Which Class D Amplifier? PS Audio, Ghent, Nord, Merrill or other???

I’m looking for a new amp & want Class D.

I’ve seen various brands mentioned, such as PS Audio, Ghent, Nord, Merrel to name a few, but I’ve not heard any of them.

Which company is producing the best sounding Class D?
Which models should I be looking to demo?


Which company is producing the best sounding Class D?

The only Class-D's so far that to use the more advanced GaN semiconductors for superior dead time and higher switching frequency that will give better sound. 
Are the Technics SE-R1 and the other is in your list, the Merrill Audio Element 118 monoblocks.
It won't be long for this technology to filter down to more affordable Class-D amps so be patient.

Cheers George  
Your answer begins and ends with Digital Amplifier Company. 

His design is fully proprietary, & refined forever. It's not Ncore, it's not Ice, or B&O or whatever.

He only sells direct, which is why you don't hear much about them apparently. I myself own the 'classic cherry.' Bought earlier in '18. Best amp I've ever owned and I've owned a bunch. 

Check out SPEC of Japan. I absolutely love my SPEC RSA-717EX. Beautiful tone. There are a handful of dealers in the US, I got mine from Pitch Perfect Audio.

SPEC makes a few different models but the house sound is the same. Jeff Day nails the sound in his review:

Jeff compares/contrasts the SPEC to a Leben CS600 and as an owner of the CS300 I can say his comparison is spot on.

The people who say "oh, class D, been there, done that" haven’t heard everything.
Thanks guys!

I should have said I’m in UK.   Looks like that Cherryamp are US only.

Certainly add SPEC to my list to check out.

From the ClassD I’ve heard, I’m already satisfied they’re at least as good as Class A - A/B costing double the price, but obviously interested in further improvement.
So I’ll be looking into this GaN situation.   

For the past two months I've been enjoying PS Audio's Stellar M700 monoblocks and these are the best sounding amps I've ever had in my system. My audio buds agree. With return and trade-in offers you can't go wrong by at least trying them out.
I am waiting for Ralph Karsten to finish his Class D amp. If anyone can build a great amp, it's him.

     The use of GaN semiconductors in class D amps, despite georgehifi's repeated claims to the contrary, currently have not been established as providing definitively superior sound quality to the technology and semiconductors employed in the better class D amps available on the market today (typically Field Effect Transistors referred to as FETs).

      As you learn more about how class D amplification actually works, you'll understand why reduced dead-time and higher switching frequencies have the theoretical potential to improve performance. 

      From my understanding, however, it seems that the GaN semiconductors reducing the dead-time has a greater potential of improving sound quality than higher switching frequencies do.  I believe this because faster semiconductors would reduce dead-time which would result in reduced distortion and likely better sound quality.

       The need for higher switching frequencies in class D amps is usually based on the theory that current frequencies are too low and cause sound anomalies in the human audible range of 20- 20,000 Hz.  Current class D switching frequencies are typically in the 400-600 KHz range with theory proponents claiming switching frequencies above about 1.5 MHz are required to ensure there are no sonic anomalies in the audible range.

     However, this theory has never been scientifically proven and there's virtually no evidence to support it.  Several class D amp designers. including the highly respected inventor of Hypex NCore Bruno Putzeys, have publicly stated there's no need for increasing the switching frequencies  above current levels. 

     For some unknown reason, georgehifi has continued to disregard the lack of evidence and has remained one of the very few people still stubbornly clinging to this unsupported theory.  Perhaps, in the spirit of keeping an open mind, it will be discovered that only a select few individuals are capable of hearing these supposed sonic anomalies but that's a bit of a stretch.

     I'm a big fan of class D amps and have replaced all of my previous class AB amps with them.  The class D amps in my combo music and HT system (ClassD Audio and Emerald Physics stereo amps and D-Sonic mono blocks) are smaller, lighter, run cooler, use much less electricity and sound much better than my old amps in all important criteria I care about.  Highly recommended.

