I have recently paired an Audio Research DS225 Class D amplifier with an Audio Research tube preamplifier (SP8 mkii). I cannot believe how wonderful and lifelike my music sounds. The DS225 replaced an Audio Research SD135 Class AB amplifier. Perhaps the SD135 is just not as good as some of the better quality amps that are out there, but it got me thinking that amazingly wonderful sonance can be achieved with a tubed pre and Class D amp. I have a hunch that as more people experience this combination, it will likely catch on and become the future path of many, if not most audiophile systems. It is interesting that Audio Research has been at the forefront of this development.
Sorry, but we wouldn't even be having this discussion if great class D amps had been around for ages.
Judging by the measurements I keep seeing, great class D amps still haven't arrived.
That's the first mistake.
Look, I use technology a lot. A LOT!
I believe in it, but I also know the limitations. It is one thing to measure distortion given our most common measures: TIM and THD+N They may tell us very little about how this is perceived or how it affects music reproduction to the human ear/brain/pleasure centers. I can critique practically ANY amplifier to death.
And also, take a look at some of the most highly touted amps out there. They aren't exactly stellar spec performers.
My point: Human beings perceive sound differently than pure specmanship. If you want to go "by spec alone" then you really can't make any claims at all. I'd argue that based on the literature, some Class D are excellent amps and no one can hear better. My point? Your own ears are FAR better judges of quality and pleasure. Find me a measure that compares pleasure to transistor speed and I'll be really interested, but claiming that there's X parameter that Class D amps have to overcome before you admit they are excellent is hard for me to accept.
Do you know what I cannot argue against? People saying "I heard Class D amps by X manufacturer, and I did not like them because they sounded like ..."
That's fine.
But me? I've heard great Class A amps from highly touted makers and I preferred Class D.
And here we are back to my overall thesis:
Buy what you like listening to, specs and other people's opinions be damned. It's your wallet, and your time on earth that is important. No specs, no transistor speed, no class (A/B/D) matters when it comes time to spend your money. Make yourself happy. What I lack, is a belief that a specific set of technical specs can be made so much better in Class D that they would change everything. Sorry, I like what I have. Show me not the spec but the performance and I may want more.
George makes up something untrue about Merrill amps and all he can do is say that whatever I say is biased because I am selling something. The truth comes from different places.....even from manufacturers. My amps will speak for themselves. If they are good, they will sell. Trust no one (neither George, nor me nor anyone). Trust your ears. Listen and decide. You cannot know anything about how something sounds without listening to it. Class D (and all classes) are getting better and better. Whatever you heard before is not what is best today.
All class D amps have the switching noise superimposed on the audio signal. However, how much does a low level 500K sign wave affect the sound you hear? Pretty dang far out of the audio band. It does make sense to use a higher frequency so you can filter higher and have even less noise......but how much does it do audibly? Only those that have tried it know. All else is a guess. Personally, I believe it would make more difference to use better coils and caps on the output of the amps. Cryoed PCOCC inductors and super capacitors would give way better sound. No one is doing this. The future is bright indeed.
Now, single speed DSD has a problem with noise, for sure. The noise at 50K is a lot and that can fold down into the audio band. I read somewhere that double speed DSD has 40db less noise at 50K (40db is 100X!!!). No wonder it sounds better. Quad speed is a little better yet.
It will be at least 5 years before there is an absolute state of the art class D amp. There might? be something like that available now in class A in the AudioNet latest amps ($105K the pair)......or maybe the D'Agostino monsters ($250K the pair.....and 574lbs each).
Yep George, 'tis all one dark ominous conspiracy at the expense of brave audiophiles worldwide... There are rumors of a mysterious kabala of notorious class D mongers to undermine the Faith of righteous audiophrenes. Could even be the "deep HiFi State at its most nepherious purposes"... 'Best continue to read 'em safe reviews and specs instead of getting out of the house and exposing your ears to the spiritual corruption of unsafe audiophilic experiences *Grins!*
Show me where it is stated that the Merrill uses higher than 500K for its switching frequency. In fact, Merrill stated (on this site) that higher frequencies for switching were harder to do. I hope Mr. Merrill steps in here and clears this up. What he seems to claim is that the zero dead time using GaNs plus his zero feedback circuit are what makes the great sound.
