Class D amps looking much improved
pearsall001
Posts: 5,068
Interesting reading on how far Class D is coming along. The newest items are GanFet & Purifi modules (Bruno's latest) I wonder how long before class A/AB get over shadowed...if ever.
Orchard Audio with their Starkrimson amp get incredible reviews along with companies implementing the Purifi modules.
Jeff Roland Model 125 really caught my eye. Rogue Audio also has a killer amp with it's DraGon.
The modules are only one piece of the puzzle. Analog stage still has to be implemented correctly along with the power supply. Things seem to be heating up for sure.
Should I be getting ready to pack up my 85lb amp????
Orchard Audio with their Starkrimson amp get incredible reviews along with companies implementing the Purifi modules.
Jeff Roland Model 125 really caught my eye. Rogue Audio also has a killer amp with it's DraGon.
The modules are only one piece of the puzzle. Analog stage still has to be implemented correctly along with the power supply. Things seem to be heating up for sure.
Should I be getting ready to pack up my 85lb amp????
"2 Channel & 11.2 HT "Two Channel:Magnepan LRSSchiit Audio Freya S - SS preConsonance Ref 50 - Tube preParasound HALO A21+ 2 channel ampBluesound NODE 2i streameriFi NEO iDSD DAC Oppo BDP-93KEF KC62 sub Home Theater:Full blown 11.2 set up.
Comments
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I totally agree, but... I have to go a bit pedantic here.
Sorry! I do think I know what you mean by "Analog stage still has to be implemented correctly along with the power supply" -- and I agree! 
I presume you mean the "analog front end", but bear in mind that the Class D (power) amp stage is also analog. 
Class D (pulse width modulation) is an analog amplification topology; the "D" was just the fourth identified class of power amplifiers after A, B, and C. The concept dates back to the 1920s. Practical PWM audio amps (albeit not particularly good ones) date back to Sir Clive Sinclair and the 1960s. Yeah, they're much better now.
I am not sure that there is any inherent advantage to Class D other than electrical efficiency -- it is (ahem it can be) far more electrically efficient than A or AB amplifiers. It can sound very fine indeed.
Class D really only makes sense when operated with a highly efficient (electrically) speaking P/S; i.e., a switch-mode power supply.
The downside of both Class D and SMPS is the spray of RFI hash generated by their operation. That said, the RF noise created by pretty much every other electronic gadget in our lives today probably drowns out the incremental noise from the amp and P/S -- but it's still at least a formal concern (from my perspective).
In all respects, though, I agree that Class D is the future of audio amplification, if for no other reason than its "green"-ness - and for better or for worse.
PS Modern Class D amplifiers do tend to have some digital processing associated with the output stage. Again, though, I think these are employed mostly to optimize the operation (specifically, the efficiency) of the amplifier and aren't necessary per se.
They'll pry my SE 2A3 amplifier from my cold, dead hands -- but, actually, I'll likely succumb to age before they come for our Class A and AB amps.
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source: https://www.worldradiohistory.com/Archive-All-Audio/Archive-Audio/60s/Audio-1963-06.pdf
source: http://www.vk6fh.com/vk6fh/sinclair x10.htm
Apparently the first "all in" consumer Class D amplifier product was commecialized by Infinity in 1976.
http://www.thevintageknob.org/infinity-DSP.html
Sony's Class D amp was neck-and-neck
http://www.thevintageknob.org/sony-TA-N88B.html
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They had a LONG way to come. I don't think they will ever rival good class A/AB amps. To me they both approach audio reproduction differently. I won't even listen to most class D amps. They are strident, in your face and hyper detailed. Not natural sounding. Even if they are a bit laid back they still sound artificial.
I'd give the new stuff a listen, but I bet I still wouldn't prefer it. I've never heard a natural sounding class D amp, they all sound artificial to me. Same goes for class G and H.
Just one class A guys opinion.