     I definitely don't think there's a need to wait for GaN semiconductor technology to 'trickle down'.  As I believe you've already discovered, good class D performs exceptionally well.  If you're not afflicted with hearing sonic anomalies either, why wait?  Perfection can be the enemy of the extremely good.
      As far as good class D suggestions for you, I'm willing to offer a few brands/models to consider but would prefer knowing more about your system, needs and budget first.  

I listened extensively to the LKV Research Verito-1 and it is an excellent integrated amp based on the Hypex NCore. LKV also offers a stand alone power amp. Check them out!
The use of GaN semiconductors in class D amps, currently have not been established as providing definitively superior sound quality to the technology and semiconductors employed in the better class D amps available on the market today (typically Field Effect Transistors referred to as FETs).
The GaN btw is a developed by the same guys that gave us the Power-Fet all those years ago, they sold the rights to it to the world.

Once the GaN of their’s becomes affordable (with mass production), so that Putzy can get them, I guarantee you he will use use them.
If your spend your money now on the present technology you may have an unsellable amp when the GaN technology takes off.

I definitely don’t think there’s a need to wait for GaN semiconductor technology to ’trickle down’. As I believe you’ve already discovered, good class D performs exceptionally well.
But it still does not compete with the best linear amps.

Hypex NCore Bruno Putzeys, have publicly stated there’s no need for increasing the switching frequencies above current levels.
Of course he does because he can't go any higher "yet", and there’s never any mention from him or you (not that that matters) of the output filter (that is the real problem) that has to rid the switching frequency from the audio band and the effects it has on the sound, right down to 3-5khz.

I am waiting for Ralph Karsten to finish his Class D amp. If anyone can build a great amp, it’s him.
He makes great tube OTL’s for a small sector that use speakers they are suited to.
The Class-D is just going to be a money spinner for him, he buys the modules does a small mod so it can be said to be better, throws in in a box, and there’s his beer money.


     I stated the GaN technology will reduce dead-time and likely result in even better class D sound quality.  I believe this could be a significant step forward even though I have yet to hear an amp using them.  My main point being current good class D amps sound so great, why wait for perfection? 
     Class D amps utilizing current technology will not suddenly become worthless just because possibly even better class D amps are available.  How low current amps would drop in value relative to new GaN amps is likely to be a function of the actual sound quality and price variances between them.
     I do agree with you on the importance of the quality of the filters used in class D amps that removes the carrier switching frequency from the audio signal prior to amplification.  I believe improvements in these filters  probably has more potential to improve the quality of class D than raising the switching frequencies would have.  I was going to edit in some comments into my last post about the filters but realized my omission a bit too late.
       I don't perceive any sonic anomalies at all in any class D amp I own or have ever listened to.  Perhaps I'm just lucky or maybe it's just that no sonic anomalies in the audible range exist.
     I think not buying a current class D amp because the semiconductors are not yet perfected is akin to not buying a 427 Corvette in the 1960s because the fuel injection wasn't yet perfected.  In either case, you're just denying yourself the enjoyment of the extremely good due to a lack of perfection. 
    But experiencing the enjoyment of good class D is currently more important to me.  If I enjoy the sound of new class D amps utilizing GaN semiconductors or a higher switching frequencies more in the future, I'll probably buy a few if the price is reasonable.  I'll offer my current class D amps to both my sons at good prices.
     I'm also eager to see and hear Ralph's upcoming class D amp


@georgehifi ,
To say Ralph,
'  he buys the modules does a small mod so it can be said to be better, throws in in a box, and there’s his beer money',  
is a bit harsh and uncalled for.

To the contrary, his amps are quite stable for a wide range of speakers.
Those speakers with low impedance are difficult to drive even in SS.

