New Class D amplifiers

Orchard's class d ganfet amp is the real deal- read the review in audio express. It uses post filter feedback and has a frequency response that is load invariant, meaning it doesn't change character with a speaker's varying impedance. Most well designed class d amps will be load invariant. Not so for many of those using the gan module used in the peachtree and lsa gan amps. Be careful with those as they might sound fine with speakers with a tame impedance equal to the design point but anything that varies wildly and doesn't sit nicely at the design point impedance will change character.

The best performing class d is currently coming from Hypex and Purifi. VTV, Buckeye, March, and others are selling amps at unbelievable pricing using these amp modules.

FWIW, a friend brought over his two class D amps (Peachtree stereo and Atma monos) to compare to my two class A amps (Reference Line Silver and modded Plinius SA103). The class A was better in virtually every way. He was disappointed and sold his amps. I was also disappointed because I like the idea of a light amp that uses little power, and was willing to switch if it sounded as good. But the trade-off is too great for me--and for him. He also has the 25-watt Pass class A. Nice thing about the Plinius is that it idles in A/B and you can switch to A when you want to listen.

Digital Amplifier Company made some great class D gear. It's a shame Tommy isn't around any longer. I loved the Cherry amps I had. I haven't seen anyone mention D-Sonic and I am curious why. I like the D-sonic amps I have heard with a Tube stage in front of them. Are D-Sonic amps behind the times or where do they stack up on the Class D ladder?

I have owned the Cherry amps (both the stereo and the monoblocks) and the Atma-Sphere monoblocks - I thought both were outstanding Class D amps. I now own a D-Sonic stereo amp which IMO rivals both of the above. The Cherrys are gone for obvious reasons and I sold the Atma-Spheres once I heard the D-Sonics which are about half the price. I can't say the D-Sonics were better, but to me they sounded as good and at half the price they were a much better value in my system

Having owned the 2Cherry, which at the time sounded better than a number of other amps I had owned/auditioned...I would say that the Starkcrimison Stereo Ultra improves upon the 2Cherry in that it has both a more detailed and a more powerful low end.

At the end of the day, all we can do as enthusiasts is try products that seem to be getting a good buzz and see if they are compelling in our own systems...and then if so, decide whether to make a change.

I’m a tube head and never warmed to many Class D amps. But, as time went on and I heard more Class D offerings that and began to find them sonically appealing.

About a year ago, I bought a "summer amp" to substitute in for my tube amps during the heat of the summer. I tried a Ken Ishiwata voiced Marantz reference Ruby integrated. It sounds as good as several of my tube amps, and better than a few well known names. It doesn’t beat my 48 watt SET 805 Class A amp, but it’s really, really, good. I hate to list the tube amps that the Marantz beat in my system.

I think the key to Class D is voicing by the designer. I’ve tried several other Class D amps that sounded a bit too dry and lacked warmth and life.

@wrm57, I just sold my Pass XA30.8 after purchasing the AtmaSphere Monos.  I like a few things better with each amp, and more than not I find they sounded pretty similar.  Of all the other SS amps I've tried against my Pass amps I find the AtmaSphere the closest in terms of smoothness, warmth, and lack of fatigue.

In the end, two 14 pound boxes and zero heat swayed the decision...  Packaging and shipping the Pass (106 pounds boxed and that is the baby of the family) was not fun :)

@ddafoe , glad you found the Atmas to your taste. No doubt your back and energy bill will be as happy as your ears. Smooth and warm are the characteristics I most recall from my brief time with them, which left me wanting more air and sparkle. But that’s my ears, my system, of course.

I'm in the Hypex and Purifi camp, Bruno Putzeys is a wizard.  I have the March Audio P502 and it's been a high wattage wonder in driving my inefficient Maggies and Vandies.  Wonderful detail and clarity, and driving bass to get the toes tapping and the emotions rolling.  Dead silent, no noise whatsoever.  March has gone all Purifi, can't go wrong there, currently I would get the P422 stereo power amp.  Love the compact chassis, build quality and efficiency.  IME separates are nicer than an integrated, just got the Topping Pre90 not too long ago and that's all the pre you'll ever need, wonderful relay-based volume control, a bargain, and the drive of all balanced connections is great.  Alternatives to March are Audiophonics and VTV, who offer Hypex and Purifi based amps.

 I most recall from my brief time with them, which left me wanting more air and sparkle. But that’s my ears, my system, of course.

