Competitive class D amp suggestions

DH ( Mark Levinson ) ...if ML is expensive - you can pay attention to it

http://www.bantamone.com/

@ ricevs Thank you, yes they sound pretty well...and yes Thank you again, I am happy with what I have created. It is a modern good looking "Tube", never said it needed "vacuum" to work....and as you know, we are not trying to convince anyone with words. This is a matter of listening.

Once upon a time, there was an Italian scientist who wanted to convince people that Earth rotates around Sun. It was just a matter of watching, but people didn’t want to watch using his "gimmick", which happened to be... a tube too!

Have a nice day.

We are going to the audio show in Munich. Hope to see you there so you too may convert to the CLASS-AGD ;)

Ciao and all the best

Yes, the GaNtube is done for marketing and is indeed a "fake tube". Everyone knows you could have put the circuit on plug in boards inside a chassis that you could also upgrade easily.....you just take off the cover and change the circuit boards.....but no, you decided to make it look like a tube amp by mounting the class D circuit inside a tube body. Nothing wrong with that......but it is for show only.....yes, you can upgrade slightly faster......but at increased cost to the consumer. Plug in boards on a main circuit board would be cheaper.

A Vacuum tube is a Vacuum chamber that " is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied." Your Tube is not a vacuum tube.....it is a solid state circuit inside a tube body.....therefore it is a fake tube.....it is not a Vacuum tube....it is pure marketing. Just admit it.....you did it for the "cool factor". Nothing wrong with cool factor.....some people will buy it just for its looks....good for you.....making money is good.....and you have a great sounding amp.....with fake tubes.....he he.

May you be happy and sell a ton of fake tube amps.......

Interesting. 

How is the PS Audio Gear?

I had S300 for several years.  Sounded great.  Ran cool and powerful for a $1.5K amp. Not ever a problem.   Only sold it to try class A/B as I had always ran D.  Might try the mono blocks someday. 

Have a listen to the Elac Alchemy amps. Class A input stage with class D output. They were sounding waaaaay above their price point at Axpona.

How is the PS Audio Gear? 

PS Audio is now having a sale on all their class D amps.    Pickup a couple M700 mono blocks for little over $2K. 

Atmasphere class d amps can also be interesting. I did not find them on the site and have no idea on preferences made in their design. Neither i know if there are already completed models. Can Ralph provide  more detail? 

I can. Its been the most successful product entry we've ever had. We started shipping last June. We didn't put up the product page until about 2 months ago. Early on the project (about 5 years ago) we had a prototype that demonstrated that the idea was worth pursuit- and that a class D amp need not have any audibly objectionable characteristics.

The simple fact is most output sections in traditional amps have distortion product based directly on their linearity. And since the output devices are not all that linear, feedback has to be applied to make them look better on paper. That's been a problem in solid state amplifier design since the inception of solid state. Class D does not deal with that problem, since the output section does not rely on linearity at all- it switches. So the distortion generated has entirely different sources!

One problem in traditional designs is getting enough gain and bandwidth to support the amount of feedback used. Traditionally this has meant that the feedback at 100Hz is quite a bit different from what it might be at 3KHz or 7KHz and as a result brightness and harshness has been present (put another way, if there isn't sufficient gain and bandwidth in the circuit, the feedback will decrease with increased frequency).

We've all heard this over the last 60 years of solid state amps; brightness and harshness is for many one of the worst failings of any audio system!

Class D offers a way around that, by allowing for profound amounts of feedback that is very difficult to do even with modern devices in AB circuits! With such high amounts of feedback its possible to build an amp that is both low in distortion while relaxed and detailed better than the best tube amps. To some this last statement might seem a bit weird but the experience of amps with low distortion not sounding all that good is common. At this point (and take this from someone who has been at this over 50 years) I'm very convinced that tube power amps are on borrowed time.

I play a set of our class D amps at home if that tells you anything.

It seems it is about time to clarify a few things for the benefit of all my fellow audiophiles and customers.