Regarding Class D amps:
In fact, I have spoken to him about it and he seems to have come up with an ingenious way to deal with switching issues.
is a bit harsh and uncalled for.
Really Bob, I've acknowledged his prowess with OTL's, but let see if the Class-D modules are his ground up design or someone else's aftermarket ones, with "signature tweaks".
To the contrary, his amps are quite stable for a wide range of speakers.
And you are talking about the OTL's they are very speaker specific,
unless you throw a ban-daid "autoformer" fix on them, then that gives them a few more they can drive, but your better off getting an amp that can do the job properly in that case. 
Cheers George

  • Bel Canto Design Ref600M. They were amazing. I used them with Dynaudio Confidence C4 Platinum. Just amazing.
I'd have to say the Nuforce or Nuprime class D amps are definitely amongst the finest.  The ones Bob Smith at TDSS upgrades are THE finest and up there with the best sounding amps made.  I've tried my Nuforce Ref 9 V3 SE mono amps in at least 5 different systems with different speakers.  In all 5, the owners and all who heard said it was the finest the speakers and system had ever sounded.  Before the upgrades from TDSS, the amps were already very well reviewed and sounded very good.  After, they are more reliable and sound better in all the different parameters by a very discernible amount.  I've not heard all the different class D amps, but these amps I now own leave nothing to lust after.  They have power, great bass, detail and transparency, and are not hot on the high end.  They can drive pretty much any combination.  Mine will soon have the 500 watt power supplies installed.  They already had upgraded 350 watt supplies.   

Hello singintheblues, as others suggested, it would be useful if you can tell us your amp budget, the rest of your system, and what tone concept yours might be.... Class D amplifiers are as different as there are amps.

I am personally extremely fond of class D amplifiers designed/manufactured by Jeff Rowland.... They range from approximately $2500 for the M125 stereo/bridgeable model to some $58K for his top of the line M925 mono, which I own and dearly love. IMO the sweet spot of the Rowland line might be the M535 stereo/bridgeable at just under $6K.... A truly remarkable device... I am preparing a detailed write up on it to be posted to Audiogon. Yes, Rowland does have a UK distributor.... So, please tell us more about your requirements and preferences.

Regards, Guido


Not class D but I replaced a PS Audio Amp with a Benchmark Media Amp and the improvement was dramatic. I couldn't be happier with Benchmark.
I love my PS Audio's Stellar pre-amp and amp driving Tannoy's.  PS Audio is hard to beat for the sound/cost value.
The Red Dragon 500 are excellent amps.
     To date, I've used 3 different class D amps on my fairly inefficient and older Magnepan 2.7QR speakers (87db @1 watt):

ClassD Audio SDS-CS440 stereo amp. 44O W/CH at 4 ohms.

Emerald Physics EP-100.2SE stereo amp.  150 W/CH at 4 ohms.

D-Sonic M600 M3-600M mono block amps.  1,200 W/CH at 4 ohms.

     All drove my speakers well, have a decidedly neutral and accurate sound quality with noticebly better bass response and dynamics than my prior and decent quality class AB amps (McCormack and Aragon). 
     I'm currently using the D-Sonic on them because they sound the best to me due to the superior 3-D sound staging, life-like dynamic impact, tonal balance and the overall sense that you are at the venue or the musicians are in my room.  
      D-Sonic has replaced the M3-600M monos with their M3a-600M model which the owner, Dennis Deacon, stated now utilizes newer  Pascal class D modules instead of the original's Abletec/Anaview modules for what he described as a subtle improvement. 
     I've listened to the Bel Canto Design Ref600M amps in a friend's system and they are also very good with an overall sound quality that's very similar to the original D-Sonic.
     Please list your system, needs and budget for more specific suggestions.
Lyndorf.  You mean digital amp. Class D is one sort.  Lyngdorf is far better and uses Pulse Width Modulation. See their website: lyngdorfaudio.com. Peter previously owned TacT audio and has been manufacturing these types of amps for 20 years. And they mate perfectly with his Pre-room correction products and now integrated products too.  Best of all is that they can utilize digital and analog inputs, even HDMI. Better overall product than even Bel Canto at a portion of the price! As I said, all class D is is a digital amplifier. Pro audio uses those everywhere. There’s a world of difference here.
Nord Acoustics, when you call talk to Colin North he will fill you in on whatever you want info wise and set you up with a great deal, plus they Nord are in the UK. Products - Nord Acoustics  Nord One SE MKII
+1 Nuforce/Nuprime, particularly with Bob Smith's TDDS factory authorized mods. I had their monobloc Reference 9V3Se, then Reference 20 and Now Evolution One. Have heard many other class D and these are best I have heard. Disclosure, my Reference 20's are up for sale here, but with sale pending. They also use an original design versus standard or modified chips
NAD doesn’t get a lot of love on agon, but you might want to look at the NAD M22 v2.  Paired with the NAD M12 pre/DAC with BluOS module, they drive my Tannoy 8 dcti speakers quite well.
 I like Stevecham am enjoying my M700's .They can't be beat for the price. Collectively, a system costs are considerable so when you can get great performance and save a few to put into other areas in your rack you can get better balance. Steve, I would highly recommend getting a Furutech IEC and AMR fuses for the M700's. Those 2 tweeks made a considerable difference. The AMR fuses are awesome. I preferred them to all the others I've tried including all Synergistic fuses. Trust me.