H9"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul! -
I run a class d boxem amp on my desktop and it sounds excellent.
I tried the bigger boxem on the grandes in the family room and it was no where close to any amplifier I have ever had in that room. It just didn't have... It- Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit. -
I haven't heard any yet that could.....yet. I do hear they keep improving it though. To me? They just sound artificial and not musical.
Tom~ In search of accurate reproduction of music. Real sound is my reference and while perfection may not be attainable? If I chase it, I might just catch excellence. ~ -
Strictly FWIW: I had a very cheap, low powered PWM amp using the old Tripath chip(s). I actually thought it sounded pretty good, albeit a bit dry. I wouldn't categorize it as strident. I even, finally, worked up the nerve to try it on the Duplexes -- and it wasn't embarrassing to listen to.
I've passed it along to our son, who uses it with a DAC and a pair of Cambridge SoundWorks Model Six loudspeakers (with the much-improved XOs published years ago in audioXpress) for his desktop hifi. AFAIK he's (still) pretty happy with it. -
Apollon NCx500ST …. State of the art for class D … gobs of power , almost zero distortion and affordable.
BkPS Audio S300 , WiiM Ultra , Yamaha wxc-50 , Salk SuperCharged Songtowers , Kimber Kable 4TC, Sony 42” - BEDROOM
B&K EX-442 ( it will go in my casket when I die ... ) , PS Audio 4.6 preamp ( old school , but it still jams on ... ) , Eversolo DMP-A6 , Boston Acoustic voyager 7’s - POOL
Parasound A21, Eversolo DMP-A8 , Kimber Kable 4vs , Ascend Acoustics ELX Ribbon Towers , Sony XBR-A8F 65” OLED - DEN , MAIN system
Onkyo TX-nr609 , Polk atrium 7 , Boston acoustic sound ware (4) , Boston acoustic sub , B&W center , Sharp 65” TV - PATIO -
Interesting discussion, in that , most guys here who have owned PS Audio S300 , M700 , M1200 class D amps have liked them …. Myself included.
Haven’t seen a negative review here regarding them …
I have owned plenty of class A/B’s and still have a S300 class D … My only “knock” against class D
is the lack of headroom … if you think you need 100w and buying a class D , get 200w+…. Zero headroom with class D , unlike class A/B or A .
BkPS Audio S300 , WiiM Ultra , Yamaha wxc-50 , Salk SuperCharged Songtowers , Kimber Kable 4TC, Sony 42” - BEDROOM
B&K EX-442 ( it will go in my casket when I die ... ) , PS Audio 4.6 preamp ( old school , but it still jams on ... ) , Eversolo DMP-A6 , Boston Acoustic voyager 7’s - POOL
Parasound A21, Eversolo DMP-A8 , Kimber Kable 4vs , Ascend Acoustics ELX Ribbon Towers , Sony XBR-A8F 65” OLED - DEN , MAIN system
Onkyo TX-nr609 , Polk atrium 7 , Boston acoustic sound ware (4) , Boston acoustic sub , B&W center , Sharp 65” TV - PATIO -
Gobs of power and no distortion means nothing about how it sounds. I prefer and it has been proven that simple circuits are better. I can't imagine the amount of futzing that has to be done to even get class D amps to sound better than earlier class D amps.
I realize we all prefer different sound, that's why there is so much gear out there. I am not saying I'm closed minded about the current class D. I won't spend my money on such and amp, but I would be open to hearing one. I think for HT it probably makes sense as it's a relatively good bang for the buck.
Clinical, dry, unnatural and artificial is what class D means to me. Which is 100% opposite of what I prefer. I get the idea of class D. It's relatively inexpensive, fits is a smaller and lighter chassis, uses an inexpensive power supply. It's a good bang for the watt type of amplification. Watts are the least measure I use for evaluation.
H9
"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul! -
I do use a (cheap!) Class D subwoofer (plate) amp. They're good for bass, I'd posit.
