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.
But any speaker manufacturer worth his salt will tell you that doubling
up on low order high power filters at or around the same area has it own
set of problems with ringing ect.
While this is true, this does not translate to the filters used in a class D amp, which is operating well outside of the audio band. The filter on a class D amp is blocking the switching noise of the amp and nothing more; it does not pay to have that filter go any lower than need be on order to be effective.
If the amplifier is switching fast enough, the internal inductance of the speaker itself is often enough to block the switching noise.
You are right @stfoth, some 10 years ago, most class D amplifiers that I listen to sounded either hi-fiish -- like a Technics stereo of the early 1980s, or darkling, or hazy, or even outright screetchy... Yet, even some 10 years ago, some class D amps were already making real music... I fell totally in love and adopted one of the few class D amps which made real music without compromises: The Rowland M312 stereo.
Today the class D field is very different. While you might still find the occasional screetch owl out there, most class D amps seem to be making real music, and more than a few are exceptional music makers. In general, you cannot go wrong with amps based on NCore NC1200 or Pascal M-Pro2 modules.
George, Bel Canto M600 is a relatively entry level monoblock amp. Using the scaled down NC500 NCore module, They were conceived to fulfill price point of a price sensitive segment of the market. At $5K/pair, They are not an attempt to scale the summit of absolute performance levels of amps based on the full NC1200 modules or Pascal M-Pro2 and X-Pro2 modules.
Hi Lalitk, the Rowland M725 monos are based on a class A/B topology. You might have meant the M825 stereo instead, which like M925, sports NC1200 modules.
Nord is making nc500 based amps with a user selectable and user changeable input buffer to "tune" the sound to one's personal preference. It has been getting great reviews and is offered at extremely low prices given the performance. It can be made to sound any way the user prefers....
"The only current crop of D’s I’ve heard that have semi impressed, were the new Belcanto Ref 600M Monoblocks, yes they use the the newest "best" N-force NC500 modules that aren’t available to anyone but to Belcanto and other manufacturers"
You should get your facts right. It's not N-Force, it's NCore NC-500 Hypex Module. And there is no modification to NC-500 module itself. Inside REF600 there are three circuit boards: a Hypex NC500 amplifier, a Hypex SMPS1200 power supply, and Bel Canto's input conditioning board with their Impedance Optimized Input Stage, for balanced, high common-mode rejection and to provide a low output impedance to the input of the amplifier board. The active element on the board is an LME49720 Dual High-Performance Audio op-amp in what appears to be a low-pass filter configuration.
"The only current crop of D's you heard is REF600" - Are you always been this short sighted that after listening to one class D amp, you see fit to under appreciate or rather condemn the recent innovations and forward progress in Class D camp.
I wonder how many Class A/B amps you auditioned before settling with the one you currently own? And is that the 'best" Class A/B amp made in the world?
If you seek the "best" in Class D currently available, I double dare you to audition Jeff Rowland's 925/725, Mola Mola's Kaluga and Merrill Audio's Veritas before you return to another Class D thread.
As one of the reviewer pointed out, "the REF600M didn't sound identical to some other amps was neither surprising nor a criticism of any of them. Of three recent amps of my experience, the REF600M was the warmest, the NAD Masters Series M22 the most detailed, and the Theta Dreadnaught D somewhere in between. Why should various amps based on circuit boards of the same technology (NCore) and made by the same company (Hypex) sound different? I don't know, but the amplifier boards aside, I could see physical differences inside these three amps. The big Theta uses a big linear power supply or two, while the more compact Bel Canto and NAD use a Hypex SMPS. Theta and NAD use the input circuit on the NCore amp board, while Bel Canto supplements it with a proprietary circuit"
I just got some digital amplifier company inline maraschino class d amps to replace my Odyssey kismet class ab monos and I'm amazed how good they sound. I used to have an emerald physics ep100.2se class d stereo amp and the inline maraschino blow that away and is on the same level as the kismets
And stop with the ten-year old stories. Get in the now.
The only current crop of D’s I’ve heard that have semi impressed, were the new Belcanto Ref 600M Monoblocks, yes they use the the newest "best" N-force NC500 modules that aren’t available to anyone but to Belcanto and other manufacturers.
But Belcanto modifies them from what I’ve we were told by the importer/demonstrator, that was to either cascade/parallel or series a couple of the low order switching noise output filters to give a sharper filtering effect of the switching noise.
But any speaker manufacturer worth his salt will tell you that doubling up on low order high power filters at or around the same area has it own set of problems with ringing ect.
