Although not Class D, the Chord Ultima Line uses a switching power supply and runs cool. I think technically they are Class G or H but they are phenomenal sounding amps. I would certainly put them up against other amps in their price tier and they will be quite competitive. Given the flagship Ultimas are $69K....
Class D amps that are superior to all or most?
Recently, I have heard about some Class D amps that may be close to the best there is regardless of class. Certainly, this technology has been in development for decades. The main issue has always been the switching power supply. In this regard, I have taken notice of AGD. They have created a whole new power supply that “switches” at a frequency 100 times the normal silicon based MOSFET. The designer uses a gallium nitride based PS. Interesting, it is enclosed in the KT88 glass envelope that sits on top of his amps. I am aware of two more pricey amps that seem to be also at the top- the Solution and the Merrill. There must be others that compete for the title. After my thread, “Is there a SS amp that can satisfy a SET guy?”, I am still on the quest.
Don’t want to spend $50K!
Don’t want to spend $50K!
297 responses Add your response
I have owned the AGD Audion amps for about a month now. They sound great i was a SET guy and the AGD's bring the best of SET and SS without the past flaws of class D. AGD offers a trial period, i did this and had all intentions of sending them back but they surprised me at how good they were so i bought them and they continue to get better. Take the trial as i did and find for yourself it`s worth it. |
To most Class-D's Technics SE-R1 https://www.technics.com/us/products/r1/se-r1.html Technics SU-R1000 (maybe) https://www.technics.com/us/products/reference-class/integrated-amplifier-su-r1000.html But they probably still don’t quite reach the sound of the very best solid state high bias linear amps. Cheers George |
Underwood HiFi was launching a 200Wpc GAN amp for $3000 under the LSA brand that was supposed to bow around now so might be worth checking out. Also, although I haven’t heard them from the few reviews I read the D-Sonic amps supposedly punch way above their price and offer a trial period. Just a couple other potential options FWIW. Let us know whatever you find, and best of luck. |
Underwood HiFi was launching a 200Wpc GAN amp for $3000 under the LSA And don't throw this new one away yet just because it's very inexpensive. A US made and designed Class-D using GaN technology, for just $699!!!!!!!! https://www.classdaudio.com/mini-gan-5-balanced-power-amplifier.html https://premium-audio.com/ Cheers George |
I think Class D can be very good but class AAB done right is more natural overall.My Coda CSIB integrated amp Beats many excellent separates, in class D not one great Integrated , Merrill Audio very good but at $20- $30 k No thanks too many Class A-AB amps That are better .I have have heard others , which are very respectable ,but still a couple steps behind from my experiences. |
Yes not the best looking, but what’s inside is what counts, they "could" be as good as $5k ones for just $699 Otherwise if all that’s important is the look, then I call those "Glitz Queens" and they are usually the ones that parade their glitzy stuff on glitzy racks in between the speakers. Not caring they are totally stuffing up the imagine properties by doing that. But they don’t care as they are hypnotized by the shimmer of their equipment they are gazing at while trying to listen.. Cheers George |
A friend came over and lent me his KEF R3's. We were listening via my PS Audio DSSr DAC (Windom), BAT VK50-SE Preamp, and Jolida 3502p Tube Amplifier. Then he asked to swap in my ICEpower 1000ASP Class D Audio Amplifiers fed from the BAT Preamp and PS Audio DAC. Wow ! Why did I but the Jolida again ? Seriously, I'd been using the ICE Amps as Subwoofer Amps for the last eight months. I had no idea how much the Preamp would improve on the Class Dness of the Amplifiers. I used to own PS Audio M700, and this arrangement sounded just as good of not "better". No harshness whatsover. All the detail retrieval, Soundstage, Phanton Center, and the Treble/upper Midrange did not hurt the ears at all. Really did make me thin twice about the Jolida but I'm not getting rid of it. Tubes still outdo there Transistorized Counterparts Class A and Class A/B. Class D Amplifiers when fed a nice input stage can sound Phenomenal ! Those who have a hate on for Class D Switching Amplifiers, are just ignorant to be quite honest. |
@rajugsw said ”Those who have a hate on for Class D Switching Amplifiers, are just ignorant to be quite honest.” Or just experienced.. Sorry.. I had several class D amps starting with the Tripath, ICE and then Hypex .. Initially, they sound impressive, clean, clear and precise.. Then as time goes on and you realize they are not really musical, but fatiguing , bitter and analyzing.. Something about them is not organic and I found myself not listening to music as much anymore.. Maybe someday they will get Class D right.. but they work great in subwoofers. Sorry to be so harsh here.. but I tried a FEW times and did not have any musical success.. |
