Class A or Class D solid-state amplifiers (modern designs)

@jonwatches1 

I have owned quite a few class Ds including; several W4S, PS Audio M 700s, Emerald Physics 100.2 SEs, EVS 1200 (based on dual mono IceEdge AS 1200 modules) plus loads of tweaks. I raved about for over a year, UNTIL, I got a LSA Voyager 350 GaN amp, which was about half the power, but easily twice the authority. It is so night and day from the EVS, that IMO, GaN (at least this one) should not be included in the class D designation

@bigkidz 

Thanks for the reply. I have one last question: have any of your creations been reviewed by a third party outsider with no horse in the race, like a magazine?  I am asking this because if you only listen to and compare your amps in your environment and with your specific associated equipment, that gives you a home court advantage. To my mother, I am the most handsome man on earth. While I accept your testimony, I would be interested in knowing what others think. 

Saying which is better, class A or D is like asking which is better, tubes or solid state. There is no definitive answer. Great and mediocre in all class types. Part personal, part associated equipment, part environment, part 'your' ears also come into play.

@spenav - much appreciated on the AGD experience - I will probably try and give the Tempo di Gani a listen

@twoleftears - appreciate the suggestion

Have a great day!

bigkidz clearly has not heard SOTA class D and so is unwilling to comment on Mola Mola or Spec.

I have a Rowland Continuum 500 Class D amp that runs circles around my two Plinius integrateds, one a model 9200 and the other a Hautonga. The Plinius Hautonga is good and I believe a dark horse at its price range, but the Rowland Class D is simply better driving Dynaudio C1 speakers. I recently had to send the Rowland for repair as both channels sounded wrong, one channel was slightly distorted while the other channel sounded muted. As it turned out both Icepower modules were malfunctioning and had to be replaced at a cost over $1,000. The Rowland amp was rarely used over its 10+ years of ownership as I was mostly overseas working so I only got to use it a few times every year whenever I was home. Yet both modules failed. The repair tech told me the inside of the amp was pristine and looked brand new, and everything else was on spec. This makes me think the Class D modules may not be built to the same very high standard as the rest of the amp. Not generalizing just narrating my experience. While I love the Rowland sonics next time I buy an amp it is probably not going to be Class D.

@atmasphere 

@spenav 

I have heard the amps you mentioned at length.  I knew Tommy O'Brien personally and he came to many of our Audio Raves back in the day.  He is a really nice gentleman and his products are excellent.  That being said, those designs cannot produce the sound of a Class A tube amp we manufacturer.  Again, everyone has what they want from their system.  We offer several options out of many available.  You don't need me to validate your system or any of your choices.  If someone is happy with their system and sound, that is what this is all about, right?

So what companies would I say are my competition - for the Class A tube mono-blocks I would say that's a good question.  I havenot heard that many that are point-to-point wired amplifiers using the best parts quality with customer made transformers and chokes, Audio Note non-magnetic resistors, V-Caps, copper plates, etc.  I have heard most of the typical tube amps most of you are familiar with but not many Class A tube amplifiers.  Lamm is a company that I would consider competition.  For the hybrid power amplifiers I would say Aesthetix Audio would be.

We have a fantastic music room in Northern New Jersey.  We are always open to host and have people bring equipment over to hear how things sound.  We are audio people and love to hear new things.

I am not trying to bash any manufacturer.  We need many manufacturers in the business to deliver products at various price points.  We modify and upgrade components weekly for people who what to improve the sound of their system.  We are happy to help.

Happy Listening.

@jonwatches1 

I have been using the AGD Audion mono for a few months and am still happy with it. Give them a try within your budget and you will be able assess for yourself. Most companies have a generous return policy. Good luck. 

This is supposed to be a little bit better than the monoblocks.

https://orchardaudio.com/stereo-ultra

If you're interested in investigating quality implementations of GaN at lower cost, this is where I would start (rather than the LSA Voyager or the Peachtree Gan 400).

@spenav 

Thanks! Those look like a lot of fun

I’m running a tube pre into a pretty conventional SS Class A/B amp, and think it would be fun to have a few amps around with different “characters”

Let me know if you give any of these GaN amps a listen - would be curious as to thoughts vs “conventional” Class D, to the extent discernible…

May add a Benchmark AHB2 in the meantime…always so tempting

@jonwatches1 

Check this one out, the reviews are very encouraging though I haven’t listened personally:

Hi - has anyone here with experience with Class D amps had a chance to listen to the new generation of GaN amps? Any worth a listen other than the pricier implementations? Thanks! Have a great day

@bigkidz

OK, so your amps at least to your ears are better. Fair enough. My question to you then is: what other amp(s) do you feel compare(s) favorably to your amps?

Objectivism ruled and high negative feedback gave vanishingly low THD and IM numbers.  However, the resulting sound quality got worse, not better.  TIM distortion was discovered, feedback was dialed back, and the importance of listening was once again proved.