Nuprime is using 700K in their latest amps and they are said to be making some very nice sounds.....also has 1meg input impedance and very trick power supplies with discrete front end. Their amps are using Mosfets on the output.
The new IceEdge modules have "dead time compensation".....maybe that is why they sound so good.
There’s always a next-great thing. In the case of fast transistors, cool. Show me an audible benefit that everyone can hear before I get that hyped up about it.
It’s what the present Class-D "cons" are all about, listen to a SE-R1.
I’d lay money on it, that you’ll put one of the first with your hand up for one when it suits your pocket. And your old one with the lower switching frequency, will become unsellable junk save for use as a bass amp.
I'm happy for manufacturers to be pushing the envelope. That's great. All I'm saying is that the idea that the next great thing is just around the corner and it's the end of all audio is a little over hyped.
There's always a next-great thing. In the case of fast transistors, cool. Show me an audible benefit that everyone can hear before I get that hyped up about it.
George, Merrill is not so much interested in achieving high switching frequencies. He seems to be using GaN to reduce dead states.
BTW, here is the latest Merrill newsletter, where he talks about the Element 116, which he will sell for about $22K. a further trickle-down Element 114 will eventually retail for about $12K.
While there are lots of fun puzzles left in the world of audio technology, solving them may or may not have appreciable benefit to end listeners.
That’s something only listening for yourself can decide.
Selling you a problem you didn’t have in the first place is what drives the industry.
The trouble with the Techniques amps is that you can't attribute their sound just to 1 technology. This is a pretty remarkable amp, but there's also DSP speaker impedance correction going on. You cannot say "great amp, must be the super fast switching speeds" unless you can eliminate other variables.
Are fast transistors cool? Of course they are. But great Class D amps have been around for ages.
Yet here is George, standing outside an airport with a sign saying "Planes can't fly!"
Just found it, as yes they do state because of the GaN transistors ""which allows fast switching" but it puzzle me that they don't state how fast they switch at like Technics does at 1.5mhz. And just like the Technics not cheap either at $36k
For more information, you may want to contact the company.
Regards, G.
If they are using these EPC GaN transistors in this prototype, the only reason would be to be able to attain a far higher switching frequency speeds to 1.5mhz like Technics with the SE-R1. Can you point to a link where you saw this is stated??
Hello George, as far as I know there were no "evaluation boards" of any kind in the Merrill Element 118 prototype. The circuit is entirely designed/implemented by Merrill from the ground up using discrete components, including the in-circuit application of GaN transistors.
For more information, you may want to contact the company.
kosst_amojan said... "people replacing SMPS's every day and every guy who's ever worked on CNC machines. There's nothing cheaply or poorly engineered about Mazak or Haas machine tools and they can't seem to make these power supplies last."
Heat buildup inside any CNC machine beyond the intended tolerances of said machine will most definitely put a strain on all internal parts. Not to mention the vibration from motors and the humid conditions in and around the machines from in shop humidity levels and the coolants used to reduce friction. There are many variables in an industrial setting to make any well designed piece of equipment go south in a hurry...
^Yes, George. and that was th case with all previous class Ds that I owned, but, the Audio alchemy is different. I can hear the resonance and warmth of same inside acoustic guitars, coronets...
FYI: as much as I hated to, I sold my Hattor XLR, but the Audio Alchemy DAC/Pre is damned nice and pairs perfectly with my AA stereo amp
One point to consider with most digital is when they fail many are not repairable.They can dump a load of current and burn your speakers depending on the protection circuitry. Any professional repair center can keep your old systems running for life. Retro rule in my opinion, going back to the nad 3020.That ones tone is mind blowing. Haven't found a digital which can compete.Most digital are to clean for my ear.
I have an NAD C 268 class D amplifier, NO PREAMP, and mac mini DAC using 3.5 mm line out and the sound is MAGICAL and I've heard just about everything. I think the main is reason is that there is no preamp, but for whatever reason, the sound is just incredible.
I have had a mono amp in my system designed around Gallium Nitride (GaN)
Which EPC "evaluation" board was this last spring? as this is the only way to get them as far as I know?
As far as I know this board is the only one EPC (using GaN transistors) that’s been released so far, The EPC0106 at $1338.00 usd, no transistors only yet.