I believe MBLs electronics are Class D. Huge power and ability to drive anything at 4 ohms. They should be mentioned here. I personally have 5 Class Ds at the moment. Three of the five have tube input stages. Rogue Hydra, Canor AI 2.10 and AVM A5.2. I have a Marantz CR510 and an NAD M33. All five sound incredibly good for the price and are all very musical. Not fatiguing in the slightest. The tube input stage on the Rogue, Canor and AVM softens the digital sound and it is very musical. I have had them all driving Vivids and they sound fabulous. Stock tubes stink in the Rogue and Canor and do need to be changed. the M33 needs room correction on. With room correction, sounds like a completely different amp. But so does Onkyo. Without it can be cold and fatiguing. I have a customer with the C298 (same amp as in M33) and he has it paired with a VAC preamp and loves it. The one that is most shocking is the $500 Marantz network receiver. It sounds good. Very natural. No different than one of the class AB integrated language they sell yet is class D. No tubes yet great sound. Mar |
In my listening room, I started with a NAD M12 pre amp/NAD M22v2 amp combo and Tannoy DC8TI speakers. It took me a while to get the gain setting right, but once I did the sound was nice. The bass was great, mid range was good, but, depending on recording, it was sometimes too bright and not as musical as I would have liked. I replaced the M12 with a Herron pre amp, Herron phono pre, and Audio Mirror Tubdour SE DAC (very nice DAC!). That combination took the SQ to another level - everything sounded so much better. Not being satisfied, I sold the Herron and AM gear and bought a PS Audio BHK pre amp, DirectStream DAC, and Stellar phono pre. There was a clear SQ improvement - everything sounded so much better. Not being satisfied, I bought a PS Audio BHK 250 amp. Now I'm satisfied. I still have the M22v2 as my backup listening room amp, and plan to use it with a PS Audio Stellar Cell Gain DAC in another system. The M22v2 sounds really nice in my main system, but it is not a musical or smooth as the BHK 250. I could live with the M22 if I had too, I'm happy that I don't. |
ej sarmento at wyred 4 sound was an early mover in employing ice modules in his st series amp, with his nice discrete input stage driving the modules... his amps are as described below... laid back (even a little too smooth) with excellent bass except for the devialet units whose sound i love (lively, saturated, plenty of body yet transparent), the failing of the others i have heard is on proper decay of notes and ’air’ in sound staging there is something to the notion that many class d stages are a little too clean ... once again, sympathetic distortions can help our ears hear sounds we perceive as more natural, and in the proper space of a performance venue |
In the under 10K category, clearly the current winners are the AGD Audion monoblocks. What's coming this year in GaN engineering? Looking forward to the eventual release of the LSA Voyager (aka "Godot") amp, and to atmasphere's class D circlotron monoblocks. The other GaN amps currently out that nobody's mentioned are the Orchard Starkrimsons. |
In the under 10K category, clearly the current winners are the AGD Audion monoblocks. Clearly? How’s that? How many have these or have even heard them or compared them to all the others? I will give them credit for looking cool, what with the SS components plugged in and looking like a tube and all. |
"If that is the case then the designer didn't pay attention to the distortion signature. It can be quite low in a class D amp, but if the higher orders are not masked by the lower ordered harmonics it won't sound right." Bingo! Some class D on first impression can make you say wow but once you start to listen you began to realize that something is not quite right. I was talking to a friend on the east coast he has heard the Mola Mola integrated, top of the line Merrill and AGD amps and according to him he ranks the Mola Mola and AGD amps as not only the best of class D but some of the best amps he has heard period. I have not heard the Mola Mola amps but i do own the AGD Audion amps and i find them pretty special. |
A/AB IS THE WAY TO BE.If you are talking about solid state, the problem you are up against is linearity of the circuit. Class A is used to help improve linearity, but a very real problem faced by audio designers these days is the semiconductor industry would rather not make linear devices. So as a result unless one is very careful, feedback has to be implemented in the design to cause linearity. The problem here is twofold: first you have to be careful to not introduce oscillation by exceeding the phase margin of the amplifier circuit. The second problem is a lot trickier- you need to have about 35dB or more of feedback in order to prevent the feedback itself from adding distortion of its own (which tends to be highly audible as its mostly higher ordered harmonics). To that end you need a lot of something called Gain Bandwidth Product, which to feedback is a lot like gas to a car: When you run out of it there's no more feedback. Put another way, the feedback is gobbling up gain in the amp and this gain has to be sufficient to allow the feedback to do the same job at all frequencies. I'm really oversimplifying this issue but that is because its a very tricky engineering concept. For decades GBP has been sufficient in the bass region, which is why solid state has a good reputation in that regard. But its not been so good in the mids and highs- most amps made in the last 60 years have less and less feedback as frequency goes up, causing brightness and harshness as that is how the distortion is perceived. Incidentally, this is why distortion is usually measured at 100Hz. If distortion were measured also at 1KHz and 10KHz we'd have a far more accurate picture. Class D offers a rather elegant way around this by allowing you to impose so much feedback that the amp's phase margin is exceeded, and so it goes into oscillation. The oscillation is then used as the switching frequency, thus killing two birds with one stone. Now you can have in excess of 35dB of feedback so the feedback can clean up after itself. In effect a class D amp is more likely than not to have lower distortion than traditional solid state amps (class A or AB). Its also impervious to weird speaker loads causing it to oscillate because its already oscillating! Its very natural for a class D amp to make significant lower ordered harmonics due to how dead time and the encoding system make distortion. The result can be that those lower orders can mask any higher orders, resulting in an amplifier that sounds very much like a tube amp but with dramatically lower distortion and therefore more neutral. In addition its output impedance can be far lower than traditional A or AB amplifiers, allowing it to be a better voltage source. So put another way A or AB isn't always the way to be. |