Stop listening with your eyes (reading specs) and start listening with your ears. That is the only proof needed. And stop with the ten-year old stories. Get in the now.
stfoth it’s been awhile since I knowingly gave any class D amp a good listen, maybe a decade. so, some folks absolutely love these things. others can hear the flaws. my impression from a decade or so ago was that I hated them (at least the few I heard), but really couldn’t put a finger on why--lots or power, ridiculous detail, etc. just something missing, and, inexplicably, my ears felt funny afterwards--almost like a ringing that shouldn’t have been triggered by the volume or duration. difficult to explain.
+1 stfoth, others hear it too, and if they can’t good for them. This is why there are for and against post, from both sides of the camp, so potential purchasers can make up their own minds, and be happy with it or disappointed. These forums are not a marketing exercises to create a push to sell more Class-D. As the opening post says " Please share your experiences with class D amps!"
The simple fact is there is no perfect amp or class of amp. All classes have there pluses and minuses. It is up to the end user to prioritize what is most important to him personally, and to make his personal choice. There is no legitimate reason for others to criticize one’s choice. It’s usually those who are insecure and need outside validation for their own personal choices who criticize what others have found to be optimal for themselves.
I have owned and listened to tubes and ss. Ncore does it for me. I don’t need some audio "expert" to tell me what to like. Nothing as obnoxious and unwanted as someone trying to save others from themselves.
The best way to kill a troll is to stop feeding him. Let's quit replying to him and perhaps he will get the hint.
Isn't it funny how when some tube amp, or SS class A or A/B amp, falls flat on its unmusical face, everyone shrugs it off as a isolated flop in an otherwise most vaunted class of operation....
Yet, when such a flop is on a class D amp, that is taken as proof positive that class D is immature, or even inherently inferior.
He has already shown he has no manners or respect by his continued presence here, where he has nothing positive to add to the thread, a thread that clearly states it’s for those satisfied with class d, not those that get off by sowing dissent and trolling.
Sorry, but he has nothing but tired, yesterday’s news to share. Class d has moved along, as many people here already know. No one is protecting their investments, they are just trying to enjoy the sunshine without some thread crapper peeing on their parade. Word gets out? Wow, wake up Rip!
I wonder how those that are into tubes would react if you wandered into their thread uninvited and started crapping all over it preaching about the issues with tubes....
rather than attacking the dissenter in your little circle, you might pay attention to what he is saying
+1 Randy-11 It’s because they can see the forest through the trees, understandable as they’re protecting their investments, as it will make theirs very hard to sell once it becomes available and the word gets out.
BTW can find anything on the Mytek, claim of new developments that address the problems of Class-D. Being a small company I doubt also that they have access to the new higher switching frequency components from GaN. I think for now maybe Technics has a strangle hold on supplies.
Perhaps I can buy some IC's that are six feet long and put the Tuner several feet from the Dayton to see if that solves the problem.
Not sure what is causing the issue. My cassette deck plays just fine with it. Noted the instruction manual for some of these Class D integrated amps mentions that Tuners and Cassette players may have shielding problems from the noise coming out of the amp itself. May be a design issue with the cheaper Class D amps.
Hi will62, I have experienced some RF leaks out of older class D amps based on ICEpower 1000ASP modules. I am talking about amps in production until 2010 or so. Typically, an FM tuner picked up hash unless it was some two feet away from the amp.
By contrast, well designed amps based on Hypex NCore technology like Merrill Veritas or my own Rowland M925 do not leak at all... Not that you would want to do it, but if you had no better logical placement, you can sit an FM tuner on top on an NCORE amp with zero side-effects... Yes, I speak by experience.
Please note that I have no idea about RF leaks from the current generation of ICEpower amplifiers.
So I know people are used to me laughing at most 1980’s attitudes about Class D. However, the reality is that some Class D can emit a lot of RF noise, I think Putzeys writes somewhere that it can actually cause cross-interference if two Class D amps are too close together.
Will, it’s worth investigating HOW that interference is happening. It could be via the case, power or interconnects. If in the interconnects, or power cord, using snap-on ferrite donuts can tame it.
Something like this could be useful, but check the inner diameter:
I have compared amps side by side with older Hypex Ucd and Hypex NC500 and I could not discern any major audible differences. As others have pointed out, It's all in the design implementation and most importantly the power supply.
To 'kuribo' point, I would stay away from any Class D amps that uses off the shelf parts like those DIY kits (NC400) amps being sold from $500 and up. IMO, they do not represent the very best Class D has to offer. They may be the best bang for the buck but certainly not what I call tip of the iceberg.
I know a close friend of mine recently switched from a NC400 mono amps to Mola Mola's and he swear by Kaluga's excellent sound.
