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.


@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 !


"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?