D tech and it's hybrids are still in their infancy in terms of development with regards to 'high end' audio. Since the latter social group is basically small population-wise, the equipment for now will demand a stratospherically lofty price for those adopting it. There will be a time when a developed D amp will eat A & A/B's lunch, and make reservations for dinner.... ...'imho'.... |
My Benchmark AHB2 does a pretty good job but I don’t get drawn into lengthy listening sessions with it as much as I do with my SET amp. Benchmark seem to be one of the companies leading Class D technology in the US so check them out if you are considering Class D. This amp can either be used in stereo mode or you can use two in mono mode if more power is required |
Its also impervious to weird speaker loads causing it to oscillate because its already oscillating!However, the driven device forms part of the output filter and thus effects the frequency response. Tube amplifier frequency response also suffers driving widely variant loads. Depending on the interaction, the results can be chalk or cheese. In all things audio, the whole system and the room affect sound quality. |
I can mod your PS Audio 1200 amps to sound way better. The modules are basically stock (they only remove a coupling cap they don’t need because they already have Rel-Cap capacitors after the tube stage and they remove a resistor on the board that allows a higher impedance so the tube stage will drive it better). Benchmark does not make Class D amps. Class A/B with switching power supply. The Tsunami amps (I believe) are the $4750 amps from Legacy. They use stock IceEdge modules.....same as PS Audio 1200....PS Audio ($6000 the pair, needs upgraded tubes) adds tube front end. Again, I can modifiy the Legacy amps to sound way better. You can buy a dual mono IceEdge amp from Rouge Audio in Italy delivered to your door for $1600.....$3150 cheaper than the Legacy amp. This can be modded, as well. https://en.rougeaudiodesign.com/product-page/studio-n-10dm The output filter in a class D amp has very little effect on the frequency response. Please see Stereophile reviews where John Atkinson measures this. The output impedance of a lot of class D amps is seriously low and only rises at high frequencies to levels that are still below many class A or class A/B amps (certainly way below any tube amp). Please read and learn. The Vera amps are very, very similar to VTV here in US....the VTV amps using Purifi modules can be bought for as little as $999 delivered. Way, way cheaper than the Vera amps......again the VTV amps can be modified for way better performance. You more you search and read and learn......you will realize that you don’t need to spend a whole lot of money these days for great sound. As good as modified Purifi and IceEdge sound......my sense is that they are not as good as the $7500 AGD Audio Audion mono GaN amps........so, if you have that kind of coin and 85 watts is enough for you than this amp may be the current ticket to ride. However, If AGD made the amp into a dual mono stereo amp and put all the circuitry inside like everyone else (including no fake tube thang, no flight cases, no upgraded power cords) then they could sell it for $3500. So, whatever you buy today will be equaled or bettered for less down the road.....which is great news, really. |
D tech and it's hybrids are still in their infancy in terms of development with regards to 'high end' audio. Since the latter social group is basically small population-wise, the equipment for now will demand a stratospherically lofty price for those adopting it.This was true 20 years ago. But right now the tech is pretty mature if you look at it using the technology development sigmoid curve. We're not expecting our initial class D entry to be over $5000.00 yet its making similar power to class D amps that are $18,000.00 (Technics, for those keeping track). However, the driven device forms part of the output filter and thus effects the frequency response. Tube amplifier frequency response also suffers driving widely variant loads. Depending on the interaction, the results can be chalk or cheese.I think you might have a misconception here! Its true that the output filter is affected by the load. But it won't change the FR significantly because of two factors. First, the load affects the Q of the filter. What this means is with lower impedances the filter broadens a bit and is less effective- so you might see bit more of the residual (sine wave at the switching frequency). The second is that in a self oscillating amplifier there is so much feedback that phase shift and the audio passband FR are unaffected. Quite literally there's enough feedback to correct for issues that might arise if the filter is operating at a lower Q. In our prototypes and in our Beta production amps we're not able to measure a difference in frequency response between a 16 ohm load and a 2 ohm load. |