You can get around it by using a properly designed and implemented class d amp like those from Hypex. Good class d is very hard to do. Many poor quality products out there that do no favors to class d....
Have a Dayton T120 amp. Class D. Replaced it with a Yamaha Receiver for now because I needed something that had more inputs and could also play nice with my Tuner. Have read and can confirm that at least in the case of the Dayton amp, it creates so much noise with a tuner that it is useless for trying to use a tuner with it.
Has anyone else had this problem? If so how did you get around it?
Just as an aside, and not meant to cause a flame up, being so hard and fast with how class D has to progress in certain areas in order to be considered decent doesn’t make much sense. The only class D set up that I’ve listened to for more than 30 minutes is the Audio Alchemy brand and it uses the older Hypex UcD version that Bruno says is inferior to what his latest NCore offerings.
I’ve heard both types and I’ll take the Audio Alchemy approach to his Mola-Mola approach, hands down. I’ve heard the Mola-Mola a few times, in different set ups, and it was always too polite, laid back, and seemed to lack dynamics. I know it’s all in the implementation and it seems that Peter Madnick knows his way around the Hypex unit, as well as lots of other ones since he’s been involved (without public credit) in the design and implementation of lots of other class D projects for other makes.
If I had the funds, I’d sell my Marantz Reference integrated and take a chance on the Audio Alchemy: it impressed me that much.
At the extremes of 'performance', there's 'differences' in the nuance between the various amp classifications. No doubt, no kidding, and no big surprises there. When tubes met transistors, I remember the 'dust up' over that...and then, tape vs. vinyl with cassettes....and then the CD format began the digital 'evolution'. We're still 'A/B'ing THAT...
Will there Ever be a resolution over Anything? NO. *L*
We all approach things with different expectations over (as far as my experience goes) Any Damn Thing you can bother to name to me. *L*
Our audio, cars, homes, spouses, children, friends, employment, the *sshole next door or the nation/state on the other side of the f'n planet. It doesn't surprise me that the aliens are staying away from us for that reason, either.
We're so damn fractious that we'll argue over the color of daylight. I'm happy that we can co-operate at all...
I apologize...I don't mean to launch into a rant 'n rave, but Sometimes... the obvious seems to escape us. You will like what you like. You will disdane what you don't. I may think you are out of your mind; you will feel the same towards me. That's fair. As long as you like what you've chosen to surround yourself with, I'm good with that and will wish you well. If I choose to squat in garbage, well...if I'm smiling, that ought to do it for me...;)
There's more important things at the end of the day...right?
I like D. It's evolving. We are, too. 'Twas always thus, and will always be. Just relax, and watch the floor show. Try to be entertained...*G*
When I'm watchin' my tv and a man comes on and tell me How white my shirts can be But, he can't be a man 'cause he doesn't smoke The same cigarettes as me
That is interesting, George has been hawking this for a while.
However, since I cannot hear any problems with good class D, I won't be put out if I stick with "slow" transistors. They work just fine for me.
One really interesting thing about the Technics however is the heavy DSP processing they rely on to flatten the electrical amplitude and phase response. I'm tempted to do this with a miniDSP to see if I hear any benefits.
Not any time soon though, this apartment doesn't lend itself well and I'm all out of funding. :)
Just by reading your posts, I am convinced that you are stuck in Class A/B la la land. Since you're struck there that can only mean one thing: not being firmly in the present.
Through either anxiously living in an anticipated future or stuck in the habitual past, we cut ourselves off from the inspiration and creativity that exists when we are fully present.
The following five steps may help you clear away the mental cobwebs, swiftly returning you back to the creative flow where you belong.
1. Hit the Shower 2. Seek out Sweat Sessions 3. Change the Channel 4. Change the Environment 5. Still stuck, seek professional help.
Class D is here and contending head and shoulders with Class A/B.
Well said, as I've also stated, even I will ditch my boat anchors when the technology allows that dreaded switching frequency (Class-D's Achilles heel) to be 2-3 times higher than what it is. Then it will be an amp to contend with.
....and I'm happy to see that this thread is having some relatively 'healthy' give 'n take. *G* (Knuckle bump to Eric)
D will become Dominant; it's just a matter of taming the beast to become 'tolerable' to those of us with 'sensitive ears'...
*S* Yes, that's a tad snide, but y'all have to be a little patient for the designers and manufacturers to 'get it down'. ;)
I won't be surprised if some wag comes out with a D amp that has a option that would duplicate the 'sound' of an A, an A/B, or whatever... Perhaps a function labeled 'Variable'. *L* Twiddle 'till you're seriously happy or seriously disgusted....