The GanTubes are not “fake tubes”, they simply are not Thermionic Tubes, the same as a LED Lamp is not a “fake bulb”, it is simply not a filament-based bulb.

In some of the comments, there is a statement that says: that “GaNTube” is just “marketing.

Well, I beg to differ, it is much more than marketing!

There is a lot of engineering and a lot of interesting solutions to deliver a great sound, and much more added value to all the Audiophiles (btw…have you ever tried to put a model of a boat inside a bottle? Do you think it is so easy? 😊)

Let me ask a simple question:  where can you find another example of a Hi-End Audio amplifier that can be upgraded in less than 10sec without the use of a screwdriver or any other tool for that matter, and without any risk of electrocuting the user? (Yes…rule #1 in marketing is never ever killing the customer 😉).

A “fake tube” with an octal socket?! Well, the octal socket we use is a standard socket that has been continuously used since the 1930s… the standard socket of any bulb, (LED or Filament based) is around for even longer. They both are the same as they were when they hit the market…100years ago. 

I think we can agree that if they had not been reliable as an electromechanical part, they would not be around anymore…after 100 years.

GaN technology and related product roadmaps are still at a very early stage compared to one of the silicon-based components (70years of development). So to us, the possibility to offer an easy and simple way to “upgrade the sound” by swapping a new “Tube” containing a more advanced version of the GaN Mosfet (or a more advanced design of the power stage), while preserving the value of the object (the amplifier) in time, is not a trivial thing.

With the GaNTube platform, we offer that value; in fact, we already introduced in early 2021 the MKII GanTube version for the Audion and the Vivace. Thanks to the upgrade now they are switching at 800kHz and can deliver 200W and 250W (up from 170W and 200W/4ohm respectively).

The AGD Tempo is designed with the same principle of upgradability, but with far less simplicity in the operation. The AGD Tempo idea was conceived with the idea to deliver a lower entry point price to the technology, in a very compact housing and retain as much as possible all the sound characteristics of its bigger siblings.

The AGD Tempo is not technically a Dual Mono, the 2 channels share a common main power supply (larger but single).

I am sure you know that regardless of the definition of dual mono, and design of a 2-channel amplifier housed in a single chassis will always have some level of influence in the sound stage, that is due to the magnetic induction generated by the flow of high current in one channel picked up by the other channel, and vice versa.

However, from the layout point of view, the AGD Tempo has been designed in a way to minimize this effect, with reduced stray inductances and opposite direction routings (where feasible), but physics is physics…

The Audion and the Tempo are very similar in all aspects of the sound stage, depth width, and the holographic effects that all AGD GaNTube and GaNPower Class-D amps (well better to call them Class-AGD 😉) are getting famous for, and of course for their technical specs. They both share the same identical components and circuitry.

If you have the opportunity, please read the review from Rick Becker on “Enjoy the Music”, he landed to the same conclusion. https://enjoythemusic.com/magazine/equipment/1221/AGD_Tempo_di_GaN_Stereo_Amplifier_Review.htm

Of course, it is impossible for me to choose which is the better between my 2 babies, I am a true proud parent!

So again, thank you for the opportunity to clarify some of the points brought forward in this thread, and call me/write for any further questions or any help.

https://www.ap.com/blog/thd-and-thdn-similar-but-not-the-same/

@rsf507 thanks for the link. I have a bit better idea about Atmasphere amps than before. I may also ask by email. As to the distortion, I don't know what THD really means. As noted in this thread, my class A tube SET amp with THD 0.5 gives notably cleaner sound reproduction than my class D amp with THD of 0.001. 

@mbmi

For high efficient speakers the Mono blocks and for medium to lower efficient speakers , get the Ultra Starkrimson ...according to Leo at Orchard Audio.... And he always answers the phone....