@wrm57, yea that is one of the differences I heard between the AtmaSphere and the XA30.8.   I found the Pass to offer a little more detail/resolution, or at least present things in a more forward way compared to the AtmaSphere.   In the high frequencies I did find my Pass offered more 'sparkle' and maybe more finesse in the small details overall.   With a handful of other amps I've compared with either a X250.8 or XA30.8 it was always the other amps offering a little more detail over the Pass, so its strange for me to hear a solid state amp that presents a more laid back presentation than the Pass.   AtmaSphere does specialize in tube amps after all :) 

I switched between both amps a few times and its not like the general details are missing, its just they are more detailed and noticeable with the Pass, where the AtmaSphere seems to paint the overall sound with a wider brush and maybe has a little more color/fullness (think meat-on-the-bones) sound.    My speakers are pretty detailed and not forgiving at all so I can live with the few rows back sound.   

I found the AtmaSphere to offer a blacker background, way better bass, and excellent imaging, along with a very similar sound signature to the Pass.

Being the Pass is now $7100 I think the AtmaSphere Monos like most good amps I've compared to the XA30.8 (some more and some less expensive) are all in the same league, its just more personal taste/system matching.   At this point to my ears at least, it is no longer the Class A design just beats the Class D design, its more of a what sound signature and attributes am I looking for...   Compared to my first Class D amp I tried back in the early 2000s, that is a big step forward as the XA30.8 is great sounding amp!

I have a Legacy Audio system. 7.4

The last component added was my Legacy Class D V:2 and V:5 Amps. Previously I had ATI Signature series 6007 Top of the line. ATI was noisy, hot and solid as a rock. These Legacys are dead quiet, cool as a cucumber and just as solid. If there is warmth difference, I can’t tell it. I love them. Best move I’ve made.

I have AGD Gran Vivace arriving tomorrow or early next week. I am super stoked because I already know they have terrific synergy with my speakers. I will reply with my early findings.

This was mentioned earlier in this thread, and in the forum, but I thought I'd post a link here, because it may be of interest in this topic. 

I have one of these being delivered today. I plan on trying it with a Bluesound Node and a pair of Ohm Walsh 1000's, which are also on order. My current system consists of McIntosh preamp, Bryston 4B3 amp, and Maggie 3.7i's, and analog & digital sources. The new stuff will be a secondary system, but it will be an interesting comparison.

Harley of Pearl acoustics- the British YouTuber- dropped a video yesterday that  outlined the status of Class D today very well I thought. Some explanations were new and enlightening. I suggest anyone wanting to learn about the best way to go have a watch.

People who I respect for their experience and knowledge either own Ralph's product- I too am hoping for an INT from him someday- or they spent less and bought the Orchard Audio gear. The two mini mono's they make are cute as bugs ear hanging in mid air from the speaker binding posts. 

Somehow at this point I see the new Class D Ganfet amps best use for bass power. Very soon that may change but for now I'll keep the Pass gear.

I just bought D-Sonic ma3 3000s 1500 watts per channel at 8 ohms.  I have only just got them but the background noise is silent.  Black.  Can't hear a thing.  I have only had them on for 2-3 hours so far but I think they sound very nice.  I bought D-Sonic 11 channel amp also 400 w per channel for my home theater room to try.  Wiring it up this weekend.  Mytek Audio has a monoblock ganfet technology at 10K a pop that I am going to try when they are ready (soon).  I  have the Mytek Empire Network Streamer with Roon core and it is unbelievable.  The best music I have ever heard in my life through Von Schweikert towers.  You have to work full time and spend every penny in this hobby and then and only then will you not have nearly all fo what you want LOL

 

@thewetdog59 

 

You have a great system!  Really interested in how you think the Gan1/BS Node compares to your Mac/Bryston system you have.  The Maggie 3.7i are Great speakers.

Thanks everybody, Lots of great suggestions here.   i've compiled a list below of the Class D equipment that seems most appropriate for me to pursue.  Many of those suggested seemed like slam dunks as I read about them further, but I must consider things like integrated or not which is a factor for me, I'm leery of getting three pieces equipment versus one.   

 The fun part of course is researching to see what's best!  I will no doubt be selecting one of the amps below.  

 in no particular order.

 

 

     

The two preeminent digital audio gurus of our time are Bruno Putzeys of Mola Mola fame and Peter Lyngdorf. They’re actually friends and have collaborated. Take a look at their amps. Lyngdorf makes a few that include RoomPerfect, the greatest room correction software ever invented. Mola Mola offers small footprint mono blocks that are said to rival the very best Pass Labs amp costing 100k. Their mono blocks are 17k. 

@grantgg that's a pretty BIG list! What's your plan to narrow your choices? Price? Form factor?

krell_fan1

Yes my Lyngdorf MP-40 is probably my last processor. I think it does about as good as I'm goona get. Love it's over the top adjustability and more importantly its sound. Just killer ...

+1 to Wyred4Sound IcePower class D amps. I have the ST500, which I bought used. It sounds at least as good as any solid state amp I've had. Just as important, it doesn't have thin/parched harmonics, dry treble, or that soulless "accuracy" class D is sometimes accused of.