Some people can't get over the fact that not everyone sees, or hears, things the way they do. While most people are happy to let others enjoy whatever pleases them, some can't help but pee on their parade. It must be some sort of perverse character flaw.
BTW, I've had a number of golden eared audiophiles listen to my system. The issue of Class D never comes up until the end. No one ever says "OH, wow, I can hear the Class D problems!"
We talk music, headphones, speakers, and room acoustics. On the way out some one will ask, "Oh by the way, where are your amps??"
It’s a digital amp, not a class d amp. From the Absolute Sound article on the Technics SE-R1:
"Digital Amplifiers As with Class D amplifiers, digital amplifiers use a switching output stage; however, they accept digital rather than analog input signals. These “digital” amplifiers take in the pulse-code modulation (PCM) signal from a music server or other source and convert those audio data to a pulse-width modulated signal. This PWM signal then drives the output transistors, just as in a Class D amplifier. The difference between a Class D amplifier and a digital amplifier is that the digital amplifier accepts digital data rather than an analog signal."
Perhaps it’s more like a power dac....
Regardless, there is no doubt it sounds great, just like the Hypex ncore....People can whine all they want about switching speeds, blah blah blah...the ears don’t care...luddites need not apply...
George is correct in categorizing the Technics SE-R1 as a class D amplifier. It uses a pulse-width modulated switching output stage, and it is therefore a class D amplifier by definition. Various architectural differences that it has with respect to most other class D amplifiers, including the ability to accept digital inputs from a mating Technics preamp and keep the signal in the digital domain until it is converted to the PWM signal that controls the output stage, do not change that fact. Statements such as the following, which appeared in this TAS review, are misleading and incorrect in drawing a distinction between class D and digital amplifiers:
Indeed, this is not a traditional Class A, Class AB, or even Class D amplifier. Rather, it is a rare breed known as a “digital” amplifier....
As with Class D amplifiers, digital amplifiers use a switching output stage; however, they accept digital rather than analog input signals. These “digital” amplifiers take in the pulse-code modulation (PCM) signal from a music server or other source and convert those audio data to a pulse-width modulated signal. This PWM signal then drives the output transistors, just as in a Class D amplifier. The difference between a Class D amplifier and a digital amplifier is that the digital amplifier accepts digital data rather than an analog signal.
What would be correct would be to say that a "digital amplifier" in this context is a form of a class D amplifier. And as such, like any other class D amplifier its design must address the issue of output stage switching speed. And the sonic consequences, if any, of the low pass filter at the output of the amp for which the required bandwidth is a function of that switching speed.
No I didn’t say that Techinics"finally fixes the Class-D problems. I said: " they (Technics) seem to address to a certain extent the problems that they all have still"
Really? Just because it uses a linear rather than a crap SMP power supply, doesn't mean it's not Class-D
From Stereophile: " Although the SE-R1’s huge twin output meters and beautiful anodized-aluminum finish were visually distracting, the marketing of a Class-D amplifier as a separate high-end component was important. This amplifier delivered some of the best reproduced sound at CES 2017. I persuaded Bill Voss to rip the contents of my copy of Rutter’s Requiem to his media server’s solid-state drive. The broad and deep soundstage, imaging, upper midrange detail, and bass extension were thrilling during the system’s rendition of "Lord, make me an instrument of thy peace" and "Pie Jesu." I appreciated the work done by the Technics staff to prepare their exhibit suite with recessed sound-absorbing panels. I left wanting to hear more."
From Audioholics: " On the amplifier side, the SU-C700 and SE-R1 are utilizing advanced Class D topologies, featuring a couple new acronyms, JENO and LAPC. JENO (Jitter elimination and noise shaping optimization) provides clock regeneration for low jitter switching in the amplifier stage, sample rate converter, as well as a pulse width modulator that feeds the output stage. LAPC (Load Adaptive Phase Calibration) on the other hand is designed to maintain frequency and phase response regardless of loudspeaker impedance, which is a weakness in some Class D implementations. Finally, the output stage utilizes gallium arsenide FETs (field effect transistors) with a claimed switching speed of 1.5MHz."
From Audio Aficionado: " .I read a blip in The Absolute Sound that the Technics SE-R1 power amp ($18,000.00) is Class D. It uses a linear power supply rather than a switch mode power supply to produce 100 watts per channel. That’s a lot of money for a 100 w/p/c Class D amp. Along with the Technics SE-R1 Class D amplifier they also introduced the SU-R1 Network Audio Control Player preamp ($9000.00) and new SB-R1 Reference Speaker ($27,000.00). Technics calls this system the R1 Reference System."
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