+1 to Nord
I have the Nord One UP NC500DM stereo amp and it outperfoms in EVERY field my previously beloved 300B valve integrated (use as a power amp) Line Magnetic LM-508IA, wich is a very nice class A valve amp, very popular among audiophiles and cost almost 3 times the Nord. 
Besides that, if you are in UK, may be you can visit Colin to test his products.
Avoid Class D like monkey plague!
Good nod for Merrill, LKV Research, and we personally own Wyred 4 Sound SX1000 Monoblock amps. They have been great for me and our Magico A3's. They have been very reliable and affordable for the performance they give. The SX1000R's are even better. The LKV integrated also offers a lot for the $$ too.


"Avoid Class D like monkey plague!"

On what do you base your opinion??????
I reviewed the Benchmark Media DAC3 DX and AHB2 Amplifier for dagogo.com. The amp is superior to all the class D amps I have tried/reviewed in the past. Superb cleanness, resolution, highly commendable sound at a very reasonable price. It also has a gain feature that allows better matching with speakers than the class D amps I used. Note that it does not have RCA inputs, and uses either Neutrik and Benchmark cables, or Pos/Neg posts for alternative cables. I discuss this all in the review.
I've heard the Devialet at a show and they sounded good to me. I am sure there are other good class-D amps also.

I use the XTZ edge to drive my big Tannoys. Fine dynamic sound a little on the warm side. Low low cost. Good power. Gain control. Small size. No problems. Like an amp should be - let's you concentrate on source and speakers.
Bel Canto. Best kept secret is the REF500M, while not as powerful as the 1000M, they are slightly sweeter with astonishing midrange, clean (but not sharp) high end and slam and drive.
Like I said, I think you can´t go wrong with Nord.
Hulgich Audio, an australian speaker company, won the Best Sound Award in a HiFi Show on 2017 in Australia and second place in 2018, using Nord One Up Mono Amps and competing with system costing hundreds of thousands.
I think for the price is a no brainer.
Lot's of good options. Test them all and get back to us! ;)
Although I haven't personally heard any premium class D amplifiers, I believe that GaN will be a key technology and market driver.

For those of you unaware of GaN (or would rather just listen than geek out!), here's my analogy ... Non GaN transistors aren't as fast as GaN so it's kind of like listening to MP3's at a lower versus higher bit rate.

Personally I believe this is a great development for HEA.  Without getting into the differences between amplifier classes, GaN (at least on paper) should more accurately reproduce wave forms and require less filtering and other processing. With faster transistors we should get better sounding (hopefully great sounding) amps that are cheaper, lighter and more efficient.  Maybe then the ear bud generation will learn to appreciate great sound and expand the market.

To be clear I believe that linear amplification with the proper components will always be better.

