Class D is just Dandy!


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.

Please share your experiences with class D amps!
erik_squires

All, doubtless George enjoys throwing red herrings that are well past their prime... And the whole argument of... If a luminary like ML could not do class D right, it must mean that class D is not ready for prime time is, well.... A logical fallacy called  a flawed induction step.


On the other hand, this being an open forum hosted in an open Country, asking friend George to decamp and settle on a more traditionalist audio watering whole is not a very nice thing to do to an old friend.


His amused needling of us is actually refreshing... Makes us remember that things are ever evolving, and that what we deem fabulous today, will before long be deemed obsolete. And who knows.. May be those superfast transistors he is always talking about will before long let class D amps achieve this vaunted realm of 0.003% distortion.


Oh... I must be daft. NCore NC1200 based amps are already capable of 0.003% distortion plus or minus some smidjin.... using standard 500Khz switching frequencies... Oh well, Need to find something else that class D can'd do.... We sure wouldn't want to use our ears and discover amazing music on class D to our chagrin, wouldn't we?!


G.

   

@sfseay -- did your Auralic Meraks come with power cables? If so, are  you using them or do you find they sound better with something else?
@mdeblanc - I used the power cables that came with the amps.  I don't put much stock in swapping power cables.  It is never been proven they impact sound and people claim they hear a difference but in blind tests they can't.  Their ears fail them when their eyes can't see.  

I have two PS audio signature power cables that came with a PS Audio PCA-2 preamp I bought not long ago.  I use one for the PS Audio HCPS and one for my Sony HAP-Z1.  I don't notice any difference in the sound.  I will ebay the power cables and use the money to buy CDs or High Res files.

i just bought a Luxman integrated amp to save space, and will probably sell the Meraks and the PS Audio preamp and HCPS to pay for the Luxman.

@sfseay

Not sure about how sighted tests of power cables would even work.... May be some rare sighted people are able to hear through their eyes instead of their ears?!


Oddly enough, I experience no difficulty discerning differences amongst power cords, exotics and inexpensive ones alike. On the other hand, what would I know.... I have been as blind as a bat in a sealed barrell of tar for the last 33 years. All my audio tests have been totally blind ones since 1984.


I must be really unfortunate, being bount to  listen to music only through my ears *Grins!*


G.

 

Like I said once before, to the ones that have blinkers on, they will be the first to change to the higher switching frequencies when they become available, that's almost a given. 
As for now maybe just trying to protect their investments, with ignoring that the higher switching frequencies will give them what many hear is a problem with Class-D, which effects the upper mid/highs.

Cheers George  

Hi George, it is quite possible that an increase of switching frequencies by by a factor of 2, 5 or possibly 10 might very well enhance the sound of well designed class D amps.... Or at least, such higher frequencies might be a contributing factor.


I have not heard the new Panasonic that use these new transistors, so I do not know how they would compare to the current crop of the better class D amps.... But sure am curious.


And when reproduced music becomes even more enchanting than what I experience now from my Rowland M925 monos, I'll be the first one to celebrate the event.


Have you heard these new Panasonic amps yet? If you have, please let us know your first hand impressions.


Saluti, G.



I have not heard the new Technics that use these new transistors, so I do not know how they would compare to the current crop of the better class D amps.... But sure am curious.

Have you heard these new Technics SE-R1 amps yet? If you have, please let us know your first hand impressions.

Saluti, G.

No I haven’t yet as the Technics SE-R1 is unobtainium here in Australia, and you need to order them and have deep pockets in counties that do retail them.

But from the number of Class-D’s I had here listened to and measured, they (Technics) seem to address to a certain extent the problems that they all have still, which is the filtering that has to get of the switching frequency noise, without it effecting the audio band in any way, and the only way to do this is to raise the switching frequency by at least triple, Technics have done double with the SE-R1 so were on the way.

But these are typical of reviews (below) of the sound they give out from those that have heard it, and there are more from others on the web.

" Listening to tracks that we’ve heard 100s of times — and on excellent systems at that — is now a revelation of once hidden nuance and detail. Not only are we hearing things we’d never heard before, we’re hearing it in a way we’ve never heard it before. A music system that sounds like a live performance is a tough goal to attain, but Technics’ flagship nails it."

Cheers George
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."

Cheers George
So George would like you to believe all Class D amps have issues, but this one future amp finally fixes "The class D problem."  and reviews say so.

Hahahah.

BTW, technically this may actually be a Digital Class D amp, given the A/D conversion and processing.

Best,

E
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"

Cheers George
That's enough class d nonsense for me,I'm saleing all of mine and going to buy more first watts.

Best,

Kenny.
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.

Regards,
-- Al

I see our thread crapper is still here...


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...
The non-existent problems? Oh, but wait, they only address the non-existant problems but never actually solve them. Damn. And all that money.

Maybe people should just stick with inexpensive Class D amps available already which fixes it all.

George has nothing but shade. WEEPS.
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??"
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.
I'm happy everyone's hears what they hear.  I don't believe anyone's hearing opinion when it comes to "audiophile gear".  I believe only mine.
....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....

Ah, the Future....Live It, or Live With It.... ;)


asvjerry
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.

Cheers George


@georgehifi 

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. 


@asvjerry

I cannot hear the difference between my class D amps and Parasound A23s. Zero. None. Therefore, small, lower stand-by power wins.

But there are interesting hybrids. NuForce is basically class D voltage rails + Class A linear amp. Yamaha’s EEEngine technology is similar.

Both could be considered derivative of the NAD/Carver voltage tracking power supplies.

Best,

E
Hi Tim,

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. :)

Best,

E

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

- The Rolling Stones, 1965
*L*  Yeah, that cuts to the chase, doesn't it...;)

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*
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.

All the best,
Nonoise
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?  
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....

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. 
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:

http://amzn.to/2sGdR49

Worth trying on the tuner's AC cord as well.

Best,

E

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.

 

G.


Guido


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.
rather than attacking the dissenter in your little circle, you might pay attention to what he is saying

now, I am interested in hearing the new class D from Mytek, even tho I seriously doubt they use Ga
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.

Cheers George
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....

Where are the moderators when you need them?

Nothing shows respect for the people you are interacting with less than straw man arguments and innuendos.

I’m really unhappy to see it here.

Best,

E
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.

Go away troll...

I am with you Kuribo!


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.


Saluti, G.





Post removed 
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.