD design does float my boat by adapting a vacuum tube like aesthetic but putting much better 21st century amp technology in there. The best of both worlds for me but still only for a premium cost....

I've owned Spica's, Apt Holman, Cary (still use SLP-05), and at 65 love the weight, heat, sound and look of my Audions.  Having been in this hobby for 40 years there are a few products that change direction and I believe AGD is one of those products.   

Just ordered the new MKIII.  By the way Alberto is an overall great person and wonderful to work with.  Just saying.

Hi @testrun, I think you’re in for a treat. Give the new GaNTubes a day or two - it will be interesting to get your thoughts.

This Audion GD is just a Class D circuit stuffed into a KT88 glass envelope. It has zero relation to a real vacuum tube. A clever marketing ploy! Add some LED's for that tube-like glow and the gullible are smitten and like Jay's Iyagi proclaim it the best sounding amp ever!

Ganfets need a couple hundred hours of break in, just like any other piece .of hi fi gear.... Speakers usually don't reach their full potential until 400-500 hours are on them. The Audion is a fine piece of gear, sounds great....actually Tubey and is a little gimmicky looking...(good marketting)

 

@mbmi No GaN FET’s don’t need 100 of hours of break in. I proved this at friends home a while ago. I’d replaced an Orchard Audio Ultra Amplifier that was running for a month with one that had literally 5 minutes of burn in time. Zero difference in audio quality.

@atmasphere As usual Ralph, you are 100% bang on ! Damn & Ron Carter has one of your Amps ? Very cool.

I watched that paid for 31 minute YT of Canada Jay’s and as usual, I was blocked immediately in the comments section.

How the F can you say that the AGD Amp is the ’best" without listening to Ralph’s Amp (which I have heard on FR20’s) or listening to Leo’s Amp (which I own) or even the Underwood GaN Amps. I dragged Jay & his entourage into the Soundfield Audio/Triode Labs Cables/Orchard Audio Room back in February at the Florida show. He never bothered to once mention what he heard. This was on the Friday morning when people’s ears were fresh.

I also heard, met, and talked to Alberto & Ralph at this years Axpona where I was and even worked the Endow Audio/Orchard Audio room on the Sunday so that Leo could finally catch a break. I love Tubes and someone like Ralph is the Guy that can make a GaN FET sound identical to a Tube. Same can be said about Alberto & Leo’s designs. I haven’t listened to the Underwood, Technics, or Peachtree Amps. But if implemented correctly, they can be "magical". I’ve fooled many folks when they heard my rig and didn’t "see" the Amps.

When I told them is an all analog Class D GaN FET Amp. They were dumbfounded !

@jasonbourne71 

"This Audion AGD is just a Class D circuit stuffed into a KT88 glass envelope. It has zero relation to a real vacuum tube. A clever marketing ploy! Add some LED's for that tube-like glow and the gullible are smitten and like Jay's Iyagi proclaim it the best-sounding amp ever!"

So for the sake of the argument please help me understand the deep intrinsic meaning of your comment by allowing me to rephrase it in a more comprehensive form like this:

“….a Ferrari is just an ICE engine mounted on a metal chassis with 4 wheels, zero resemblance to a real cart pulled by real horses. A clever marketing ploy! Add a unique logo, some brilliant red color, and a thundering sound and the gullible are smitten and like someone proclaims it is the best car(t) ever.”

Is that profound truth what the comment was originally intended to convey to the vast number of your "gullible" audiophiles brothers in music?

Just kidding, and ...assuming no one actually has listened to or owns one….a Ferrari I mean of course 😉

Call me shallow but I like the LED’s and I love the fact that an upgrade takes 5 minutes to do!

@rajugsw Jay said the AGD Audion amps were the best/top two best amps he has heard.  He said he has heard over 300 amps in a “meaningful way”, whatever that means, but that’s how he came to his conclusion. If Jay hasn’t reviewed/heard the Atmasphere class D amps yet, it’s reasonable that he wouldn’t include them in his ranking.  Stereophile will not add any hifi product to their recommended components list if they haven’t reviewed the product yet.  That doesn’t mean all other hifi components are trash. Stereophile prefers to recommend what they have heard.
 

It’s in the top two best amps that Jay has “heard” thus far.  That could change once he hears the Atmasphere class D offerings.

 

@agdproduction Your post was spot on!  I don’t understand how people speak negatively about a product or a hifi tweak without trying it for themselves?

