I am certainly biased by my lifetime final amp being a Class D. But I know that after 30+ years of development, Class D seems to be on a high plain. I know there are now many, many companies focusing on Class D and, maybe, a good handful already as good as it gets. My Class D amp is as smooth and beautifully musical as a great tube amp and as punchy and detailed as a great SS amp. I am satisfied and done with my search. A class D amp has effectively taken me off the amp merry-go-round. It’s about time after 50 years. And, for me, this Class D is a milestone. Will all other classes of amps fade away?
It will be interesting to see if manufacturers start to migrate away from less 'environmentally-friendly' amp topologies. As executive leadership, and designers, become younger in these companies, they might make the decision to focus more on 'greener' designs like Class-D. And, there is the possibility that environmental agencies start pushing for such a thing, just like has been done in the auto industry. If tax credits are offered for R&D towards this, that will further incentivize companies in the green direction.
However, just like with cars - where there will always be 'classic/muscle car' enthusiasts - there will also be Class-A, A/B, tube amp enthusiasts...and hopefully repair techs to service them ;)
Of course, we're probably talking about decades, not years, but clearly there is momentum already occurring in this direction.
I’ll never own a D amp. Never. They’re built cheap. They’re all about low end sales. Tubes rule. There’s no shortage of tube amps to buy. I recently purchased a new KT-88 integrated, even though I already had one. So, as you see, I’d rather have two tube integrated’s than a single D amp. You lay down your money and buy whatever you want. No D for me.
Why does Class D attract these unsustainable blanket generalizations (e.g. @nseymour) while no one (well, virtually no one) would dream of making such universal claims w.r.t. class A or A/B?
You never know, maybe Ralph @atmasphere will design a switching tube amplifier. Ha
We've already done that- been working on it for the last 4 years. We're in Beta production right now.
If you think class d is better than class a or class a b you better get
your ears checked LOL they've gotten a lot better but they're still not
as good.
Instead of checking your ears, it might be more fruitful to check a different class D amp and see if you still say that. Class D, like tube amps or traditional A or A/B amps, are all over the map in terms of sound. Some manufacturers have sorted out what works and care about it, and others have not or don't care- same as its always been...
I sold my Pioneer 70 D class amp. And recently listened Marantz Reference Series PM-10. All Class D amps have power and clean sound but lack of richness and soundstage.
When someone tells me that both Nelson Pass and Steve Deckert are now designing exclusively in Class D, I will consider more. Until then I have 2 class D's and that is more than enough. Love the operating temperature of class D. Oh yea, I also love the operating temperature.
If you think class d is better than class a or class a b you better get your ears checked LOL they've gotten a lot better but they're still not as good.
Class D has definitely come along way. From my thinking it really has just made its way to be able to compete with A, A/B and the other variants. I believe that we can finally believe it when someone says "its that good". , but we will still always have good Class A, A/B amps to consider. Class D is no different than the others now. A good design along with good parts make a nice amplifier. We finally just have another product to consider at any budget looking for bang for the buck or recently, even to compete with the best. You never know, maybe Ralph @atmasphere will design a switching tube amplifier. Ha
I had two NAD Purfi units in my house and neither stayed long. Ran hot, glitchy and hardware issues.
Modern Class D amps like those from Hypex or ICEpower (used in many high
end brands) are simply excellent performers, musical ruler flat
frequency response, SN numbers that other amps can only dream of
achieving and they are respectful of power use and efficiency.
Heat and thermal cutoff is the real issue, as the power supplies can get excessively hot. Attaching finned heat sinks (ones with adhesive attach easily to flat heat shields) and providing sufficient air flow is crucial. Plus running hot kills performance. I've found AC Infinity fans with a Controller and a sensor work well and the speed is adjusted according to temperature. When the sound is not turned up the fans will be slow or stopped.
Most of you know I have owned the EVS1200 for almost 2 years; dual mono based on AS1200 IcePower modules, but highly tweaked by Ric. During this time my system has undergone a number of cable improvements, plus new speakers (Emerald Physics 3.4s). I had been using optical cable between my Oppo 105 and my Audio Alchemy DDP-1 + PS 5 power supply.
For some reason (probably read one of the AG threads) I began looking into coax digital cables. Prices run the gammit from < $100- > $1000+. I contacted AA who offered either WireWorld ($$$-$) and Pangea ($$). I also looked at DHLabs, but decided to buy the Pangea. I bought a 1.0m SE ($49.95) and immediately was amazed how much better it was vs the optical. I reported this on my digital cable thread. Someone responded that 1.5m sounds much better. Why? I don’t know. For sure the others were $$$s for 1.5m, so I ordered it from Audio Advisor ($59.95). It performed much better, as mentioned, but how many hours of break-in before it really comes on song? Last night was day 6 of connection, but maybe 10 hours of actual play time. I listened to Lyle Lovett and his Large Band, followed by Bonnie Raitt, Nick of Time (I have owned them both for ~10 years): they both sounded quantum levels better than they ever did, no matter whether I had an all tube system, or all SS with class AB amps.