Hello Tweak1, are you referring to amps designed around Gallium Nitride transistors? I have had a mono amp in my system designed around Gallium Nitride (GaN) transistors for just a few days last spring. It was a still incomplete but lovely prototype of the now released Merrill Element 118 monos. At the time, it was not fully broken in and still showed some minor artifacts. In spite of that, it showed high promise, Yet I could not get a complete idea of its performance within the limited hours of up-time.
You seem like the perfect candidate to get the GaN amps
I have owned 4 different gen class Ds, Parasound A21, and a behemoth Kinergetics KBA 75, which I think was puree class A. It grabbed a hold of the heads on my then Genesis Vs, like none of the other amps I tried on it
Actually I have owned Class D and class A/B amps....
Aragon 4008 Mk.2 stereo A/B -- Nice but limited performer.
Rowland 7M balanced high bias mono class A/B -- Wonderful golden tone... Absolutely captivating, with huge sound stage and power reserve... but does not compete with current designs in resolution and distortion.
Rowland M312 stereo class D -- Fabulous 2nd generation class D based on ICEpower 1000, with PFC rectifier prefixing the regulated SMPS, and Lundahl input transformers... Would stand up even today, IMO.
Early production Rowland M625 stereo class A/B... Very sweet and transparent... But could run out of gas on extreme transients.
Rowland M725 mono. Original non-S2. Overcomes all limitations of original M625, and edges above M312.
Rowland M925 mono class D -- An incredible performer in a class of its own that I have owned since 2013... I adore it... I have not heard an amp yet that exceeds it in its totality. A total keeper.
Rowland M535 bridgeable class D -- I am evaluating a bridged pair... Jaw-dropping music maker, particularly considering that each chassis in stereo mode lists a smidgeon below $6K.... IMO worth a few times its list price. If M925 did not exist, a pair of M535 would be my long term choice.
Funny, I haven't read anyone comment about having owned both class d and
a-a/b. I'm very interested in what they think. This thread, as well as
the entire audiogon forum, is populated with either/or, one or the
other, with very strong advocates in both camps.
I haven't been paying close attention to this thread, so perhaps someone has already responded in a similar way.
I've owned many amps that use differing underlying technology. I'm including integrated amps in the lists below.
For class A/B I've owned the following brands - Rotel, Parasound, Krell, Lexicon, Marantz, and Emotiva.
For class D I've owned the following brands - Wyred 4 Sound, Peachtree, and Sunfire.
For tubed amps I've owned Rogue Audio and Audio Research.
I recently purchased a Heed Elixir integrated that uses what Heed calls "Transcap" technology.
I have not owned any pure Class A amps.
I think they all have strengths and weaknesses and what really matters at the end of the day is how they sound. A lot is going to depend on the way the designer understands and implementsed the technology and the level of the build quality and components.
Out of all the amps I've listed, the ones that I have liked best (and still have) are the Rogue Audio M-180 tube monoblocks, the Wyred 4 Sound Class D ST-1000 MKII, the Audio Research tube VSi-55 integrated, and the Heed Elixir integrated.
It's hard to imagine the entire market going in one direction or another. Designers may be more knowledgeable about a specific type of technology or prefer the way it sounds and so it seems logical there will continue to be diversity among design and implementation philosophies.
Funny, I haven't read anyone comment about having owned both class d and a-a/b. I'm very interested in what they think. This thread, as well as the entire audiogon forum, is populated with either/or, one or the other, with very strong advocates in both camps.
@kosst_amojan The Berning TF-10 is a tube preamp with about 10 tubes in it. It draws about 60 watts; that's about the same as my laptop charger.
Panasonic came out with a new formula for electrolytic capacitors some years back that allowed them to be a lot smaller with good performance. Chinese copies of that part proved to be unreliable but due to their price found their way into a lot of consumer gear- laptops, chargers, that sort of thing. So I've become hesitant to blame electrolytics for failures generally speaking, until I know more about the actual part used. If its one of those knock-offs, its going to fail no matter what.
