Competitive class D amp suggestions

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. 

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....

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

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

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 - 

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!

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.

@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.

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 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 🎶 

@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/

@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. 

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

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.

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.

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

How is the PS Audio Gear? 

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?

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. 

Interesting. 

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.......

@ 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

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

http://www.bantamone.com/

I had the PS Audio M700s when MSRP was a realistic $2k. I liked them but they didn't couple well in my large room. Their M1200s were on my radar, but took too long to bring to market (just as well with their absurd $12K MSRP) I replaced them with EVS 1200 (exact same modules as the PS Audio, but highly modified by Ric Schultz @ 1/4 the MSRP), and though I raved about it and the benefits of 2-3 times the wpc, when I got my Voyager GaN 350 (~ half the EVSs power) it locked into my room in a way that the only other other amp I owned ever did; the Kinergetics KBA 75, pure class A power meter spinner

+1 on the Primare. I also have the I32. The I35 should be noticeably better, I expect. 

@agdproduction , thank you for your input. 

@ricevs, your comments were very useful, at least i clarified some things for myself. Design issues also have some (superficial) importance. These "tubes" and the AGD amps look look attractive to me. I would now wish to know how they sound, especially, given that they are about twice more expensive then most of the comparable amps.  (..."making money is good..."  (:  😉) 

@kuribo , thanks for your input on Peachtree Gan 400. It is important to have different opinions here and your arguments seem reasonable.  

ps audio having a great sale on their m1200 monos now for month of may

How is the PS Audio Gear? 

I also had a Stellar S300 for around a year.  Drove my Maggies flawlessly, always ran cool, and it was a steal at that price.  I replaced it with a Bryston 4B SST2 that fell into my lap at a price I couldn't resist.  I am sorry that I sold the S300, but used the proceeds for another upgrade.

@orchardaudio and @atmasphere thank you for your comments and the link. I read them with an interest, they sound convincing. 

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.

This is a very strong and challenging statement, especially from a tube amplified producer (i appreciate it very much). I did believe in this a few years ago. Nevertheless, so far, as mentioned earlier in this thread, i did not find a class D amp that sounds as good as  my 5 watts tube SET class A amp. Perhaps, Orchard and Atmosphere  already produce such class D amplifiers... 

@orchardaudio and @atmasphere, do you expect to have a further breakthrough is the design of your class D amps in near future? 

I realized that i don't have an answer on the following (perhaps stupid, forgive me) question. Would it make a sense to combine somehow GaN transistors  with Purifi modules in a single amplifier? 

Primare makes some great Class D amplifiers, they do not have the coldness some class D amplifiers might have. Indeed they sound liquid, have the clarity and the black bacground. Aavaik makes some great class D amplifiers as well but at a much higher price point. 

However, nothing can replace a Pass Labs class A amplifier weighting 100lbs having 2KVA power supply, be sure about that.

@evank "I have the Rogue Sphinx 3 and with the stock tubes it was very thin sounding. I put in a pair of Mullards and it beefed everything up"

I have not heard the Rogue Sphinx V3, so I can’t say that it is or is not thin sounding with stock tubes. Herb did not mention anything about it sounding thin in his review. Perhaps it depends on what you are pairing it with, source and speakers? It is good to know that you found that it actually responds to tube rolling. That could be some fun. I like the no nonsense look of it, especially in the black. The black makes those knobs pop, plus the graphics are more legible. Herb liked it paired with the Lintons, kef ls50, and the Goldenear BRX. I don’t like that it has increased in price by 200 bucks, but like everything else, it is the norm nowadays.

Class D competing with class A? No way..two completely different animals. 

The M1200s are now $4398. Stock Ice Edge boards but their own tube input. Ric Schultz introduced  his EVS1200 a good year before them using the same Ice Edge modules, but in one chassis, plus all his technical and mechanical skills. No longer made, it was ~ $2500. I have one, that I would consider selling it at that price

I've known Ralph for a while and have been an Atma-Sphere customer for some time owning an MP-3 preamp and M-60 OTLs. I have had the Class D amps in my system now for about 6 weeks. In the simplest of terms I will say they made the OTLs obsolete. On top of that I have lent them to 2 people and both of them placed an order after their listening comparisons.

I have Bel Canto REF1000 MkIIs and while I think they are a very good Class D amp, I prefer the Atma-Sphere. In my opinion they have all the attributes of a tube amp with the transparency and speed of an OTL, as well as no heat to deal with and they are much more power consumption friendly. In comparison to the LSA, the LSA came off grainy in the upper frequencies, it was clearly heard after listening to the Atma-Sphere amps.

@clio09 , thank you for this post. 

In comparison to the LSA, the LSA came off grainy in the upper frequencies, it was clearly heard after listening to the Atma-Sphere amps.

 What you precisely mean with "grainy in upper frequencies", can you be a bit more specific on sonic differences between Atmasphere class d and LSA Voyager amps in different frequency ranges?