Cutting to the chase, ones digital connection could be why some have negative comments about class D
OMG I see they also have a Premier XL $149 for 1.5m, so I'm ordering it now
I honestly think the Benchmark amp is the ...Benchmark.
Sure, more power would be good, but because of how it's designed, bridging mono actually works and doesn't degrade performance anywhere, despite what some grumpy old know it all gatekeeper keeps spewing on this forum.
I have tubes, which i love for different reasons...have had icepower, hypex, A, A/B...However, lately i'm having a hard time NOT listening with the Benchmark. Having such a quiet noise performance, no matter what the haters say, is very special and makes the listening experience different, in every good sense of that word.
This is the first amp i've had where i'm not tempted to sell and upgrade, for fear i'll miss the sound too much. Hands down the best i've owned, and I will probably grab another soon.
I purchased well regarded, highly recommend and reviewed Class D mono amps 1,000 watts of power and had high expectations but the Class D amps did not have the life, dimensionality, transparency and immediacy that my Class A SS amps had. With the Class D amps, the sound was flatter and much less engaging. So even though Class D amps may work well for many applications, IMO Solid State Class A amps produce better sound. And IMO, well designed tube amps sound even better than SS in terms of music.
are definitely making me think about class D. I don’t think I need a replacement for my class A/B, but I’d add a D due to the fact that they are tiny and run cool and easily could fit with my current amp.
Some mention "No Noise".. Where have you been? My 1971 and 1996 Audire Fortes have no noise. Neither did my 1985 Audire model 2, 1990's Sumo, 1970's Phase Linear 400, nor my old $50.00 garage sale Adcom 535. Well, actually I had to orient the Phase Linear plug with the correct prongs in their respective outlet holes.
They will not because people will seek out the best classic amplifiers and speakers when all the good new stuff is gone and find out that is where the best sound is anyway.
Stick with the facts. You claimed that i could not be getting good sound with my Class D and Wilson's claiming my Wilson's were hard to drive, don't muddy the waters.
Well..george has an MO of trying to cherry pick items to bolster his view.
You really need to get educated on this. Look at the paragraph direct above your last post, even he back down on the flagship Wilsons I mentioned that a Class-D can't drive to their best. And he cherry picked the ones that can, (Sophia, Sasha ect) because they have far easier loading that the Class-D won't be too taxed with🤦♂️
Well..george has an MO of trying to cherry pick items to bolster his view.
The Wilson speaker Sabrina X was not the Wilson in the conversation, he read in a rag that the X could give some amps issues and decides to bring it into the conversation but the X has nothing to do with the Wilsons i own and he accused of being hard to drive. Historically Wilson's have the reputation of being efficient and easy to drive BUT require the best in electronics to make them shine.
These companies that claim double wattage when impedence is halved don't
give the actual 8ohm measurement, which is usually a lot higher wattage
than their spec sheet has listed.
Our class D amps do 100 watts into 8 ohms and 200 into four. There is probably a slight difference due to the output impedance that causes the 200 watt reading to be inaccurate but its too low to resolve. But in reality the amp doesn't clip at 100 watts- it does so at 125 into 8 ohms but into 4 ohms it clips at 250 watts. So while your comment is true in some cases its not true in all cases.
You keep mentioning Wilson’s as being hard to drive, where does this come from?
For someone who "says" they’ve owned Wilsons, you are not very
au fait
or even interested in how they measure or behave, in particular the loading they present for amps to see.
While its true that the Wilsons have a low impedance in the bass (the Sophia and Sashas being the ones of their more recent lineup with which I'm most familiar) they really are reasonably efficient. When our MA-1 was hooked up to the Sashas (a friend of mine in town had them) the meters on the amp barely moved but there was plenty of volume. You have to take the drivability into account as well as the impedance. Our class D amps regard the Wilsons as a benign load.
I can second the comments by those who have/have heard AGD amplifiers. My bias towards Class D has been negative -my Bladelius Ask has a ‘green’ mode using a Class D module, which is flat and harsh compared to the ‘performance mode’ which is ClassA/AB and very good. New speakers in another system are higher efficiency ( Viking Acoustics Berlin), and the LSA Statement (hybrid integrated) driving them sounds wonderful, yet is simply too noisy. I hear the tube hiss at lower volume and can’t ‘unhear’ it. My search for a replacement led me to the AGD Audion, which I had the pleasure to listen to at Ocean Way Audio in LA. I found everything stated about these amps, also in this thread and particularly by @atmasphere, confirmed. These are superb amps. Tube like sound and dead quiet. It does of course help when one of the most accomplished recording engineers in the industry endorses a product. In my mind, this is not a mere variation of a theme, it is a discrete innovation when you consider form factor and performance. I ordered a pair…
Even the big high bias amps built with BJT's can't do it. When stereophile measures them their 8ohm full power measurements are a lot higher than the spec.
These companies that claim double wattage when impedence is halved don’t give the actual 8ohm measurement
Usually if they don’t, they are hiding something. Stereophile does for Class-D if you read the Lab Tests on them and that’s usually is in the negative. But even Stereophile doesn’t usually do 2ohm testing on Class-D’s as they are usually pitiful, when compared to the good linear solid BJT state amps for putting out big (doubling watts) current.