This statement isn't entirely correct! TIM was simply caused by part of the amplifier being outside the feedback loop. With regards to 'high feedback' there were none in the 1970s that had enough Gain Bandwidth Product to support that feedback at high frequencies- so at higher frequencies the feedback fell off and distortion increased- resulting in the 'harsh and bright' solid state sound that has plagued solid state amps since their inception.

his statement was to me that he has heard amps that compete - so since I cannot get a hold of his amps - I am asking him to provide me with his experience based upon his response to me.

To date, we have not heard a class D amplifier that competes in sound quality.  We are open to hear something that comes close but not yet to our ears.

"I have. FWIW class D amps vary at least as much in sound as tube amps do."

The amp that convinced me that we needed to being working with class D was a Cherry amp. I've not heard the Orchard but it seems to get very nice comments. A couple of customers have the AGD amplifier and are very happy with them.

The bottom line is you can't say if you've heard one you've heard them all! I've heard some that I had to really ask if the manufacturer was serious (that was a long time ago).

Sounds like I should dump the Boulder 3050s and go for a pair of Hypex monoblocks. 

@bigkidz, so what is your opinion of Mola Mola and Spec for example, if you are still waiting to hear the great Class D sound?

I'm reading and learning a lot from you all. Thank you so much! I'm humbled.😊

Lyngdorf anyone?      : )

@tunefuldude it is easy to make a cogent argument for them, providing that one abides the loss of “purity”… which is sort of tied to the remove of simple tone controls.

Certainly easier to get a good sound without going to heroic measures. (IMO)

Glad you're enjoying the sound of the amps that you manufacture and sell.

Until a few more of them are out in the wild in the hands of consumers, of course we won't be able to get even the beginning of something approaching an objective assessment.  And even then...

@spanev - his statement was to me that he has heard amps that compete - so since I cannot get a hold of his amps - I am asking him to provide me with his experience based upon his response to me.

To date, we have not heard a class D amplifier that competes in sound quality.  We are open to hear something that comes close but not yet to our ears.

I have. FWIW class D amps vary at least as much in sound as tube amps do.

Your posts offers some examples:

Specifically, we are referring to amps like the Merrill Audio Element 116

Merrill Audio - Element 116 Power Amplifier Monoblocks

the AGD Audio Gran Vivace

AGD Gran Vivace Monoblock · AGD Productions

the Nuprime Evolution One

The NuPrime Evo One Mono Amplifiers - Review & First Listening Session - SONIC UNITY

the Technics SE-R1

Technics SE-R1 Stereo Power Amplifier – AudioCubes.com

the Theta Digital Prometheus

Prometheus | Theta Digital

to name a few.

Take a listen when you get a chance an let us know what you think.

Heard them all but the Theta Digital Prometheus.  IMO they do not compare wo what we manufacturer.  Our opinion may be different that other peoples but I am open to anyone bringing something to our listening room as we are always open to hear something.  We are also looking for the best we can hear for our systems.

Happy Listening. 

Lyngdorf anyone?      : )

I’m surprised no one mentions SPEC CORP, outstanding amplifiers. Another may well be LFD I suspect, who have recently turned their hand to class D.

I have been listening to the Coda #16 with it’s first 100 watts of class A for almost a year now and recently brought in AGD Audion mono blocks. The Coda, to me is the pinnacle of class A goodness. I love the dynamic power. The AGD mono’s are right there with amazing speed and dynamic force of their own. I continue to switch between the two and right now I am leaning toward the AGD as my keepers. Not to mention the AGD is almost half the price of the Coda. So the Coda might be for sale soon.

Thank You to all for the insight. Goes to show that my friend was right. This is easily the best audiophile forum on the web.

Class D Orchard Audio Ultra Amplifier. No other will do for me. 

I have some really nice Class A amps. Though my fav amp is still the cheaper non-Class A Benchmark AHB2. I just wish it had more power, though in Mono configuration it is high powered for speakers above 2 Ohms. It has that clean Class A sound and is very smooth. I feel it is just the most crystal clean sound I have heard from any amp.

The stock LSA Voyager GAN 350, mentioned a few times above, is good but after the very low-cost mods by EVS it sounded a lot like the AHB2, my highest compliant for an amp. I sold the Voyager since I liked the AHB2 a little more. I kind of wish I kept it as a backup.

As posted above the AHB2 is not Class D.

@bigkidz

My previous post answers your question. Why do you want Ralph to advertise for other people? Would you go to GM and ask them who else makes good trucks?

FYI…Benchmark is not a class D amp. It’s a whole different animal. 

I would suspect that a good salesman would not claim that others are close or better.

But I have also heard nothing but good about Ralph’s work.