That is the general recommendation, but if you really want to figure it out properly then please see my blog post here:
https://orchardaudio.com/2022/03/22/how-much-amplifier-power-do-i-need/

@niodari the Atmasphere amps are listed on their website here http://www.atma-sphere.com/en/classD.html

They are completed and from what my dealer has said there are already 2 runs that have been shipped. Although there are very few who have talked about their experience with them. Maybe they are to busy listening 🎶 

Then it seems that i have no clear idea on what the "hybrid" actually means and how it is implemented. How GaN output is "packed with tubes", just for an additional flavor or for an additional power? Which architecture is "preferable", hybrid or this one? I have no idea how AGD amplifiers sound, but in general i prefer as less flavor as possible. 

Atmasphere class d amps can also be interesting. I did not find them on the site and have no idea on preferences made in their design. Neither i know if there are already completed models. Can Ralph provide  more detail? 

@niodari the AGD amps are not hybrids, they are Class D using GaN devices for output packaged in a "tube". Check them out on there website.

Anyone compare the new Atmasphere class d amps to any other class d? I know it's new but my dealer says Atmasphere is working on their 3rd run of these amps. Atmasphere claims the distortion is a LOT lower than even their OTL amps.

Thanks everybody for your comments and passion to class D amps, a challenging alternative way of sound reproduction. 

Analyzing your suggestions, if i am not mistaken, Jeff Rowland Model 125 is ICE Powered. Since I already had an ICE Powered amp, this might not be an attractive option for  me (given that this amp not cheap, perhaps just good-looking). 

Peachtree GAN 400 can be an interesting choice. I have emailed them a few days ago, did not get an answer (not a nice way to "answer" questions). Then i called them. They say that  they do not ship outside US or something similar (a bit inflexible answer, i would say). Orchard Audio GaN mono blocks is an alternative  (also less expensive) option . I just emailed them. 

As to Rogue Hydra and Dragon amps, Hydra's power would be fine for me unless Dragon sounds different. Somebody mentioned AGD Audion monoblocks. Both, Rogue and ADG are hybrid, AGD is about twice more expensive and twice or more times lighter, do they sound better? 

Honestly, I am not too convinced with an idea to combine tubes with SS in one unit. If I want tubes, I go and listen to my tube amps. 

My homework turns out to be not easy -  I may end up with buying nothing.  

Anyways, your further inputs and highly appreciated!

for you to say that the peachtree is far behind the purifi is kinda ridiculous - this has not been my experience - at least compared to the nad purifi. i thought what sounds better in the long term  - is the most important criteria - 

Jeff Rowland Model 125. A friend just purchased a pair for his Maggie's and loves them.

Try Martin Logan Forte. Such an amazing tool and amplifier.

For high efficient speakers the Mono blocks and for medium to lower efficient speakers , get the Ultra Starkrimson ...according to Leo at Orchard Audio....  And he always answers the phone....

For $1600 get the Orchard Audio GAN mono blocks...TAS budget product of the Year....For $3500 get the Jeff Roland GAN amp....Both fantastic use of the new GAN Technology. 

Purifi and Orchard Audio have both gotten stellar reviews, which isn't surprising based on their best in class d measured performance and state of the art designs. They are your best bets. Peachtree uses a load dependent design and a low switching frequency which does nothing to exploit the benefits of GaN tech. Their design is far behind Purifi and more akin to Tripath and their tech from 20 years or more ago. They just use the GaN devices as a marketing technique. You can do better.

Also try different and better AC power cords. My only experience with class D was with older Bel Canto ref500m, thought they were so-so until I upgraded the PCs to DH audio red wave with furutech plugs, result was much better. I’ve heard the newer Bel cantos like ref600m are better still, you might take a look, but I’m leaning GAN design for cleaner treble and better imaging. There's no contest when you look at 10kHz square waves or treble THD. I’m still happily using class AB ML 532h. The atmosphere class d got a favorable mention in a trade show review recently. Benchmark AHB isn’t class D but might also interest you, and 30 day money back. Good luck and please tell us what you tried and selected.

check this out

DA&T K422 Bi Amplifier

checkout creek audio,, fantastic sound. cant go wrong

Orchard Audio KingKrimson Ultra.

They use GaN FETS and hence have almost  immeasurably low THD & noise.

@niodari 

The UcDs were DIY amps that I build over 10 yrs ago.  Ncore via Teac, NAD, and Cambridge designs.   Purifi via Mivera.

