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!
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.
Showing 8 responses by atmasphere
Yeah, I have friends and customers that design semiconductors... Boiled down, a US phrase is 'the proof is in the pudding'. |
@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. |
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
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. |
@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 :) |
@badgerdms GaNFETs are designed as switching devices. To that end, they really can't be designed for audio other than to be switching power devices that happen to get used in a class D application. |
@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.
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@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.
@rocketiii FWIW Dept.: There is a UK dealer listed on our website. |