I thought it was time we had a pro- Class D thread. There's plenty of threads about comparisons, or detractors of Class D.
That's fine, you don't have to like Class D amps, and if you don't please go participate on one of those threads.
For those of us who are very happy and excited about having musical, capable amps that we can afford to keep on 24/7 and don't require large spaces to put them in, this thread is for you.
Personally, I think it's a horrible thing to price out a product based on component costs.
I think everyone would be horrified if we did this consistently across audio.
There's more to a high frequency design than the cost of the transistors. PCB layout must be done meticulously, and test failures common, so R&D matters.
Still, having said that, Class-D amplifiers are quite good already. Better than some Class A amps, worse than some Class A/B.
If there are actually audible benefits to GaN based amplifiers I look forward to hearing them.
GaN transisitors don’t cost any more than mosfets. People are charging more for GaN amps because it is the latest buzzword and they are first out so they gouge you. The EPC GaN fet recommended by EPC for audio use costs $1.05 each at 100 quantity. Hardly expensive. At the most 4 per channel....so that is $9.
GaN amps will be available from China for a few hundred dollars.....I have no doubt. However, they have to design the circuit from the ground up.....so will take a little while to come. The big manufacturers are slow and conservative (Hypex, IcePower, Pascal, etc.). It takes a sledgehammer to get these guys to try something new and then it takes years for them to develop it. It will be just small companies for awhile with GaN amps.....but hopefully, the big guys will get on board. TI and Infineon, etc. make class D amp chips as well. Maybe they will be first to come out with a GaN version......then you will see things like this:
Hello All, I was long hoping to evaluate the Rowland Daemon 1500W
Superintegrated amp. Could a class D integrated fulfill my yearning for sonic nirvana, or would Daemon leave me pining for the wonderful music of my separates: Rowland Aeris DAC fed by the ultra-capacitor-based PSU external power supply, driving my beloved M925 monoblocks? Eventually, a Daemon review unit was delivered on February 28th. I Started
break-in the following day, and have been scribbling my listening notes since…
The writing project will continue for at least a few months, until the
device has stabilized, and I have exercised several of its many input and
output features. I have been waiting for a long time for this 99Lbs single box
critter. It is Jeff Rowland’s integrated statement. The DAC + Preamp + 1500W/8
(2500W/4) dual-mono power amp in a single chassis measuring 17.5” x 15.25” x
9.5” is sounding amazing after just a little more than a couple hundred hours of break-in.
Discovering the phenomenal musical beauty that Daemon produces is being a fascinating experience… Already I am stunned by Daemon's power reserve and unreal tonal grace. Join
me to chat about my adventure with this integrated flagship around its new Audiogon watering-hole:
I never heard one. Ended up with the NAD equivalent and very happy. They use a hybrid , almost like a Class H, Class D and Class A in one, designed by Hypex. No, the new transistors won't make anything obsolete, but sure will make things more expensive.
I remember the Peachtree importer a friend of mine here in Australia demo’ing me a pair of midrange floor standing Focals to be our Audio Clubs "house" speaker, which he also imports, as well as Krell amps.
He was using the Peachtree at the time because he had no Krell’s handy, and quietly said to me the Peachtree isn’t very good, you should hear these Focal’s with the small integrated Krell feeding them.
Hi guys is this thread redundant? im thinking of the Peachtree Nova 150. Any owners? im wondering why they’ve gone back to Ice for this line. Didn’t they use Hypex previously? Also won’t eGaN make all these redundant quite soon? Cheers
celander: "
I suspect some type of class A-class D hybrid will likely be the future for all class D topologies."
There are currently class D amps using the topology of both transistor and tube analog class A input stages combined with analog class D switching power amplifier stages. I've never auditioned any of these amps but did read a very good professional review on 6Moons about the French DeVailet solid state hybrid integrated class A-class D hybrid.amp. The reviewer loved it but it was uber-expensve like most of the best traditional amps are and always have been.
during the past century and possibly for another century. Perhaps the most significant aspect of the many good class D amps is their affordability. From my perspective, the egalitarian nature of class D technology is a beautiful thing, bringing extraordinarily high sound quality to an increasing number of individuals' systems that otherwise would not be able to afford and experience it. I'm hoping the future of class D topologies is a bit more interesting than just relatively expensive hybrids. The inventor/designer of both Ice and Hypex NCore class D amp module technology, Bruno Putzeys, has stated he's able to design class D amps that sound like any traditional class A, tube or hybrid amp topology desired. I wonder if he could design an affordable class D amp that could mimic the sound characteristics of the best current and past examples of traditional amps, along with the best example of independent class D amp sota efforts, that is user selectable. A guy or gal can still day dream, right?