Personally I'm anxious to watch the market over the next 18 months.  If the big guys (Yamaha, Marantz ...) start buying/using GaN in greater volumes prices will drop.  This would enable the brands frequently noted here to focus on improving the processing mechanisms for even better sound.

For what it's worth.
Bel Canto Design REF600M and the Black EX.
+1 on the Nord Acoustics, have the NC500 Monoblocks, I'm happy. You can also customize their sound slightly with interchangeable buffer boards and  op-amps. Mine have the Rev C. buffer boards, but I see there is a Rev D. buffer board recently released. It seems like an easy process to swop them out. I like that the amps are "user" upgradeable to a certain degree. Compact, light and runs warm to the touch even after some heavy listening.
Unless you've actually had Monkey Plague, you really can't say much about it.

Hi Everyone and Happy New years,


My audio distribution company has been A/B products for many years and a very good client of mine alerted me to very good sounding Class D last year because he said his big reference tube amplifiers had been outperformed by a set of used Class D amplifiers that he purchased as back up amplifiers. This client has great ears, a great system and lots of passion. I laughed because the last Class D amplification I heard, 5 years ago, was real average. But out of curiosity I contacted the Class D manufacture that my client liked and they agreed to sell me a set of amplifiers.


At the time my reference mono block amplifiers were $25K and I considered them very musical. After playing and direct A/B testing my reference Class A/B mono blocks over many years, I realized my reference amps did a lot of things really well but certainly, they were not perfect. I received the new Class D mono blocks about 2 weeks later and I had very low expectations after my first experience with the Class D amplification. All I can say is the new Class D amplifiers were not slightly better than my reference mono blocks, they were the next level and fully outperformed my reference amplifiers in every category. When this sort of thing happens, it really makes you question your audio intelligent. I was 100% sure my system was previously reproducing the original soundtracks correctly but with these new Class D amps there was another layer of music. Every song or track sounded new. The separation of the different singers and instruments were much more defined. Live instruments sounded more live and had more decay. Everything I heard at medium volumes could be heard at low volumes. There was more soul in my system but it was based on the amplifiers being more transparent and not injecting their own sound. This was very different than my previous experience with Class D amplification.


The main reason I have posted is because we now have 3 different Class D amplifiers that we are testing and another 3 different Class D amplifiers will be delivered to us in the next 3-6 weeks. I can already tell from the first 3 Class D amplifiers, that there are different levels of Class D. For the record when we test new products, we test on 5 very different systems. In this aspect you get 5 different honest opinions, 5 different listening rooms, 5 different types of systems, 5 different environments and lots of different types of music. It really can be fun.


At some point I would like to come back and give you our finding but best thing I can say right now is there are different levels of Class D, just like other types of amplifications and you need to decide what level Class D is best for you and your budget. I can say for sure that if you think Class D is not among the best sounding amplifiers in the world, than you have not done your homework or actually listened to current Class D.


PS; I have no invested interest in any Class D products as we do not carry any Class D products as of YET!


Bob at Worldwide Wholesales.

I don't know if the PS Audio Class D amps are the right solution for your system.  But I have their s300, at this point I am really happy.   PS Audio made me a great deal on my used amp and I had a trial period with the new S300.
Don't have any experience with Classe but There is  CA-D200 on ebay for $1.8K   claimed to be brand new in box.  Although located in Vestal, NY.  Classe still has the D200 listed as product on their website.  3 year old review. https://classeaudio.com/pdfs/Reviews/TAS%20CP-800%20CA-200%20Review%20Aug%202015.PDF
Unless you've actually had Monkey Plague, you really can't say much about it.

@wolf_garcia Whats YOUR contribution to this thread?

Current Class D has come a long way compared to a few years ago, who wouldn't want good amplification which is more efficient, takes up less space, runs cooler... and is possibly better value depending on which manufacturer you choose.

    wolf's thread contribution is requesting you should afflict yourself with Monkey Plaque prior to discussing so that your comments are well informed and relevant.