FWIW, I fully agree with @heiney9 about simplicity vs.... well... not simplicity. It's my biggest beef about Class D modules. There's a lot there to go wrong, and the modules are basically unserviceable when (not if) they do fail. The issue of "cradle to grave" green-ness of Class D is certainly debatable.
On the other hand, it doesn't get too much simpler than the amp I use -- but, in my case, the choice puts significant constraints on loudspeakers that bring out the best in the amp (and vice versa).
source: http://jelabsarch.blogspot.com/2012/06/je-labs-simple-452a3.html
(the driver circuit in mine is slightly different)
The class D amps do (in general*) seem to be somewhat more load dependent than most modern amplifiers. To that extent, they're a bit like zero global NFB DHT amplifiers (with relatively high output impedance) although the root cause is quite different in the case of Class D (PWM) amplifiers. In other words, they may tend to be pickier about loudspeaker pairing than a big beefy class AB ss amp with massive damping factor (and a linear P/S).
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* remember: All generalizations are false, including this one.
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Have you heard the PS Audio S300 ?
It’s not “end game” , but it sure sounds good…
BkGobs of power and no distortion means nothing about how it sounds. I prefer and it has been proven that simple circuits are better. I can't imagine the amount of futzing that has to be done to even get class D amps to sound better than earlier class D amps.
I realize we all prefer different sound, that's why there is so much gear out there. I am not saying I'm closed minded about the current class D. I won't spend my money on such and amp, but I would be open to hearing one. I think for HT it probably makes sense as it's a relatively good bang for the buck.
Clinical, dry, unnatural and artificial is what class D means to me. Which is 100% opposite of what I prefer. I get the idea of class D. It's relatively inexpensive, fits is a smaller and lighter chassis, uses an inexpensive power supply. It's a good bang for the watt type of amplification. Watts are the least measure I use for evaluation.
H9
PS Audio S300 , WiiM Ultra , Yamaha wxc-50 , Salk SuperCharged Songtowers , Kimber Kable 4TC, Sony 42” - BEDROOM
B&K EX-442 ( it will go in my casket when I die ... ) , PS Audio 4.6 preamp ( old school , but it still jams on ... ) , Eversolo DMP-A6 , Boston Acoustic voyager 7’s - POOL
Parasound A21, Eversolo DMP-A8 , Kimber Kable 4vs , Ascend Acoustics ELX Ribbon Towers , Sony XBR-A8F 65” OLED - DEN , MAIN system
Onkyo TX-nr609 , Polk atrium 7 , Boston acoustic sound ware (4) , Boston acoustic sub , B&W center , Sharp 65” TV - PATIO -
Efficient, lightweight and DETAIL out of my TI-based 3251 and 3255 amps. I'm looking forward to building another one (purifi or Ncore) when I run across a larger set of SDA's. I see why people "roll" tubes in their pre-amps. I popped in a different set (op-amps) than what the manufacturer implanted and it toned down the forward mids just enough where the sound signature and power matched my rebuilt classic Onkyo.Don't take experimental gene therapies from known eugenicists.
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Over here! Happily using a W4S Class D amplifier for 3 years now. Don't see myself ever going back to AB. The dynamics are incredible and it never runs out of steam. I love the beauty of a well designed AB like the stuff that Pass or Parasound put out, but I have come to prefer the compact, cool running nature of the D-amps.
Sound wise, in my opinion, the amplifier itself has one of the smallest effects on the overall signature of the sound from a system (*as long as it is providing ample power and not distorting in a bad way*). If it does that, and it reproduces everything you give it from the preamp, then its doing its job. The preamp, DAC, speakers, etc. have a much great effect on the overall sound (speakers being #1).