I have always found that the source content really defined the listening experience. Garbage in...garbage out.

Never listened to vinyl and relied on CDs before streaming.  Had high end Levinson transports, class A amps.  Doesn't compare to streaming native content that I'm experiencing now.

I have to say that my old UcD 700 monoblocks sound really good through my Roon core and streaming via Qobuz.  The Purifi's are a good step above and my current reference.  The Class D GaN 5 gives me another level of definition.  I can't really describe it (and not going to throw out all the reviewers terms).  It just has me saying, I've listened to this song 1000 times and wow, it really sounds so much better.  If I had to use one word....layering.  Not 3D, but something special.

Looking forward to the Peachtree stuff and will also be trying the Rose RA180 when it hits the US. 

Do you mean any particular JR class d amp?

As to Nuprime, i am not aware about STA 9 but still have HPA 9 preamp which is class a. Quite well sounding preamp by the way.

Besides the ones I already mentioned, Jeff Rowland is another egregious omission.

Check ATI 500 series they have some

great class D amps 

also mono price has a couple back ordered till December 

I have had more than a few amps in my 2 systems over the last 20 years. The one class D amp that I remember was a PS Audio--dont remember the model number. great sounding amp.. Fast forward to probably just last year. I picked up a NuPrime. sta-6 (discontinued ) The STA-9 is current offering. The STA-6 has a class a pre stage in it with class D output. It does get a bit warm. Certainly not your typical class D amp. I am really surprised at how good it sounds. Ive pared down and in my main system there is only one other choice for amplification a Bottlehead Kaiju.. and have to run the BH on a different pair of speakers with high sensitivity.. The NuPrime STA-6 cost. 449.. not bad surprising punch way above its price point. I think buying a pair of the Wharfedale  EVO 4.3 on a whim and wanted to see what this   dome mid range  is all about  --not many designs use dome mid.   it just happened that this amp really likes the Wharfedales.  

I run AGD Audion mono blocks. They are destination amps for me.

For decades, I was a die hard SET guy. Was always turned away from SS because of the SS glare or edge. Not a problem with the AGDs. And the lack of distortion is a game changer.

Knowing Ralph, bet his new Atma Class D mono blocks are also excellent. 
Not Class D but an innovative design, Bakoon also give a clear window with no objectionable colorations. I have their headphone amp. Easily replaced a Berning ZOTL.

+1 on the Rogue Dragon, have owned 2 and the Medusa that proceeded it. Fantastic, versatile amp that really sang for me using Telefunken's.

I have heard the Rogue Sphinx many times at a local dealer. Every pair of speakers has sounded good with it. I have a Peachtree amp 500 Driving a pair of Focal 1028BE speakers. I am very happy with the combination. I understand that the GAN 400 is better, but there are very good deals on the 500. If you can still find one…

Thanks again for the input. 

Based on your suggestions, current possible selections are (in the priority order)

Peachtree Gan400, March audio P262 (which indeed seems to be well built - just judging by photos), VTV Purifi, and i may check the other suggested options as well.

Thanks @twoleftears for your comment. Though my question could not be so stupid; e.g., it is a common point of view that Ice Power amps sound natural and less analytical then many class D amps. But of course, this does not classify them as the best class D amps.

@smargo, your explanation was very useful, especially when you compare three amps with different type of modules in a comprehensible may. I also owned Cherry desktop Maraschino (STM). Its main attraction is the size (and power it gives for that size). I think the AGD amps somehow borrowed the desktop concept of STM, at least, in the design. The Megaschino is considerably better (and also it costs about 5 times more i think).  

Give the Peachtree Gan400 a shot. You won’t be disappointed. 

@niodari It's all about the implementation.  Asking that last question is like asking how different bipolars, jfets and mosfets sound.