There's an ST1000 F.S. by a Canadian seller on the other audio site that matters. Cheap money and a low-risk way to dip a toe in class D.

I did the tour with the Orchard Audio Starkrimson Stereo Ultra and had it in my system for about 9 days. It’s a fantastic amp — dynamic, great bass, good soundstage. It was better in many ways than my Belles Aria monoblocks but not enough to make me want to switch. I also spent a day listening to the Atmasphere Class D monoblocks. Also fantastic amps but felt that the Aria monoblocks were a little more dynamic and transparent. I feel like class A/B amps still have the edge but getting to be almost indistinguishable between the two.

Check these-out for around $5k  really good Atma- sphere

http://www.atma-sphere.com/en/classD.html

If the AGD Audions are too pricey you should consider their Tempo stereo amp that probably offers a good bit of the Audions for a lot less, and like the Audions the Tempo is upgradeable as technology advances, which I view as a huge plus.  Best of luck. 

The Atmasphere class d amps currently retails at $5500. 

Aren't many of the newer Jeff Rowland Design Group amplifiers Class D?
I haven't visited their website or products for some time but while very spendy I always had the greatest admiration of how uncompromising his designs were.
And not to mention perhaps the most gorgeous looking products ever made. 

AGD-- “There Is No Substitute”

@soix I had overlooked the AGD Tempos.  look pretty tempting. 

So had I. Anybody has a ballpark price for AGD Tempos?

Price for the Tempo direct from AGD is $5500. Only a couple of dealers listed for the US. Don’t know if you can get a discount from one of them, or not.

@erik_squires 48 hours on to sound best for probably the  same reason I leave my pre and CDP on 24/7. They run so cool it takes forever for them to warmup and sound their best. Since I leave them on all the time I turn off and unplug for about 30 seconds once a month. Seems to be beneficial.

The sound signature of your system comes mainly from your pre-amp....Go Tube pre with a good class D GANFET amp and you’ll love what comes out.

@grantgg: I am surprised that neither you, in your quite lengthy list of Class-D amps (including integrated models), nor has anyone else contributing to this forum’s thus-far two pages of discussion on this topic, mentioned the now quite widely advertised HiFi Rose RA180 integrated amplifier. which is admittedly a rather unusual-looking piece of Class-D audio equipment with its gear-driven volume control and other SteamPunk-like features (some liken its appearance to the high-end Swiss manufacturer Nagra’s equipment).

This Seoul, South Korea-based company claims that it is using a new variety of solid-state transistors, gallium nitride (GaN) FET transistors in place of the standard silicon ones, which for technical reasons are claimed to greatly improve the sound of traditional Class-D amplifiers, which suffer from time-delay problems associated with using silicon-based transistors.

Julie Mullins of Stereophile Magazine published a review of the HiFi Rose RA180 integrated amplifier on December 2, 2022 - take a look at her in-depth review here: HiFi Rose RA180 integrated amplifier | Stereophile.com.

I’m surprised no one else posting here has mentioned this particular integrated amp, which is quite feature-laden, including its ability to drive biamplifed speakers.

You will get all kind of opinions but bottom line is you have to try it and see if a class d amp works for you. It has for me for many years and I have heard it all at shows, dealers. Etc. Everyone has a spin. Bottom line is class d is as viable as anything and in many cases more affordable. Not to mention more efficient, generally smaller and easy to deal with. Only you can decide. I can only recommend you do.

I “downsized” to a Cambridge Evo 150 (Hypex based) recently based on positive press and glad I did. Read the readily available info and reviews. No BS there. It sounds and works exactly as advertised. Good luck deciding! So many good ways to go with Class D these days. It’s a better time than ever to be an audiophile !

I had a listening session with a friend just yesterday!  Pure bliss!   Couldn’t ask for more.   

 

This Seoul, South Korea-based company claims that it is using a new variety of solid-state transistors, gallium nitride (GaN) FET transistors in place of the standard silicon ones, which for technical reasons are claimed to greatly improve the sound of traditional Class-D amplifiers, which suffer from time-delay problems associated with using silicon-based transistors.

A solution in search of a problem. The best performing class d amps on the market today do not use GaN fets.

 

Go Tube pre with a good class D GANFET amp and you’ll love what comes out.

 

 

If you like tubes. If you prefer to preserve the integrity of the input signal, I would avoid introducing tubes into the signal chain.

 

@kuribo: Then, how do you account for why gallium nitride (GaN) FET transistors are being touted as "all the rage" among afficionados of Class-D amplifiers these days (witness the Stereophile review of the HiFi Rose RA180)?