You can mess up any amplifier operating class. The specific implementation is more important. Class A implies better quality than D or inverse F, but that "class" system is not a value scale. Class A sets the zero signal in the middle of the operating range, as to avoid the typical non-linearities at the extremes of the device's transfer curve. This was in started in the tube age. Many later semiconductor devices had poor linearity, which was "fixed" with gobs of feedback, and transistor power amplifier output stages almost exclusively have no gain, they just operate as voltage followers/current amplifiers. So linearity biasing is not the goal here, but avoiding ugly transitions when the voltage crosses the zero point. There would be more work getting a D amp to perform well, but of course as this thread has shown it is possible. The digitizer must be very good, operating at a high frequency and have good filters for the output. Higher frequencies will be easier to filter out and will have more resolution. The bit stream output from a DAC could be used to drive an output stage, perhaps skipping some time middle pieces. Change the power supply voltage and the gain changes. Obviously junk in the power supply will end up in your ears.
Laptop chargers, battery chargers, TV's, you name it.
-Which don't draw any more power than the Berning TF-10, FWIW. I had a USB power supply fail on me when I took it on the Grand Divide Mountain Bike Route, but that was likely due to vibration more than anything else- the Tour Divide (as its known) has a way of doing that.
New to this site. My first new amp in decades, bought Rogue Sphinx V1 integrated three years ago. Tube 12au7’s in pre with class D power. I bought unheard but was not disappointed. Rolled NOS Mullards into it. I think it is a good value. Doubles 100 to 200 wpc at 4 ohms. Nice phono for MM carts. Heavy transformer. Quality build. Have added a Schiit Loki four band equalizer to play with. Also reccently added Rogue Cronus Magnum, but that’s not a new design.
I too hav3 class D A great small company in Denmark Pascal Audiomake excellen5 digital modules. I bought the Danish Gato Audio 400-S then they build their own analog input output sections ,and International rectifier developed a super high speed switcch8ng for their 2 high power Mosfets my integrated sounds like a very sweet SS- Tube combination . Of course I upgraded the fuses ,and put a very good Oyaide Sunami Power cord and in processs of matching the wiring throughout. VH Audio has a Excellent Wire Thea Cotton centercore are multi Litz Small Wire awg21 solid core Upocc solid core Copper and thin porous Teflon which is the closestdielectric to air. Incredible wire, I did the whole Xover and cables ,speaker cables , now Amplifier power supply, and Loudspeaker terminals ,also to all replace any Brass to at least high purity phosphor Brinze or gold over Copper RCA Connectors,IEC input ,and Speaker connectors . Over 70 % of companies use Gold over Brass rca, IEC, and speaker terminals, Not Good but true.i sold audio for many years.. Itis a amazing upgrade the conductivity is 3-4x better ,which is a fact . just lookup metals resistance ,conductivity,and great wire throughout creates a fantastic synergy, I also use premium Xover parts and bypsss caps, and the Zobel networks I make for the back of a Loudspeakers is simple but effective ,and cost effective. if you or a friend is handy these are things to Strongly consider doing. You raise your systems potential at least 15% minimum is not more.
There’s a huge difference between a pre-amp and a power amp.
Correct, two different active Class-D subs and one SR reciever I’ve had on my HT system, have eventually blown their smp caps, and in a chain reaction taken out the class-d amp as well, luckily new plate amps were available, and at trade price, just cost effective to repair for myself only, no way for a customer, they would maybe have been better of as Ricev’s said junking it and buying a new one.
Electrolytic caps aren't famous for having exceptionally low ESR, but
they're the only technology that's compact enough to provide the current
capacity required. The sub-optimal ESR leads to internal heating of the
capacitor. The heat dries them out, the ESR rises, that causes them to
make more heat, they begin leaking electrically, and they eventually
just short out and start frying silicon.
David Bernnig used a switching supply in his TF-10 preamp which was made in the early 1980s IIRC. I have a customer in town with one of those and it has the original filter caps in place- very much alive after all these years. He seems to have sorted it out- those filter caps run cold to the touch. The first statement in the above quote is false- electrolytics are the only technology that's compact enough to provide the **storage** capacity required, not current.
SMPSs don't need a lot of capacity because the switching frequency is so much higher. This means that a much smaller capacitor can be employed than in a 60Hz supply. I know some SMPSs did have some problems in the early part of the 2000s, mostly on account of some Chinese caps that were failing not because of switching frequency so much as the parts were just plain defective.
I spend a lot of time in research how our emotion works regarding music.
