Today’s Disruptive Class-D Amps Are Changing the Audiophile Hobby Very Much For The Better

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There is a sea change going on in the audiophile hobby coming from the world of electronics – specifically via a whole crop of new-school, Class-D amplifiers. These amps are designed around any number of somewhat modern semiconductors and offer tremendous value, as well as world-class performance, all on one small, light, energy-efficient chassis. They are smaller, lighter and quite affordable, but that is only the start of the argument for using these new power amps in your audiophile system. 

The AMPED America AAP-1 stereo preamp and DAC rack mounted
The AMPED America AAP-1 stereo preamp and DAC rack mounted

Some of the companies embracing these new technologies are mainstream, ranging from Marantz to NAD to even as high as Jeff Rowland Design Group, but the main group of disruptive companies are much smaller and more organic in their approach. Peachtree Audio, Orchard AudioAMPED AmericaBuckeye Amps are just a few of the new names that are mucking it up in the new-school, Class-D amp space today. Despite the boom in audiophile gear sales during the COVID-19 lockdown, many of the more established audiophile electronics brands have lost market share recently. McIntoshhas their relationship with Best Buy that gets them into well over 200 Magnolia stores, the only way to get truly national distribution. They have also added many of the best custom installers, as well as a good number of the top hybrid AV dealers in the United States. Other brands that are more audiophile household names, such as Classe, Krell and Mark Levinson, have seen setbacks in their distribution channels in recent years. Audio Research is under new ownership again after some pretty messy bank maneuvering that left the last buyer on the outside, looking in. The new owner is well-heeled; the direction of the company isn’t fully realized at this stage of their progress but they too are part of the audiophile electronics establishment. 

Above the audiophile electronics establishment is another group of electronics companies in the Luxe Audio or Oligarch Audio category, where components like stereo preamps and DACs, as well as power amplifiers, can cost $25,000, $50,000, $100,000 or more. Some of these players are new companies and others are just new to this COVID-friendly, cost-no-object client. CH Precision, Nagra, T+A, Solution, D’Agostino, Gryphon, Linn, dCS, Wadax and more and a dozen others that sell in that 1/1000 of One-Percenter range. Are these products that much better than the establishment products or these Class-D upstarts? That depends on your taste and budget, but they definitely appeal to those in Asia who eat up all things American (or Western European, in some cases), no matter what the price. The point is that there are new players sandwiching the establishment audiophile electronics companies from the top as well as from the bottom, which never used to be the case in this hobby. 

Orchard Audio's Gallium Nitride (GaN) power amp reviewed
Orchard Audio’s Gallium Nitride (GaN) power amp reviewed

Do These New Class-D Audiophile Amps Sound That Good?

In a word – yes. They are also a bit of a mind-f**k, in that they are so small, so light, and so different-looking that they couldn’t possibly be as good as a traditional Class-AB amp, could they? With these new designs, gone are the big heat sinks. Gone are the two-man lifting requirements for a 120-pound-plus stereo amp. Gone is the need for the constant maintenance that tubes require. Gone is the heat that you get from tubes and Class-A designs. This is a brave new world for audiophile amplification indeed. 

Recently, I got a chance to do The Pepsi Challenge with a comparably-priced, somewhat higher-end GaN (Gallium Nitride) amp, versus my $5,150 reference Pass Labs XA-25 Class-A amp. The Pass Labs amp is considered to be one of Nelson Pass’ best designs. It is low gain. It is unbalanced by design, and it runs like Buster Poindexter, thus hot-hot-hot. Sonically, when comparing the two amps, it was a close match. The GaN amp had what little “sound” that the Pass Labs has (I don’t think it has much of a sound at all – perhaps slightly on the warm side, but not much). The GaN amp had every bit as much power. The GaN amp was balanced, and it could be bridged to get to 400 watts per channel. The GaN amp was physically small and thankfully ran super-cool, as compared to the Class-A amp, which is a total space heater. The prices were comparable, and the sound was comparable. I chose to stick with the Pass Labs amp, but my time with the GaN amp has got me thinking as the heat issue is a major problem in my side-by-side, eight-foot-tall Middle Atlantic Racks. I’ve got Panasonic in-ceiling “fart fans” on temperature controls to pull excess hot air into attic. The tops of both of my Middle Atlantic Racks have a drone-like array of small fans also designed to pull heat out of the rack and to the top of my converted coat closet (aka: mechanical room). 

Marantz Model 30 integrated amp reviewed by Brian Kahn
Marantz Model 30 integrated amp reviewed by Brian Kahn

Beyond GaN How Good Are These Other Class-D Amp Technologies?