Could you please cite one or more examples of those class-D amplifiers which you say are the "best performing class d amps on the market," and if possible, describe what kinds of silicon-based devices and/or alternative technologies their manufacturers are using instead. Thank you!

@erictal4075  have seen Rose but wasn't aware it was Class D.  Thought they were streaming Don't really care for steampunk look.

@tommylion 

Thanks for the input. Somehow Google didn't return a hit. At $5500 the AGD Tempos are at the same price as the Atmasphere, and on an earlier post @mglik mentioned his experience with the more expensive Audions vs Atmas as being different flavor rather than better/worse. This might suggest that at the same price point the Atmas might be better performers - but this of course is just pure speculation on my part.

As more units hit the market, I'm looking forward to getting more opinions about the GaN amps that take digital in and get a flavor if this elegant solution can be sonically on par with much more expensive implementations.

@erictal4075

See Bruno Putzey’s comments regarding GaN devices usage here:
 

As for better performing amps, see the new Hypex NCx, nilai500 and the Purifi amp modules.

GaN is the flavor of the day. Most of the amps using it are leaning on the marketing and claims of "new and improved". It’s only an improvement if you are clever enough to implement it in a way that exploits its advantages over traditional silicon and so far few are actually accomplishing that. In fact, many GaN amplifiers out, from Peachtree and LSA for example, use old class d designs without post filter feedback, resulting in load dependent frequency response. Most modern class d amps have post filter feedback and flat frequency response with load. Performance wise, load dependent response is a step backwards.

No rational reason whatsoever, from a performance standpoint, to spend $5000 and more for a class d amp. Of course if someone wants to spend $4000 for a flashy case to get performance that can be beaten by a $1000 Hypex or Purifi amp, it's their money to squander...

The advantage that GaNFETs have is they have very low parasitic inductance. What this means is its easier to build a module that is low noise- and by noise, I mean the kind that radiates from the module over the air and thru the AC power. Its important to keep switching noise and parasitic noise low because it can mess with other gear and affect its performance. As an example, our class D amp makes less noise on the AC line than most tube amps. In terms of noise that it makes in the loudspeaker itself, 90% of that comes from the input buffer circuit, but even then is obviously quieter than tube amplifiers (I use horns at home FWIW).

We've been docked a bit on account of the cost of our class D (which is cheaper than most of our tube products). We built it to be rugged (so it will ship without damage), to last decades, to be easily repaired and updated and to that end it has a fairly expensive chassis and power supply. It would actually be more expensive if we used someone else's module.

 

to last decades, to be easily repaired and updated

Does anyone actually think anyone will be using the same class d amp in 20-30 years? With the way the technology is still evolving, I find that bordering on pure fantasy. I see no reason why having something that is easily repaired (what can be easier than swapping out a module?) or updated should add significantly to the price.

Linear power supplies are have for the most part been superseded by smps. With all the class d amps on the market using smps successfully for a decade or two now, there is enough data to show they are in general reliable and that their performance is more than satisfactory. But then, nothing says quality like a big, heavy transformer and flashy expensive case, especially to those who are willing to pay a premium for racing stripes and metallic paint. Vrooom!

All I can say is I remember when a certain member of this forum would simply not leave anyone who liked Class D alone, and insisted that Class D would finally get listenable with GaN. 

Hahahahaha.

Don't get me wrong, I'm all for technological improvements, but I see more clear innovation and utility in Atmasphere's amps than in doing the same old thing with GaN (apologies to you Technics fans!)

GaN is good check out Wolfspeed.  If you are really interested in ADG, I own Audios deal with Alberto the designer.  Great guy.  He will respond to questions, interest on the ADG web site. 

I see more clear innovation and utility in Atmasphere's amps

 

For example?

@drhamp ,

 

The Cherrys are gone for obvious reasons 

It's not that obvious...

@jcarcopo

 

I do not understand what you are talking about.

In my area the voltage swing around 122 v.

But I had never noticed any problem with Starkrimson Ultra for 8 days.

 

I can not tell which of Atma, Audion, Starkrimson will work better with my speaker yet.

 

But if you are curious about Class D amp, just be in line for tour of Starkrimson.

If there are local dealer of Audion, Atma, I will be happy to do home audition for 2-3 days, but no dealer of them aroung Seattle area.

 

Thomas

Anyone also told they need a Variac for it to work?
 

@jcarcopo  I don’t quite understand your post.  What happened with your Ultra?  I used the Ultra for 2 weeks and had zero issues. I thought it was a great sounding amp.  It was not the dual mono version, though, but there are at least a couple of dual mono owners on another forum that are very happy with their amps.  Are you saying that you can’t just plug it into the wall and use it?  I’ve also exchanged a few emails with Leo and he was pretty responsive and helpful, so kind of surprised at your comments.