Please afflict yourself and report back to us.

Thank you in advance for your cooperation,
Class D has come a long way compared to a few years ago
No it hasn’t!

Mark Levinson had a good expensive dig and tried to cure it’s evils, with the $50kusd !!! No.53 monoblocks, which had massive series output filters to rid the switching frequency from it’s outputs, but they them selves bought a different set of problem to the table compared to all the filters others manufacturers use.
Again even with these, it’s the mid/tops that had ? on them, but as per usual with Class-D the bass was great.
" They resolved a remarkable amount of genuine detail but were harmonically threadbare, sounded somewhat hard and mechanical on top, and had a hazy overlay just below that. The bass was fast, lean, taut, and well damped—rhythm’n’pacing were among the No.53’s strongest suits. But overall, the nature of the sound induced listening fatigue. I rarely listened for more than an hour at a time, which for me is unusual."

The only "real" advancement of Class-D has been the introduction of the new GaN transistor which Technics introduced in to their SE-R1 and Merrill Audio is now doing with their Element 118, these promise to lower dead time and have a greater far reduction of the switching frequency with the filter without affecting the audio band.

Cheers George

I definitely don’t think there’s a need to wait for GaN semiconductor technology to ’trickle down’. As I believe you’ve already discovered, good class D performs exceptionally well.
But it still does not compete with the best linear amps.

I am also in this camp.  As a builder of audio components my partner and I have discussed making Class-D amps or anything similar.  So far, we cannot come up with anything that is better.  We recently built a pure class A power amp about 30wpc and it was killer.  Cost me about $600 to build one.

I recently heard the NuFocre (not the newest model) but an upgraded (with 5 watt power supply) and it was supposed to be really good.  But in direct comparison in my system it lasted less than a minute.  Just did nothing special and was not very musical.  Just my two cents.

If I was going to by a Class-D amp I would buy one that was reliable, could be serviced is needed and spend the least amount of money on it.  But that's just me, I'm cheap!

Happy Listening.  

eHello George, I have heard the ML NO.53 a couple of times, and... I agree 200% with the reviewer, for all parameters he mentioned.... To say that I did not like it would be an understatement.

If all other class D amps sounded like No.53, I would have never bothered adopting this class of operation in my system.... Thankfully, No.53 is an outlyer. THere are of course other class D amps that I have not cared for, but No.53 takes the cake, particularly at its nose-bleeding price point.

But George, haven't you learned yet that one cannot perform valid induction steps from a couple of anomalous samples?

As I said so many times.... Get out of the house, lots of nice stuff out there... Besides, who knows, you might even fall in love with No.53 *Grins!*



For a very honest product, within the UK, try Temple Audio from around Manchester. 
I did a similar research one year ago and considering my limited budget I ordered a pair of their monoblocks. I'm very satisfied and don't feel the hitch to change. Just took me a while finding a nice matching preamp...
And they make everything in house, from the amplification modules (proprietary, not ICE or Ncore or whatever) to the casing. They even let you personalise the cases - choosing the metal finishing and engravings. 
And one more thing, a very important one: the customer care is outstanding! Talk to John and he will answer all your questions. 
 I have heard the ML NO.53 a couple of times,
So have I, and the problems in the upper mids and tops while a bit different are there, they are also in similar way in all other class-D's I've heard.

I have not heard the Technics SE-R1 nor the Merrill Element 118, but the mids/highs areas of concern with Class-D that many hear, seem to be the areas they say they have addressed, which makes me very hopeful they are leading the way, to make Class-D hiend.  

FYI: I had 2 EP 100.2SEs (with upgraded fuses) for well over a year. I got the bug and bought a Audio Alchemy DPA-1 stereo amp. It is much richer in the midrange and bass, deeper and more holographic sound stage= much closer to real music

PS makes 2 amp versions 300 & 700.

The 300 likely uses a different module than the 700, which I am told sounds MUCH better

chances are you have the 300s