Thankfully, you don’t have to spend a fortune to get into a Gallium Nitride (GaN) design these days. We’ve got a Peachtree Audio product that runs from a simple, variable output source for just over $1,000. We’ve got lower-end GaN amps also in for review from Orchard Audio that are monoblocks and really good, also for not much more than $1,000, and they can power just about anything.

But GaN isn’t the only game in town. Jeff Rowland uses a Pascal chipset in his $35,000 implementation of an uber-high-end Class-D amp. AMPED America has a $5,000 amp with 400 watts of power that is a lot of what Rowland offers (no fancy metal work) for about $5,000. We are seeing and reviewing more products using the Hypex chipset. The recently Marantz Model 30 is an integrated amp with the Hypex chipset. NAD has some Hypex options there, too. We are about to publish a review of the Buckeye Amp Hypex amp, which is also quite powerful (even compared with GaN), and has simply excellent measurements without the size, weight, heat or cost issues of amps from the recent past. 

What is the Real Benefit of These Class-D Amps for Audiophiles Worldwide?

We can talk about the benefits of size and weight, and that’s a good place to start. We’ve covered the heat and lack of maintenance issue also, which is relevant. For many modern audiophiles, having an amp that is efficient when it comes to power use is important, too. Many of these Class-D amps are 95-plus-percent efficient, meaning that they barely need any power from the wall to power up even your most demanding modern audiophile loudspeakers. Compare that to a tube amp, and you see the tube amp wasting 80 percent of its power on physical heat. Modern audiophiles don’t want to waste money or energy the way that their father’s audiophile system has always done. The problem is: can we as a hobby let go of some of the physical stereotypes for an amp, meaning that they need to be big, heavy, and rocking expensive heat sinks in order to sound their best? The truth is that we don’t need these hang-ups anymore, as technology has moved on.

The true benefit of the new group of Class-D amps is that today’s audiophile can get an amp that can perform with other, more traditional amps that cost five to 10 times the price a mere two years ago. Basically, the money that you need to get colorless, high-power, low-heat, high-output power is a lot lower, thanks to new technology.

Why Are These New Class-D Switching Amps Better Than the Ones That Came Out 20 Years Ago?

B&O’s Ice Chip sounded like its name “Icey” but for the right application, like in-wall speakers, these high-output amps were close to perfect. However, in audiophile applications, these amps were often just not quite refined enough. So, what changed? These modern chipsets are different today, and far improved, but the place where all audiophile products benefit is the power supply. Today’s Class-D switching amps (don’t call them “digital amps,” as that is a misnomer) almost always come with a beefy power supply to support these bleeding-edge new amplifier chipsets. Combining these new chip technologies with the time-tested fact that a badass power supply makes any audio component perform better is like mixing peanut butter with chocolate, as they both go well together.

Buckeye Amps Hypex NCx500 Stereo Amplifier Reviewed
Don’t be fooled by the generic look or very low price of the under $1,100 Buckeye Amps Hypex NCx500 Stereo Amplifier.

Will Traditionalist Audiophiles Fight Modern Change in the Amplifier Category?

The audiophile hobby isn’t much about embracing the future over its two generations in existence. The print magazines that have shaped the hobby for 50 years and counting put a big premium on a high price, exotic technologies, and exclusivity. These new Class-D amps are better than that, thus they represent the type of Silicon Valley “disruptive” change in technology that points many traditionalists to vinyl and tubes over more modern, more efficient audiophile electronics options. 

The next-generation audiophile is seeking performance and value, as every other enthusiast has in his or her journey over the years. The fastest way to get to an increasingly high-performance stereo system is to embrace, engage or at least understand what is possible with these types of new technologies. Do you have to own a Gallium Nitride, Pascal or Hypex chipped amp to be a new-school audiophile? Of course not, but you should know about them as they represent the types of technological advances that really can improve performance of real-world, high-end audiophile systems, while saving power and delivering excellent value. 

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Trevor

The real benefit of the latest chips from TI etc is in the Bluetooth & studio monitor speaker markets. The confined & closed space of these designs benefit from high efficiency. The latest ChiFi (Aiyima, Fosi etc) Class-D stereo amplifiers feature high grade passive parts, better heatsinking & laptop grade PSUs, all for <$100. Makes me wonder if there's a market for inline high grade capacitor banks to improve transient & bass response? Now that would be an interesting comparison, the XA-25 vs the best ChiFi?

Peter Horvath

I don’t remember heat sinks being ” synchs”
Did a robot write this story…

Postal Grunt

PS Audio is still using ICE boards in their amplifiers and appear to be able to meet the demands of their customers for quality and reliability at their respective price points.