@niodari first I will say at it's price point, especially if it was purchased with the introductory discount, the LSA amp is a good value. There is a lot to like about it. However, the upper frequencies did exhibit some distortion, it's overall balance is inconsistent as a result. For example, trumpet would start to sound a bit harsh and grainy, almost aggressive and lacking smoothness in comparison to the Atma-Sphere amps. You can hear this on drum cymbals as well, especially in more complex passages. The violin loses some of it's natural tone. The Atma-Sphere, like a well designed OTL, which Ralph manufactures as well, doesn't exhibit this level of distortion. It is a very smooth and balanced presentation. If you go back and re-read his post above he provides the answer to this very clearly.

@clio09 , clean highs is very important. At the same time, this sale came out now and somehow is motivating me to take this choice. At least, i will know what can be wrong and will see how critical this issue is, thanks again. At this moment, perhaps, i am not still convinced/ready to pay twice more for something that i have never heard. In any case, i have the 5.5 watts SET amp here in my main system. 

@clio09 can you help with another feedback before I take the final decision

do you think that Orchard GaN monoblocks (150 or otherwise 500 watts) can be any better than Voyager ( in particular in terms of the distortion in high frequencies)?  Which of these amps you would choose?

ATI?

@niodari, other than the Class D amps I previously mentioned, as well as the Merrill amps, I have no other listening experiences I can share. I will say this, it is worth paying attention to some of the unique design aspects of the Atma-Sphere amps when compared to other GaN amps. As Ralph spoke to in his post they eliminate what is wrong with solid state amps in general (and too an extent tube amps as well), not just GaN amps. As a tube amp designer it was a revelation to him, and he has been doing this for nearly half a century.

The supposed harshness in the Voyagers high frequencies: As a long time audiophile, I can tell you that vibration and isolation make a huge difference in sound quality. All my kit is currently resting on Nobsound Springs (see Amazon), which are very cost effective, and downright cheap considering what they do. FYI: there is a forum page about how to use them.

As mentioned, I have a LSA Voyager and did not like the sound using the supplied feet. Ditto the supplied power cord.

Other things that matter: my Emerald Physics 3.4s (no longer in production) have 12" woofers with 1" concentric polyster tweeters. If one's speakers have metal tweeters and low quality ICs/PCs the sound of any component will be compromised. Also, the source and its cabling, lack of good isolation/vibration will negatively affect the sound

hth

I have a pair of Bel Canto REF500M amps that I bought here, and love them. Lots of detail and plenty of power to drive my KEF LS50 Meta speakers, which are not very sensitive. I upgraded from some Rotel RB-850 class AB amps, so my setup was never expensive, more mid-fi, but I think the Bel Cantos are the biggest upgrade to sound that I’ve had in my modest system. Bel Canto also has more expensive gear in their Black EX and Black ranges that could be worth auditioning in person if possible.

Don't overlook this, too; there have been very good reports on its sonics.

https://www.dedicatedaudio.com/products/bel-canto-design-ref501s-stereo-amplifier

@tweak1 , thanks for the suggestion. Is the vibration you mentioned caused by CD players and speakers (I understand that amplifiers cause no vibration)?

Some amplifier power supplies/transformers can create high frequency vibrations when they are not properly isolated (Ric Schultz/EVS addresses that with his mods), as well as external vibration from the speakers feeding back into the kit

Other very suspect components that can contribute to high frequency glare etc, are the transport, the dac, and the digital cable

hth

D-Sonic amps. I owned the "800s M3a" for a few months and was recently thinking of getting one back since I was considering a low cost and decent sounding amp. They use Pascal modules. I did not get it since I did some other changes the negated the need for an extra amp.

I did not perceive any harshness in my Voyager. It was just a very clean sound, especially so after the EVS mods. It certainly was not warm, like a new KRELL XD or a CODA #8. The Voyager was closer sonically to the Benchmark AHB2.

This is a very strong and challenging statement, especially from a tube amplified producer (i appreciate it very much). I did believe in this a few years ago. Nevertheless, so far, as mentioned earlier in this thread, i did not find a class D amp that sounds as good as  my 5 watts tube SET class A amp. Perhaps, Orchard and Atmosphere  already produce such class D amplifiers... 

@orchardaudio and @atmasphere, do you expect to have a further breakthrough is the design of your class D amps in near future? 

I realized that i don't have an answer on the following (perhaps stupid, forgive me) question. Would it make a sense to combine somehow GaN transistors  with Purifi modules in a single amplifier? 

To the last question, no. The reason why gets really technical fast!

To the former question, I suspect any manufacturer in high end audio is looking for ways to improve their product, but I don't expect a 'breakthrough'; IMO/IME the breakthrough has already occurred- you can now finally buy a solid state amp that sounds better than the best tubes can offer (with the same liquidity, no harshness but with greater detail including depth), with the possible exception of the sound at overload (but for that just make sure you have enough power).

Hi Ralph: Do you any plans for a Class D preamp in the future?