When you compare different amps who play in Class A, AB, D or G they still are different regarding the aspects/properties of sound. And most still are not able to reveal all the different aspects/properties of sound.
When you look inside the most new amps of all different brands. The facts proof that manufacturers are using cheaper parts these days. When a market is decreasing you need to find a way to make your products still profitable.
So they start to use cheaper parts, and this is what we see now in almost all new amps. When we audition them most of them create a very limited level in diversity (layering) in sound.
This means you can sit in your chair and even after 4 months you still have never felt any kind of emotion of your music. For us as music lovers it is sad to see that how poor most products are these days.
The manufacturers have not the insight and knowledge to create better products so more people would become interested in new audio products. When we go to an audio show I am with my 46 years of age one of the more young people overthere.
It is 5 before 12 and we are aware that something has to change. Trial and error is also responsible for the fact that audio is a decreasing market. The facts proof that the quality people can get by trial and error is very limited.
Hello Bo1972, you made your point abundantly and eloquently.... We get it... No need to beat a dead horse. Please rest your case... Or start your own thread.
Many people see audio as a hobby and even believe (the same way as you believed in Santa Claus when you were little) on assuptions that you only can choose your personal system.
But the facts proof that almost all human beings cannot choose their own system the right way. And even this can be explained based on facts.
Sound and also music contains of many different aspects/properties of sound. When you are listening to your system most people can only distinguish 1 till 3 different aspects/properties of sound at the same time
But....when you want to make the best choices you need to be able to extract 8 different aspects/properties of sound with 1/10 of a second. There are not many people who have this level in insight.
This is why the whole world is doing audio by trail and error. It is based on the limitation in insight of human beings why it is still done by trial and error.
Many people who see audio as a hobby are their whole life busy with changing there system. They listen to it and often they focus on just one aspect/property of sound at the same time.
I give an example. (I had the same conversation with hundreds of people who see audio as their hobby)
You miss control and layering in the lowest frequencies. Most people will often try different cables to hope to solve the limitation they hear in the low frequencies.
After time they find a cable what gives a much better controled low freq. So they are happy and buy the cable what ’solved’ the problems.
They did choose this by trial and error. Based on the fact they they all have no idea which properties they took out by replaceing the cable for another one. Like they also have no idea which properties they brought in by the new cable.
And now you will read what sounds very familiar to you all. Because I saw the same kind of reaction hundreds of times before. After a few weeks they found out that the high frequencies are a lot less open than it was before.
So it all starts over again. And they will change one part for another one. It will never solve all your problems. Based on the fact that their choices will always be made by trial and error. So there never will be a real foundation.
The biggest limitation in audio is that most products do not own all apects/properties of sound. This means that they will always create a limitation in each single audio system you use them for.
It does not make sense which combination you will make, they will always create a limitation.
teo_audio If GaN acts like a V-Fet or a SIT, then they might be on to something.
And they are, the EPC guys (
Alex Lidow ceo ect) who invented the GAN, also invented the power mosfet many moons ago and sold the rights it to the world, for the moment only Technics are using the GAN with their limited availability $20k SER-R1 amps.
Trail and error is doing audio at the level of a child.
So many people asked me what do I mean with this?
I will tell you. Children will face many situations that they have no idea how to handle. Because they do not know the new situation and what the best way is to handle? So they react and hope it will work out ok.
I asked many people who work in audio for a long time about how they make their choices.
I will give you an example.
In 2017 I was in an audioshop and the person started to work in audio also in 1998 like I did. He received a new loudspeakercable and he wanted to test it.
So I asked him: this system overhere you will use and the loudspeakercable I see you will change?
He said yes.
So I asked him: which properties of sound you will take out when you take this loudspeakercable out?
Each audio product owns it’s DNA. I learned to extract the full DNA of each single audio product in any system. Because I had a mindset in 1998. I was aware that when I want to understand why each single amp, loudspeaker, source all sounds so different. I need to know the full dna of each individual part.
He said; I have no idea.
So I asked him; which properties of sound you will add when you replace it by the cable you want to test?
He said; I have no idea.
So I asked him; When you audition your system or the system of a client do you know why the sound and stage (only 2 aspects/properties of sound) is what you hear?
He said: I have no idea.
So I said: then you will never understand what you are doing.