@atmasphere can you give us any information on when your Class D (not digital) amps might be ready for prime time? Will they be stereo or mono-blocks? Estimated price?
maplegrovemusic They are active with class d amps inside . These are in no way bright or fatiguing , things I have associated with older class d amps . Looking to find out how and why this could be ?
This may help, but the reviewer found it
a bit dry and lacking in harmonic complexity and bloom in the upper midrange, a bit dry in the mids, and maybe even somewhat aggressive on top. It's one of the first, commercial Class-D that came after the original Class-T (Google these also as they only used N channel fets which allowed in some cases a higher switching frequency) The 18 year old Sharp SM-SX100 Class-D, if you look at the 4 ohm frequency response it's already starting to roll off the high frequencies at 2khz, and the simulated speaker load is not much better. https://www.stereophile.com/content/sharp-sm-sx100-digital-integrated-amplifier-measurements
I don't find good digital amps bright or fatiguing today.
In the late 1980's I was listening to some digital amps that sure were though!
I don't know how old the B&O/ICEpower designs are, but that's what I listen to every day now. :) It's quite possible the speakers, designed as integrated wholes, eliminated issues with the rest of the Class D crop.
I will say that the Class D amps I was listening to wwas through entirely different speakers, TAD pro studio monitors from the time, so that could have been a horrible match overall.
This is probably over simplifying or incorrect, but maybe their maker voiced the speaker to the internal amps? Or did the amps only power the bass drivers?
@erik squires Eric , I purchased a used pair of Bang & Olufsen Penta 1 loudspeakers a few months ago on craigslist. They are circa 1989 . They are active with class d amps inside . These are in no way bright or fatiguing , things I have associated with older class d amps . Looking to find out how and why this could be ?
I love my Audio Alchemy DPA 1, which is said to be a hybrid, due to an FET input stage, I guess. Last night I swapped out a silver over copper Surf XLR for an old PS Audio (mid model) and was floored at the much needed warmth that was hiding in the amp
There’s a vast number of class D amp owners literally throughout the world that have absolutely no doubt about whether their amps are extraordinary performers in their systems. Yes, the great majority of them have switching frequencies in the vicinity of 500 KHz and may not possess the latest and fastest FET transistors in their output stages. Most of them are probably unaware of this but likely wouldn’t give a hoot if they were aware because they sound so incredibly good in their systems. The owners of one of the many current or recent crop of extremely good class D amps just hear the obvious; their amps have very low distortion levels, dead-quiet background noise levels due to very high signal-to-noise ratios, excellent frequency response throughout the entire audible range, very good dynamic range, very good channel separation along with the ability to handle very low speaker impedance levels and deliver more than enough power to properly drive any speakers. Additional class D amp benefits include small size, low weight, high electrical efficiency that results in low electricity consumption and very little excess heat and all at very affordable prices. What’s not to like, right? Despite all the benefits of good class D amps described above, you continue to suggest avoidance of these amps until they utilize switching frequencies in the mega-Hz range and the latest and fastest generation of super-fast FET output stage transistors . Will higher switching frequencies and faster FETs enable class D amp performance to get even better? As a user of several exceptionally good class D amps of recent vintage, I find it somewhat difficult to imagine how their performance could significantly be improved but I’ll keep an open mind until I give one a good listen in my system. Until then, however, I. would advise anyone considering a class D amp that it makes little sense to wait for possible class D amp perfection. Nobody needs to deprive themselves of high quality sound by making the same mistake that georgehifi consistently and inexplicably insists upon: making perfection the enemy of the extraordinarily good.
I understood your input to me as not trashing class D designs, per se. They differ among themselves as much as designs within categories of other topologies do. Sometimes the output devices (in this case—for our discussion—Duntech and Dunlavy SC speakers can reveal and distinguish those designs as being better matched over others, whether class D or class AB (tubes, for example).
Even folks here who rave about their preferred designs within the class D family would concede that point. Their raves are within a given reference context.
Oh, I don't mind that. I'm not hear to convert anyone.
Why then interject with personal backlash, when
celander and I, were just talking about amps that are most capable of driving the Duntech Sovereigns, and I just happen to see and post a link to amps that can and couldn't, and it just happens that Hypex N-Core Class-D couldn't drive them. Here it is again as it's lost now on the other page. Duntech Sovereign's suitable amps that drive them.
Oh, I don't mind that. I'm not hear to convert anyone.
But I think it shows a great deal of class when you speak your peace and then leave the subject alone for those who are contributing in a positive fashion.
As is the case with most of what we are taught as our understanding, we must be willing to surrender our understanding to gain insight into truth. There will always be those who refuse to surrender their understanding to learn truths. And that’s ok. We just need to acknowledge it for what it is.