I'm sure there are many who would disagree, but that's my position. I've had more than a dozen fairly high end AB amps or integrated amps in my system(s) through the last 20 years including some John Curl Parasound monsters. When I first tried W4S's STI500, it was the first time I've experienced what seemed like unlimited dynamics (or at least within my listening levels). The STI had some weaknesses in its fairly simple preamp section which led me to sell it. After some patience, I picked up an ST500 sold my big LSA integrated, and went to using the ST500 straight from my DAC for a time, until more patience eventually led me to an STP-SE preamp to pair with it, which was my ultimate goal. I don't see myself ever getting rid of that pairing, unless I sell my whole 2-ch system at some point to downsize for some move to a smaller living space.
For rig details, see my profile. Nothing here anymore... -
As Trey mentioned, the Boxem Audio amplifiers are nice examples of the tech.
I have one of these which uses the newer Purifi Eigentakt modules: https://boxem-audio.eu/en/stereo-amplifiers/10-170-arthur-4215e2.html
If anyone is Class D curious I'd be happy to send it to you to try out for a few months to see if you like it, as long as you cover the shipping and return it in the same condition it arrived in. It's a good sounding amp with plenty of power, nothing digital sounding about it.
However, that being said, after becoming reacquainted with tube amplifiers recently, I'm not sure I can go back to Class D after hearing what a good tube amp can do. Shrug. -
I've owned many A/B amps in my life and the latest generation of Class D is working well for me. There's nothing "digital" sounding about it all (Class D is an analog topology). I've spent much of my life around live music and the latest versions sound realistic, rich, fast, dynamic and detailed. They are scary powerful. I'd like to hear the latest versions that employ GaN technology (another leap forward?). Good Class D is extremely neutral - you only get what is on the recording. I also get that the tube sound is very seductive, they just don't play well with my current circumstances.
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Why don't tubes play well with your current circumstances?
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Heat and breathing room in this solid cherry piece that my wife is very fond of.
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As a fellow lover of cherry furniture (or pretty much anything made of cherry wood), I appreciate this concern, but...Heat and breathing room in this solid cherry piece that my wife is very fond of.
You might be surprised about ventilation (i.e., how little clearance is actually needed) -- especially if the amp can be mounted so that air can get under it. Heat rises, as they say.
Also, a small boxer (muffin) type fan can be very quiet and move lots of air relative to the needs of a normally convection-cooled vacuum tube amplifier. The old trick of running those fans at half-voltage (e.g., a 220 VAC fan at 120 VAC, or a 12 VDC fan at 6 VDC) obviously cuts the airflow substantially, but renders them nearly silent.
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As Trey mentioned, the Boxem Audio amplifiers are nice examples of the tech.
I have one of these which uses the newer Purifi Eigentakt modules: https://boxem-audio.eu/en/stereo-amplifiers/10-170-arthur-4215e2.html
If anyone is Class D curious I'd be happy to send it to you to try out for a few months to see if you like it, as long as you cover the shipping and return it in the same condition it arrived in. It's a good sounding amp with plenty of power, nothing digital sounding about it.
However, that being said, after becoming reacquainted with tube amplifiers recently, I'm not sure I can go back to Class D after hearing what a good tube amp can do. Shrug.
Hey Drew,
If the offer still stands I'd like to see how the class D performs with my new Maggie 1.7i & definitely the sonic comparison with my HALO A21+ amp.
I tried to shoot you a PM but it said your account is private & wouldn't let me access.
Thanks,
Phil"2 Channel & 11.2 HT "Two Channel:Magnepan LRSSchiit Audio Freya S - SS preConsonance Ref 50 - Tube preParasound HALO A21+ 2 channel ampBluesound NODE 2i streameriFi NEO iDSD DAC Oppo BDP-93KEF KC62 sub Home Theater:Full blown 11.2 set up. -
The A21+ will , in all probability, have tons more current (60 amperes) than any class D …
Maggie’s love current , right ?