It made him realize that he makes choices pure without any kind of foundation. So I said; when you do not know what you are doing, you are just like a child who does not understand how to make the right decisions.
And he said; you are so right.
People need to learn to think further. Trial and error is the main reason why most audio systems all sound so limited. Based on the fact that they are all incomplete. This means that they lack different aspects/properties of sound.
Each individual property of sound can influence your emotion. That is why each audiosystem what can reveal all the details and aspects/properties of a recording will always be a much more emotional and intense experience than any incomplete trial and error created system. And again this can be proven by sound.
The emotion of the music you always will find on the recording. That is why a system is needed that can reveal all the details and different aspects/properties of sound.
Some dealers want you to believe this, but I couldn't disagree more. A "shootout" is the worst way to evaluate an audio component, because what may appear at first
to be impressive or revealing often - over time - reveals itself to be distortion or some other anomaly. There's no substitute for relaxed listening over time in a familiar system, imo. That's when a component's true nature is revealed, and this approach to choosing components has served me well. "Shootouts" are for audio cowboys.
Audio is all about shootout and comparing. And the best one will always be chosen. You need to find the best one in each single price range.
So far I never auditioned a class D who was the best in it’s price range. All the ones who are less than the best one have no meaning in our world.
When you do not understand sound and music you will never understand audio either . Over 99% van all human beings don’t understand that much about sound and music.
I had conversations with many people who work in audio (just like me over 20 years of time). They all had to admit that their insight and knowledge was very limited.
I asked them all many different questions they could all not answer. This made them realize that they own a very limited level in insight and knowledge regarding music and sound. This is needed to understand audio.
The fact that audio is done all over the world by trail and error. Proofs on facts that the awareness of human beings is very little developed. Based on the fact that trail and error has no real foundation. When I talked about this with many people who work in audio. They realized that they cannot extract the dna of each single part in an audio system.
So you never will understand what you are doing. And it is just audio by gambling. They all agreed that there was no way to understand why the sound and stage(these are only 2 aspects of sound) is what they can hear. This proofs on facts that there is no foundation. You always need a foundation to understand exactly what you are doing.
Knowledge and insight is something you need to develope yourself. But....most people in audio are all just like parrots. They use they words they read from articles. Or they say the things distributers or manufacturers told them.
I give you an example; We were at the first presentation of the B&W 800D3. The person who did the presentation said: B&W did change over 800 parts compared to the former series2.
So we asked him a simple question: can you tell us some of those changements? But he could not, and he realized that he was only telling us a story from a paper.
Whe you let people hear instruments and voices in real, it becomes clear that most audio products sounds a lot different. This proofs on facts that most manufactures know little about sound and music as well.
Because if they would have known a lot about sound and music their products would have sounded a lot different. So what is needed to create audio products who sound more realistic an natural?
Yesssss research and knowledge and spending time how music and instruments sounds in real.
If GaN acts like a V-Fet or a SIT, then they might be on to something.
The non linear gain curve of a modern transistor will generate odd order harmonics, which is where the problem in audio lies.
A SIT or V-Fet, produces predominantly even order harmonics, which is tied to possessing what is principally a linear gain curve. More akin to a tube. A triode tube, specifically. This is critical. Big time critical.
Class D, as it stands, produces what is predominantly odd order harmonic hash, which is filtered.
The shape of that odd ordered hash is mistaken for detail, as the components of it (mix of odd ordered harmonics) meander around (shift and change) in the presented mix.
I heard it for what it was the first time I head a class D amp, and it is there in all of them. Garish, faulted right to the emergent core, unlistenable. For me, that is....as I heard it and recognized it...that it is totally against the aim of audio technology, in my view, hearing and understanding. To take the worst and unwanted part of what solid state devices do and make it the ENTIRE waveform. Jebus.
This is mostly testable in a finished item...as Sony did it right and made a class D amp back in the day, with SIT or V-Fets as the output devices.
newest class D amps are so good and so cheap that you could just throw them away
What a wonderful throwaway society we now live in when we can even consider that statement as not only being relevant but likely the truth. Very sad reflection of todays mindset and the times.
You must have a verified phone number and physical address in order to post in the Audiogon Forums. Please return to Audiogon.com and complete this step. If you have any questions please contact Support.