No matter how nicely you ask George to start his own nay-sayer’s thread, he’s always going to share his impressive collection of articles about how planes can’t fly.
No sir, they are too heavy and completely unreliable. Plus, you will fall off the edge of the world if you go too far.
God help those of us who want to talk about how much we like Class D, because there is George telling us we are wrong. George would skip his own chemotherapy treatment to come and tell us this.
Pretty sure the Dunlavy SC’s didn’t vary much at all from the Duntech speakers. The SC’s have a nice impedance response (6-ohms). The Spectron Musician III amp has a fairly low output impedance (< 0.1-ohms) and a high damping factor (500:1).
celander He later told me in ~2006 or thereabouts that John Dunlavy used the Spectron amps to voice his SC series of Dunlavy speakers.
https://www.stereo.net.au/forums/topic/49395-why-are-some-speakers-suited-to-valve-amps/?do=findComm... " I’ve set up Duntech Sovereigns, it is abundantly clear that John Dunlavy designed them to be used with the very lowest output impedance amplifiers available. They don’t even wake up when connected to even quite prodigious valve amplfiers. Even highly capable amplifiers like the ME850 barely get them under control. It takes something like the big Krell monos, or an ME1400/1500 to make them sing."
I just spent the last hour catching up on this entire thread.
@erik_squires Well done, my friend! You’ve navigated a wonderfully positive thread.
@georgehifi Great contributions throughout. I very much would like to have seen the YouTube videos from EPC regarding their new class D modules for audio applications. Alas, they were blackened out on my iPhone. But I did enjoy your shares about new Gn-based transistors having higher switching frequencies. And your Aussie round table thread from high-end designers was special. Erik might complain about your rain, but it’s welcomed by me, as it seeks to clarify where the class D tech needs to improve. The opinion of Nelson Pass is a good benchmark to base all future commentary. 😂
@atmasphere And yes, the motivation for class D amplification was all about increasing dynamic headroom—avoiding clipping. Yet, as @atmasphere will point out, it’s the first Watt that matters the most and where the class D tech really needs to focus.
As a teenager, I auditioned an Infinity SWAMP, which was a class D amp the late John Ulrick designed and based upon tech that John and Infinity was awarded a US Patent for. I bought a Digital One amp from Spectron Audio (apparently now defunct) in 1997 or thereabouts. I spoke with John numerous times about his topologies over the years. He said the SWAMP design was ahead of its time because the high speed switching transistors really didn’t exist during the 1970’s to make the amp stable. That all improved later in the 1990’s. He later told me in ~2006 or thereabouts that John Dunlavy used the Spectron amps to voice his SC series of Dunlavy speakers. He said that my SCIVa’s mated with the Spectron amp was a magical combination. I only saw one post here from a contributor who had a Musician III amp.
So my question is: how do the Spectron amps stack up in the mix of present class D amp technology? Back in the day, it was a 300WPC 8-Ohm) stereo amp at $2500. I’d appreciate personal accounts rather than speculation.
You’re likely getting no responses to your request for sound quality reports on the 2 newer 52X and 54X ATI class D amps because you’re only reaching members who own one of these specific amps AND happen to still be following this long running thread. You may get more responses by starting a new separate thread.
Sorry, I’ve never auditioned any ATI class D amps but I can verify that the D-Sonic M3-600-M class D mono-blocks I own are excellent amps. However, I bought mine about 4 years ago when they utilized Anaview/Abletec ALC1000-1300 class D amp modules. Anaview discontinued the ALC100-1300 modules in 2014 and I believe the current D-Sonic M3-600-A monos utilize the newer Anaview AMS-1000-2600 modules. I think D-Sonic only uses Pascal modules in their top of the line M-1500 mono-blocks. Both Anaview and Pascal are Scandinavian companies and their class D modules differ from most by combining the amp section and the switch mode power supply (SMPS) on the same board. Most other class D module design/manufacturing companies, such as Hypex-Ncore and B&O-Ice, offer the amp sections and SMPS as separate products on separate boards.
I asked D-Sonic’s owner, Dennis Deacon, back in 2014 about the sonic differences he noticed between the Anaview ALC-1000-1300 and AMS-1000-2600 modules and here was his response:
" Tim,
I have been shipping amplifiers with the new AMS1000-2600 modules. The sonic differences with the previous ALC1000-1300 are very subtle with most source material. They do have a more natural resolution of detail and a more natural impact in the upper bass to lower midrange area. This is where most big dynamics are heard such as percussion, cellos, baritone and bass horns."