"how would you characterize, roughly, sonic differences between Ncore, Purifi and GaN amps ? Why you decided to try Peachtree 400 if you already had another GaN module amp? "

My Peachtree Gan sells  for $3000 - My Nad amp is purifi at $1,999 - I previously had the cherry desktop version "stereo amp" - In my opinion - the peachtree is the more sophisticated sound of the 3 - More grown up - More high end - The nad is good sounding as well - the cherry amp - id have to place 3rd - and if you didnt know any better - you would think the cherry and nad are fine and dandy.

The Nad sounds very good to me  The nad tries to be high end - but it is not - its more of "im the nad and i use purifi and i sound good - im here and why would you think there is something better then me

But the peachtree doesnt care what you think - its the older brother - with more of sophistication to its sound. again i have said it a thousand times but the peachtree is definitely the "high end" one - its very subtle and very clear and you dont get wowed by it - but its the more long term sound you can live with - without having the need so much to see whats even better still

I can't imagine what amp could replace my Voyager. I still have the EVS1200, to try as a subwoofer amp, unless someone wants to buy it

@embolek, how would you characterize, roughly, sonic differences between Ncore, Purifi and GaN amps ? Why you decided to try Peachtree 400 if you already had another GaN module amp? 

@tweak1 , did you sell the Voyager, why, did you get a better class D amp? 

I have the Rogue Sphinx V3 and really like it. Agree with the previous poster who noted that tube rolling does help to beef up the overall sound but at the price it's an impressive amp. 

Underwood HiFi has 2 that have gotten excellent reviews

Warp 1 @ $1200

Voyager GaN 350 @ $3000

I have owned the Voyger for almost 1.5 years. Truly an amazing bargain

@avanti1960  where did you hear the Rose RA180?  Here is the US?

I've been very happy with Class D for quite some time.  Early Hypex (UcD, Ncore), more recently Purifi and now Class D Audio Mini GaN 5.

Will be trying out the Peachtree 400 and their GaN1 in the near term.

Lots of options...

I am very happy with D-Sonic M3a-600M mono blocks powering my ATC Scm19's.  

I think the Belcanto is Class D

Listened to a couple different Class D amps last year from Rogue. I thought they were ok played thru Gallo and Dali speakers. I found both models a little bright. I actually enjoyed the CM3 more which is a tube integrated though not particularly tubish in presentation. I would be interested in hearing more D amps but until my ears signed off I would be loath to put down my money. I will say the Sphinx v3 sounded better than the original model I heard 5-6 years ago so the technology is moving in a positive direction. I did feel the tube preamp added some texture to the sound and maybe that is the way to look at this....

Just heard the Rose Audio integrated- GaN class D 400 wpc.  Very nice.  

Thanks for the suggestions, indeed. It is a hard task to choose an amp without auditioning it. But since i decided to try another class D amp, it may take time and more efforts to come to decision. For example, I still have no clear idea yet on the sonic differences  between Purifi and GAN based amps, roughly (was not able to audition any of such amps).  I will check the other suggested options, but so far, I have no clarity. Would be helpful if you could be more specific on which features of the amp(s) you suggest you like or dislike. 

My first class D amp was PS Audio Stellar S300. I was really surprised how one can get that good sound for $1.5k.  I enjoyed it, it sound the best on live recordings, i like its compact size, the weight and it works completely cool even does not get warm. It is not an ideal class D amp for me, i think it lacks a bit mid-low frequencies. Exaggerating too mach, it sounds a bit like a megaphone, but it gives quite deep low and clear  high frequencies. My next class D selections were still not  ideal. The class D amp i am using now is Cherry Megaschino, the one I like the most among ones I had. It is not so traditional class D amp though because of its considerable weight, also it gets quite hot (hotter than my 200 watts integrated class AB McIntosh). But I think Megaschino is a better sounding amp, it somehow sounds more realistic and complete. Although the sound is somewhat clear and natural, compared to mu SET amp, exaggerating again, its reproduction is still a bit "dirty".  

As to the speakers, I use 3 pairs of Thiel speakers in different systems, CS6 in the main system with the 5.5. watts SET integrated, the bookshelf MCS1s with a Thiel subwoofer (that I currently use with the Megaschino) and CS3.6s. All of them are excellent speakers, I even never though to replace them.