"@agdproduction Your post was spot on!  I don’t understand how people speak negatively about a product or a hifi tweak without trying it for themselves?"

 

Because it's much easier to write about something they know nothing (or very little) about than to take the time and effort to actually listen to a product!

Some people just like to argue.  What are you going to do? I've encouraged my wife to join in on these discussions many times but she says she just prefers to argue with me 🙃

There is a fine line between discussions and arguing...

The love for truth and the values and role of the arguments set the scene...

 

I cannot argue with my wife in any trivial day to day mundane matter... She is a very wise and intelligent woman and she is never "wrong" really...i dont remember being able to really fault her save on a unique subject, but she was too innocent and honest in a way to imagine such wrong doing possible by the corporate system... Then it is the only times she was wrong in his life for me...It was about the last crisis ...But i will not go further here...

She could had been  be a psychologist or a philosopher, an artist , because she was gifted,  if she was loving cerebral matter more... She is more pragmatic and on the point in any discussion  than everybody i ever meet... Discussion with her are rational and to the point and  with no back intention ( conscious one ) ...She will never discuss here with people about acoustics and gear as i did ... She "argued" with someone perhaps one time in his life on internet about a moral fundamental issue...Never again...

She stay silent ...Most of the times...

😊

I marry her the day i seduced her by lending to her one TOP books in S.-F. after the others after 5 masterpieces she invited me to a coffe and as intended by me to give me back the books ( i was devilish here)... Then i make his university  philosophical essay because she hate writing philosophical essays and she wait too late , and at the end  she was pleased by the final notation she received ...She was interrogated one hour to investigate a book plagiarism case  because the text as it was written for the teacher could not correspond to his level... Because she was more than lazy, i briefed her before the official interrogation,  one hour about it and she passed the inbvestigation in answering the teacher and investigative group of teachers... It was my best notation too at the conclusion ... She received the highest note..😊

i wrote the 25 pages text in two hours, she corrected it and submit it... But she ask me for a short course on the matter... it was about history and consciousness phases manifestations  in a university masters degree..

We marry after ...😉 It was 50 years ago...

 

Some people just like to argue. What are you going to do? I’ve encouraged my wife to join in on these discussions many times but she says she just prefers to argue with me 🙃

This Audion GD is just a Class D circuit stuffed into a KT88 glass envelope. It has zero relation to a real vacuum tube. A clever marketing ploy! Add some LED's for that tube-like glow and the gullible are smitten and like Jay's Iyagi proclaim it the best sounding amp ever!

Oh gee! We should be thankful the savior has swooped in, as always, and saved the gullible from being duped by the unscrupulous class D manufacturers. Anyone who buys anything made after 1967, with Topping being the only exception, is gullible by definition.

@mahgister  Cool story about how you seduced your wife! I had been impressing my wife with similar feats lately ... too bad she found out about ChatGPT!

I just placed an order for the new AGD Duet monos and Andante pre-amp.  I have been wanting to explore Class D for many years but hesitated because of the criticisms of the sound quality and also the feeling that Class D was still rapidly evolving.  What finally convinced me was Ralph's conclusion that his Atmasphere Class D amps were as good as his OTL tube amps, and then the outstanding reviews and the technology used in the AGD amps.  

I'll be comparing this to the Boulder 866, using a Playback Designs MPS-8 CDP/DAC and SF Electa Amator III and YG Hailey 2.2 speakers. I had been planning to wait on trying Class D until Ralph developed an integrated amp, and I still l want to compare this to the Atmasphere Class D amps and hope to do this in the future.   I need to work on my critical analysis tools so that I can say something more than "this sounds really good", and "that sounds really good too".  I'll post again if I have anything useful to say.

 

 

 

An 8 page Six Moons review?  Nice. 

 

Let me pop a few Advil up front so I can be properly medicated in order to be able to make it through and  soak it all in and I'll see you all on the other side. :^)

This Audion GD is just a Class D circuit stuffed into a KT88 glass envelope. It has zero relation to a real vacuum tube. A clever marketing ploy! 

@jasonbourne71 No, it’s absolutely not just a “clever marketing ploy.”  It’s designed that way so that when upgrades come, and one already has, the user can easily just swap the new circuit in.  That it looks cool too is just a bonus.  

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+1 soix.  Plus knowing an idiot like me could easily do the updates when available is a huge plus.