Here’s the name of that thread that you might find useful and interesting:
So, with all of this Class D talk, where to the new ATI 52X and 54X rate in the scheme of sound quality? How do they compare to the D-Sonic and their Pascal modules?
Well I bought a NAD D3020V2 and have to say pretty darn impressed for the money.
Great features include a built in MM phono stage, an additional analog input,a toslink input and a spdif input. Another nice touch is a subwoofer output. Add all that to its tiny form factor, if you cannot find room for this then there is something wrong!
Sure 30wpc is not going to rattle the roof beams but paired with Epos ELS3 speakers it plays louder than I need it to. Oh headphone output as well so very hard to criticize for a bedroom unit or third system which is where it now resides.
$300 shipped as a factory NAD refurbished unit with full warranty.
Thinking of buying the d3020 for my daughter's room and pairing with a pair of epos els3. Sources would be a tt as I see the v2 now has a mm phono input and a PS3 via toslink.
So, with all of this Class D talk, where to the new ATI 52X and 54X rate in the scheme of sound quality? I have read great articles saying how wonderful they are but what about people who have actual experience with them who don’t work for a paid magazine?
In a home theater application will there really be much difference than say running an older parasound or anthem amp?
@erik_squires FWIW the phrase above is a marketing thing. It means that the amp has a DAC as its input, but the amp itself is actually analog, like all class D amps are. IMO/IME marketing terms like this tend to confuse the marketplace.
@tomcarr ’PWM’ stands for Pulse Width Modulation. Such an amplifier usually has something like a triangle wave oscillator in it. The incoming audio is compared to the triangle wave and this determines how long the output devices are either on or off. The switching frequency (which is otherwise determined by the frequency of the oscillator) is then stripped from the resulting signal and what’s left is the audio.
Tom - Yeah, I’m using an NAD D 3020 in the bedroom. It’s a hybrid Class D designed by Hypex, so it runs a little warmer than you’d expect. It’s really quite nice.
One thing I’ve learned recently is NAD is using 3 different types of Class D:
1 - Direct Digital 2 - Hypex Ncore 3 - The Hybrid approach they used in the 3020.
It would be interesting to compare them side by side! I will say that while I am a fan of Class D in general, I’ve never heard a PWM amplifier I actually liked the sound of. I suspect they get the feedback (if any) quite right and can’t solve the output filter issues well.
Hi Erik, thanks for starting this thread. Another + for class D. Bought a NuForce integrated for a bedroom system. It sounds unbelievably good considering its cost. Without regard to cost, it sounds quite good. A little on the warm side, no sibilant hash, non-fatiguing, pleasant, musical. What more could a sane, rational person desire?
Exactly like the A21 and A23, the the JC1 is high-bias Class A/AB.
(model names in sentence above are links)
Good amplifiers.
Have not heard the JC1, just the A23 and A21.
I have to agree, "class warfare" in this context is meaningless and with little to no supportable evidence. This is what showrooms are for though. Buy what you like listening to, which needs no justification.
My Lyngdorf 2170 has replaced a BAT VK600SE. Am I happy with what I hear? Heck yes although I believe the room perfect system may have just as much impact on my listening as the amp itself.
Also looking at buying a small Bel Canto integrated for my daughter.
The class warfare should really just end. There are very good and very bad amps of all classes. Furthermore one man’s bust may be another’s bounty. That’s how the world tends to roll in general. Deal with specifics not generalized statements that cannot hold true in reality. For example if I designed an amp it would probably suck no matter what Class because I am not an amp designer. Many are very skilled amp designers however and make very good products using their own unique skills to master technology in different ways. Those people are entitled to think their design is best but not at the expense of others. Each buyer will decide for themselves which is "best" for them using all the unique senses God granted them.
Give it up already!
Personally, I’d say Bel Canto Class D amps are one of the best things that ever happened to home audio in my house! They are marvelous sounding modern masterpieces of technology and meet my needs perfectly!
It seems clear @bluesy41 doesn’t have a clue about Class A Amos. You can’t make broad statements about any amp Class. There are Class A amps on Amazon starting at $500.00 and some of them they sound pretty bad.
To both of you. The Parasound Halo JC1’s in high bias class-a (which is no more than around 20w of A) sounds magnificent, and will blow away any Class-D full stop!!
Parasound Fatiguing?? Hahahaa. Some of the warmest A/B amps out there. Run Class A most of the time. And yeah, I've heard _some_ pure class A amps they beat hands down.
Unless of course you measure sound quality by money spent. Then of course, only Class A will be pricey enough for your ears.
No offense Erik but I find it hard to believe you can compare Parasound to any highend class A amp for musicality. I get it you love it, but let’s try and be objective. Parasound is a step over Adcom and 20 minutes from extreme fatiguing.
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