Jerry T Snead

As an FYI I had the M1200 monos and sold them for Leos Gan Ultra amp which I feel is as good or better and no tube hiss for a win win

Ron

Great Article Jerry!

I’ve owned the Digital Audio Company 2Cherry and spent a week with the Orchard Audio Stereo Ultra 1.0 version and I can agree that these are very, very good sounding amps that most listeners would never know are class d if they weren’t told.

For those that are skeptical, Leo has his Stereo Ultra 2.0 (GaN) dual mono version “on tour” and people can sign up to be part of the tour so that they can experience the amp in their system for a week…and all it costs is the price of shipping to the next member of the tour. He requires you to be a member of Steve Hoffman Forums…but anyone interested can sign up and then message him through his website directly.

Here is a link to the tour.

https://forums.stevehoffman.tv/threads/orchard-audio-starkrimson-stereo-ultra-amp-tour.1148415/page-37

PS…I’m currently on the tour waiting and my daily driver amps include the Pass XA25 and a Wells Audio highly optioned Majestic.

Jerry T Snead

As an FYI I had the M1200 monos and sold them for Leos Gan Ultra amp which I feel is as good or better and no tube hiss for a win win

Jonathan Meyers

I find this entire discussion perplexing, perhaps only because it is not examined in sufficient depth. Please correct me if I am in error, but there are now at least five different amplifier types: tube, bipolar transistor, MOSFET, Gallium Nitride, and “Class D” (in many flavors). Moreover, these critical components are only one key element of those amplifiers. Among the others are the power supply, the input and output stages, the PCB layout, EMI shielding, etc. As a consequence, where I have ended up believing is that each amplifier is unique unto itself — its quality ultimately comes from its specific architectural design and the many electronic components employed (including capacitors, resistors, etc.). In other words, an amplifier is much more a system rather than essentially just one specific part that overwhelms everything else. Furthermore, any amplifier sounds best driving certain speakers and dismal driving others.

All of these realities lead me to conclude that the only way to truly assess the performance of an amplifier — assuming it is not carelessly designed in one or more ways — is to listen to that amplifier together with the speakers that the buyer intends to use. Instrument measurements are helpful initially, but the human ear remains the best evaluation tool.

Last edited 5 months ago by Jonathan Meyers
CrazyDave

Well, yes and no. Lots of audiophile speaker, like Wilson Audio, for example, can present a very difficult load to amplifier. Then there are Tube era vintage speakers that need a very low damping factor for the bass to be as intended. For the difficult loads, I’d want t audition carefully before I laid my money down, but for modern or transistor era vintage speakers that are easy to drive, these amps should perform at their best. Still you should make sure you have the ability to return it if it doesn’t meet your expectations. Taste is a tricky thing and de gustibus non diputandem eat.

Anthony

These amp are indeed ‘colorless’ as you pointed out, meaning: incapable of reproducing the natural harmonic content of instruments and voices. They are the “McDonalds of audio” equivalent, offering bleached sound, devoid of any excitement, sense of energy and emotional content. While they may be good for reproducing static tones for measurement purposes – for serious music reproduction they are useless but the industry surely needs novelty. All the class-d amps that were ever raved about by reviewers proved to be able only to massacre the musical message. If one doesn’t hear how much more alive and real even cheap tube and class AB amps sound in comparison to these ‘sine wave generators’ then perhaps audio was not written in his destiny…

Mark M

Enjoyable article Jerry. I am writing this as I listen to a recently completed Orchard Audio Starkrimson ultra kit. I sold mid and high end audio from the mid 80’s until around 2000. It was a lot of fun, lots of great gear and interesting people. I was always amused by the things that hobbyists would latch on to as things changed over the years. One thing is for sure, people resist Chang. Some guys were dedicated tube fans and trashed solid state at every turn. And visa versa. Digital was the same thing. Some of the vinyl guys trashing all things digital. I will agree that early digital was troublesome, but by the early 90’s both the recordings and playback equipment had become pretty solid.

I remember when class D amps came on the scene must have been around 1990. They were used in a couple of subwoofers and that was it. I didn’t understand them, but it was common knowledge that they were ok in a subwoofer, but not suitable for full range. Not in an audiophile system anyway. Then I saw them gain popularity in PA sound reenactment equipment and the products from companies like QSC sounded really good and were reliable and lightweight.