BkPS Audio S300 , WiiM Ultra , Yamaha wxc-50 , Salk SuperCharged Songtowers , Kimber Kable 4TC, Sony 42” - BEDROOM
B&K EX-442 ( it will go in my casket when I die ... ) , PS Audio 4.6 preamp ( old school , but it still jams on ... ) , Eversolo DMP-A6 , Boston Acoustic voyager 7’s - POOL
Parasound A21, Eversolo DMP-A8 , Kimber Kable 4vs , Ascend Acoustics ELX Ribbon Towers , Sony XBR-A8F 65” OLED - DEN , MAIN system
Onkyo TX-nr609 , Polk atrium 7 , Boston acoustic sound ware (4) , Boston acoustic sub , B&W center , Sharp 65” TV - PATIO -
pearsall001 wrote: »If the offer still stands I'd like to see how the class D performs with my new Maggie 1.7i & definitely the sonic comparison with my HALO A21+ amp.
You got it, will PM you! -
The A21+ will , in all probability, have tons more current (60 amperes) than any class D …
Maggie’s love current , right ?
Bk
Yes indeed Maggie's love plenty of horsepower along with high current. With that being said there are plenty of guys that say they have great results with not so powerful amps including low power tube amps. I've been following class D for quite some time & from all accounts they have no issues powering Maggie's.
We shall see, I'll be trying the Boxem amp in my system shortly. It's on its way for a comparison test. This will be a lot of fun!"2 Channel & 11.2 HT "Two Channel:Magnepan LRSSchiit Audio Freya S - SS preConsonance Ref 50 - Tube preParasound HALO A21+ 2 channel ampBluesound NODE 2i streameriFi NEO iDSD DAC Oppo BDP-93KEF KC62 sub Home Theater:Full blown 11.2 set up. -
pearsall001 wrote: »If the offer still stands I'd like to see how the class D performs with my new Maggie 1.7i & definitely the sonic comparison with my HALO A21+ amp.
You got it, will PM you!
I sent you my info via PM.
Thanks,
Phil"2 Channel & 11.2 HT "Two Channel:Magnepan LRSSchiit Audio Freya S - SS preConsonance Ref 50 - Tube preParasound HALO A21+ 2 channel ampBluesound NODE 2i streameriFi NEO iDSD DAC Oppo BDP-93KEF KC62 sub Home Theater:Full blown 11.2 set up. -
This should be interesting!
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"2 Channel & 11.2 HT "Two Channel:Magnepan LRSSchiit Audio Freya S - SS preConsonance Ref 50 - Tube preParasound HALO A21+ 2 channel ampBluesound NODE 2i streameriFi NEO iDSD DAC Oppo BDP-93KEF KC62 sub Home Theater:Full blown 11.2 set up.
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Very generous of you, @Clipdat . Did your Luxman preamp arrive?
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Yes it did, I'll throw up a quick photo I took of it in the other thread. Haven't had a chance to hook it up yet as it will require equipment rearranging in the rack.
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One of the reasons for the recent improvement in class D amplifiers is the use of "post filter feedback" (PFFB) to reduce high frequency harmonic distortion and flatten out the frequency response.
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I have been VERY tempted by a Nad M32 or M33. This thread isn't helping!Living Room 2.2: Usher BE-718 "tiny dancers"; Dual DIY Dayton audio RSS210HF-4 Subs with Dayton SPA-250 amps; Arcam SA30; Musical Fidelity A308; Sony UBP-x1000es
Game Room 5.1.4: Denon AVR-X4200w; Sony UBP-x700; Definitive Technology Power Monitor 900 mains, CLR-3000 center, StudioMonitor 350 surrounds, ProMonitor 800 atmos x4; Sub - Monoprice Monolith 15in THX Ultra
Bedroom 2.1 Harmon Kardon HK3490; Bluesounds Node N130; Polk RT25i; ACI Titan Subwoofer -
The Fosi Audio V3 mono amplifier is an interesting design.