These companies that claim double wattage when impedence is halved don't give the actual 8ohm measurement, which is usually a lot higher wattage than their spec sheet has listed.
You keep mentioning Wilson’s as being hard to drive, where does this come from?
For someone who "says" they’ve owned Wilsons, you are not very
au fait
or even interested in how they measure or behave, in particular the loading they present for amps to see. And they have many models that are in that same low EPDR loading bracket.
From HiFi News Lab Report Impedance phase is quite well controlled but still the EPDR falls to a low of 1.2ohm/67Hz, with further minima at 129Hz (1.8ohm) and 410Hz (1.9ohm). So the Alexia 2 presents a challenging load to the amplifier, albeit not so much as its predecessor Mk1 (min EPDR 0.9ohm!!!!).
Things always get better....I remember when the new craze was introduced ...CD. The sound was awful, until it got better. If you live long enough there will also be something better waiting in the wings. Digital can be excellent, but excellence comes at a price as does everything.
@invalid.FYI. These guys claim that wattage doubles (close enough) at 4ohms.
Pathos Classic MK III
Specifications
Type: Integrated amplifier in Class A/AB, hybrid circuit with input tube stage, bridgeable Output Power: 2 x 70 W @ 8 Ohm, 2 x 130 W @ 4 Ohm, 180 W @ 8 Ohm in bridged mode (mono) Inputs: 1 balanced XLR, 4 unbalanced RCA Frequency response: 2 Hz - 100 kHz THD: <0.05% Signal/noise ratio: 90 dB Input impedance: 100 kOhm
Pathos LOGOS
The Logos uses MOSFETs in the output stage, known for their tube-like
transfer characteristics, in a design that attempts to come sonically as
close as possible to Pathos’ patented InPol circuitry. InPol is the
only amplifier design, hybrid or solid-state, that gives the full glory
of a tube amplifier but with control. Look at the numbers: 110 watts per channel into 8 ohms, and an amazing 220 watts into 4 ohms, with full bandwidth
georgehifi Next you’ll say an OTL of Ralphs can drive those Wilsons to their best properly, because they too will stay stable into them and not oscillate.🤷♂️
atmasphere The sales manager of Wilson had our amps for many years. FWIW our OTLs are inherently stable and will not oscillate with any load or input signal condition.
Dream on sunshine, were talking about driving the Wilsons mentioned here. Trust you to try to skew it around to make out that your OTL amps could even come close to driving these, the hardest of Wilsons to drive (Always looking for the self promoting angle)
Next you’ll say an OTL of Ralphs can drive those Wilsons to their best
properly, because they too will stay stable into them and not
oscillate.🤷♂️
The sales manager of Wilson had our amps for many years. FWIW our OTLs are inherently stable and will not oscillate with any load or input signal condition.
they are fets, and fets can’t do doubling of 8 to 4 to 2ohms (current)
like complimentary bi-polars (bjt) can do like in the the Gryphon
Antillion, bigger Krell, D’Agostino Boulder, etc etc etc
This one gave me a good chuckle- its so ridiculously false as to be funny! This statement ignores a simple fact about GaNFETs which is their ON resistance is one of the lowest values of any semiconductor.
One reason I bought AGD is because I was convinced that they stood apart from all other Class D. That all the others used variations of existing technology (chips).
It certainly helps when designing a switching amplifier to have also participated in related patents to switching transistors as Alberto has! But if you want to know why his amplifier sounds right, take a look at the distortion signature he shows on his website. If you look at the values you'll see that its not particularly low, but what is important (and IME arguably more important that *how much* distortion you have) is that the signature is what you want to see to prevent the amp sounding harsh. Here's the link https://agdproduction.com/audion/ scroll down and click on either of the THD images. You'll see that the 2nd and 3rd harmonics predominate. These harmonics are nearly inaudible to the human ear and because they are so prominent, they mask the higher orders (which otherwise are audible usually as harshness and brightness). This distortion signature looks very similar to that of our OTLs (although we show more 3rd and less 2nd due to our differential design). This type of distortion signature will cause **any** amplifier to sound smooth and organic. The lower the distortion the more detailed the amp will be without also being bright.
I've said many times that the differences we hear in amplifiers has more to do with what distortion we can hear and what distortion that we can't. This is more important than output impedance because the ear has a tipping point where tonality generated by distortion gets more attention than actual frequency response.
Class D amps can have a signature like this because the errors (non-linearities) in the encoding scheme and the dead time requirements (if handled correctly) tend to result in lower ordered harmonic production. (There is more to it than that of course...) In a nutshell this will cause them to sound like a state of the art tube amplifier that acts as a virtually perfect voltage source.
If you are pragmatic as a designer you know that you can't make an amp with no distortion :) The savvy designer will thus see to it that the distortion that is present is innocuous and this is a good example of how that is done.
They can come close if good, like the BJT ones I mentioned., Where many Class-D go backwards! instead of trying to double, if independently measured into 2ohm from the 4ohm wattage, that shows just how current limited they are.
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