I get the establishment pushback with class D amplifiers though. For decades, for an audio amplifier to be of good quality it had to have a good power supply. That meant big power transformers, and the bigger the better. And that meant the bigger and heavier the amplifier the better. And the higher the amplifier bias, the better the sound. And there is all of the heat we associate with good sound. And along come these class D things that don’t weigh much. Don’t make enough heat to drive you out of the room and they don’t necessitate a second mortgage to buy one, how can they be any good. They fly in the face of what has been the standard for decades.

Well I have had a range of gear over the years, and all I can say is, these gan fet amps are really enjoyable. As all things audio, they have a “sound “ and it may not be for everyone, and I get that. But don’t write them off out of hand.

George Brown

Help I need a class D amp for around $1500 I’m old school 67 no wait 68 next month. Old stereo teac A-6300, HPM100 speakers, had sansui 990 damit. Planning on Klips speakers still have vinyl-+ cd’s

Jerry T Snead

Look at Buckeye amps

Gordon

Change is coming.for the best

Ralph K

Nice article!
I’ve been of the opinion that tube power amplifiers are on borrowed time for several years now. I play a class D in my home system and don’t miss my class A triode OTLs at all. The class D has the same smoothness in the mids and highs, the same engaging character (I don’t get bored of them) but seem slightly better at detail and depth, two things that the OTLs are known to rule the roost when it comes to tube amps.

Richard2139

Which amp are you using that you compare to the OTL

Oz O'Later

Dont forget Bruno Putzey & Purifi!?? THE bleeding edge designer/company in the Class-D industry and probably the best sounding?? Just saying

tom

I’m 65, a multi-intrumentalist, performer (slowing down 🙁 … & audiophile for sure but also out of necessity to a large extent 😉 I’ve owned great systems most of my life and been exposed to incredible live sound systems wether performing or as a spectator, studio systems and some real high end systems through fellow musicians, friends/acquaintances, and the industry. About two years ago I built a home theater with a Denon X8500H(A)/Processor, running 7.2.6 powering everything with external amps. L/R using VTV class D – Purifi with their integrated Tube input buffer and I was floored by the performance! Zero noise floor, dynamic, fast, organic sounding, tons of power, imaging and separation to whatever extent the source can throw at it! Ended up switching all bed-layer to VTV/Purifi. Orchard Audio was mentioned above, although I like the sound of the Denon implementation of the AKM AK4490s DACs, Like their GaN amps the same design philosophy of “audio performance” first , the Orchard Audio DAC is one of the best I’ve heard < $10K, for $500-1000!

Oaman

Hello, I follow D class amplifiers, what is your suggestion for my 803d2 speaker? I am currently using Yamaha AS 3200.

Last edited 5 months ago by Oaman
Joe Mar

I have a class D amp built by classdaudio dot com.. the sds250 and their Mini GaN 5 amp. They also go by the name Premiumaudio dot com. The SDS250 does have a heavy toridal transformer, but the GaN doesn’t. Both are plenty full of power for my Maggie’s. The strangest thing though is the sound I hear through a tube pre and a solid state pre are very similar and it wasn’t that way with an AB AMP. Anyways the Mini GaN 5 had a deeper sound stage.. for of a 3-D sound. The SDS runs cool as if it’s not on, but the GaN runs a little warm.
Wish you could try the Mini GaN 5.
Cheers,
Joe in Cebu

Ron

If you assume that amplifiers are part of a system that in the end should present music that is fun, exciting and emotionally compelling…then for some, an amplifier that adds its own sound is acceptable if the overall result is pleasing. No doubt that there are many amplifiers that “sound good” because of the 2nd and 3rd harmonic component of their output. Maybe not always, but it is likely that they are somewhat obscuring the detail and soundstage information that the ultra low distortion class d amps and Benchmark AHB2 are able to render.

But, once you hear that detail and those nuances, its hard to go back. The question is will you give this more highly detailed sound enough of a chance to really let it “sink in”?

It is not a case of better or worse…or right or wrong…it is ultimately about preferences. My own experience has been is that “quick switching” back and forth is misleading. Slow switching after listening to a song with which you are very familiar is revealing and helpful. But it is only after living with something for a week or so that you begin to get a sense of how you are connecting with the music it is presenting.

Then, maybe you still prefer an amp or other component that adds some “tone” of its own…and maybe you don’t.

phil rowland

.I bought an Amptastic class D job because a mate raved about his. Shame they are no longer in business. ‘kin excellent product.

John

Very Interesting article. From what this suggests, these new amps are transparent, although not adding nice even harmonics and subtle compression that people love the sound of from valves. So it is not entirely just a win on cost, size, weight, power consumption/waste heat by Class D.

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