There is Purifi and Benchmark that are generally well regarded amps in the Class-D space.

Or… personally… I would only be looking at those three for class-D HiFi amps.

@atmasphere besides your class D amps what others do you feel compete?

Thanks

@atmasphere  Are you showing these at Axpona?

Actually, the 70s were the Spec Wars.  Objectivism ruled and high negative feedback gave vanishingly low THD and IM numbers.  However, the resulting sound quality got worse, not better.  TIM distortion was discovered, feedback was dialed back, and the importance of listening was once again proved.

Anyone remember the Leach amp, designed by Marshall Leach?  Another young amp designer to emerge at this time was Nelson Pass.  His Threshold CAS amps were the result of a design exercise in minimizing the need for feedback by optimizing the circuit's inherent linearity.  While he was already producing STASIS amps, the CAS line brought his work into a more affordable range.  In many respects, they're the progenitors of First Watt.

In other words, could you have equal technical performance and quality in a Class D amp?

@jackhifiguy by what measure would we consider equal “technical performance” and “quality”?

To date, we have not heard a class D amplifier that competes in sound quality.  We are open to hear something that comes close but not yet to our ears.

I have. FWIW class D amps vary at least as much in sound as tube amps do.

See if you can find an Audio Research DS225 or DS450.  Class D, but their own design - not just ICE modules in a different box.

Bel Canto e One REF501S is very nice class d and very affordable.

another +1 for the LSA Voyager GaN 350

My friend asked for a recommendation to replace his Cambridge amplifier, traded it in for the LSA Voyager and thank goodness it was so much better.

I'll most likely go to GaN myself, just going to let designers play with it some more. I read with interest on the Atmosphere monos but my speakers are a little thirsty, and I'm running 2 x 400watt (not that I run them at 100%) at the mo.

My previous amps were all class A mono blocks from Krell and BAT, then I switched to PS Audio M1200 and couldn’t be happier. They sounded great and are cheaper than my previous amps. 

Ck out the Jeff Rowland Design Model 125.

+1 for the LSA Voyager GaN 350.

It is very chameleon like. Lovely oldies like Ella and Louie, Leonard Cohen sound full bodied rich and in the room. Lessor recordings sound, well, Lessor. Great value MSRP $3000, a veritable bargain compared to many class A or A/B amps whose MSRP are multiples

Sound improved considerably by replacing stock footers with Nobsound springs @ ~ $35/4. Now under all my kit, including speakers

Hi, about 10 years ago I owned a class D integrated from nuforce. on the long run I was not happy with it (too dry, a lack of soul) and I sayed to myself: never again class D! but that is foolish. things have changed very much. a few years now a class A preamp is working together with a class d power-amp from a little company in poland named acuhorn. it is a joyfull combo and I am pretty shure it is hard to beat in this price-category. I was very skeptical, but because of the money-back-guarantee I ordered one acuhorn rate-amplifier and he is still making music in my living room every single day.

Has anybody had the chance to listen to LSA Voyager and Starkrimson and Hypex NC400?

TCO is total cost of ownership--I'm guessing he means power bill.

TCO for class A should include the cost of back surgery.

Check out the new Topping PA5 Class D amp. $349! Clips at 110wpc@8ohms with 1% distortion. Uses advanced circuitry and has an input level control. Ranks just below the Benchmark AHB2 in SINAD at 1/10 the price! 

Perhaps forget about 'technical performance' and configuration.  By 'quality' I presume OP means sound quality.

That's what all of us are looking for, but it cannot be an absolute - each of us has different tastes in sound reproduction.

So I suggest OP  just goes and listens to a range of amps of many configurations and takes the ones he likes best.

You aren’t going to find better measured performance than a pair of Hypex NC400 Monoblocks.

Re comment above by atmasphere I can understand one of the reasons why my class A/B monoblocs sound so good - they use zero feedback and run very high into class A (400w each at idle). BAT VK655SE's.

This is the only current amplifier that I have heard that left that feeling of that is special with me. Not sure what class it is but I know to me it was special! With the continuous increase in use of the internet there are very few brick and mortar stores left around here where top end equipment can be heard but this set of amplifier s I heard and really loved. 

If I were looking for a new amp, I would be looking at Mola Mola monoblocks.

@goheelz 

Specifically, we are referring to amps like the Merrill Audio Element 116

Merrill Audio - Element 116 Power Amplifier Monoblocks

the AGD Audio Gran Vivace

AGD Gran Vivace Monoblock · AGD Productions

the Nuprime Evolution One

The NuPrime Evo One Mono Amplifiers - Review & First Listening Session - SONIC UNITY

the Technics SE-R1

Technics SE-R1 Stereo Power Amplifier – AudioCubes.com

the Theta Digital Prometheus

Prometheus | Theta Digital

to name a few.

Take a listen when you get a chance an let us know what you think.