The Truth about Modern Class D


All my amps right now are Class D. ICEpower in the living room, and NAD D 3020 in the bedroom.

I’ve had several audiophiles come to my home and not one has ever said "Oh, that sounds like Class D."

Having said this, if I could afford them AND had the room, I’d be tempted to switch for a pair of Ayre monoblocks or Conrad Johnson Premiere 12s and very little else.

I’m not religious about Class D. They sound great for me, low power, easy to hide, but if a lot of cash and the need to upgrade ever hits me, I could be persuaded.

The point: Good modern Class D amps just sound like really good amplifiers, with the usual speaker/source matching issues.

You don’t have to go that route, but it’s time we shrugged off the myths and descriptions of Class D that come right out of the 1980’s.
erik_squires
You and everyone knows exactly what that is, you’re just being a giant PEST! as usual Eric, you were told, now ____ ___ and bag Nelson Pass or something, that’s what your good at.
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Whatever you say Ralph as I said, your the "Strawman", you know you were compassing the office type "dinky as I said"150w GaN Orchard type GaN amp to the Technics SE-R1, your not fooling anyone.
Ralph get it right your the false one with strawman mentality, you can’t have it both ways, the two 150w amps (Technics SE-R1 v Orchard Bosco) are very different, and will not be the same, and I’m sure your answers are "protection blurb" for what you have coming. Stick to tubes that's where your cred is.
If you look back at this you will see that I am not claiming that they are the same. I was simply saying that a module the size of a pack of cigarettes is that way on account of it has to be so to ameliorate noise issues.


And again, your argument quoted above is yet another Strawman. A Strawman is an argument different from the one which which your opponent in debate has presented; by then knocking down a different argument you can still think of yourself as correct. It works only if  others don't notice the slight of hand. You've been correct in your arguing but incorrect in addressing my points. 
You did, because you called me out on saying this, to which I was making reference (dinky) to the Orchard Audio Bosco 150w type ones
The ones around now using GaN’s are either dinky little office type class-D’s or expensive ones that haven’t utilized the technology as far as Technics did.

To which you responded
This statement is false. The Technics amplifier is only 150 watts, which is similar power as many of its GanFET competition.

Ralph get it right your the false one with strawman mentality, you can’t have it both ways, the two 150w amps (Technics SE-R1 v Orchard Bosco) are very different, and will not be the same, and I’m sure your answers are "protection blurb" for what you have coming. Stick to tubes that's where your cred is.


You are saying this 0.9kg 150w Gan amp
https://orchardaudio.com/bosc

Will not be shamed by this Technics SE-R1 54kg 150w GaN amp
Nope. Didn't say that. I merely pointed out that class D circuits have to be compact. The above is a Strawman logical fallacy; thus inherently false.
Here’s my worthless 2 cent contribution which I may have posted about previously. When Paul McGowen of PS Audio set out to make a world class amplifier (at a "reasonable" price) he built custom input stages coupled to I believe Hypex modules at the time (not the very top model since he was using his own input stage anyway) He was quite happy with his design and brought it to the late Arnie Nudell’s (founder of Infinity) sound room to play on his prototype new smaller IRS speakers. When compared to Arnie’s custom tube amp he had commissioned, Paul’s designs continued to fall flat compared to Arnie’s reference, try after try. I believe he finally told Paul if he wanted to build a world class amplifier he’d have to scrap the project and hire Bascomb King (of Constellation, Marantz, Infinity as well as a respected reviewer/measurement writer) to design the amp from scratch. The design he came up with was MOSFET class AB and Bascome’s design beat Arnie’s reference, (which he promptly sold to make room for a BHK.)

I think it’s amazing that Paul kept his public informed along each advance and setback over the years. The time I waited for the BHK line to be released was worth it,

The R&D on Class D may have helped later with their lower priced amps, and from what I’ve read they sound really good, but there is a reason the MOSFET amps exist as their flagships.

Incidentally, Paul was very anti tube and PS had never released a tube product. Bascom convinced him to at least listen to a tube input stage. It was agreed and even planned to release the BHK’s with two input options, one tube and one solid state, built on tube socket for easy switching. But once they auditioned the two designs, it wasn’t even worth releasing the solid state version, and PS Audio had its first tube product and achieved its goal to be a top contender in amps (especially the mono blocks, which were conceived as a convenience option with only 50 watts more, but who’s balanced design once rolled off the assembly line and heard for the very first time proved to reveal another level of sonics above the stereo version. Of the few people that have heard the BHK (I imagine the mono) versus the much more expensive and top reviewed Constellation, they preferred the BHK.


Class d amplification development is similar to digital format source, began with 16/44, then 24/96 to 32-bit/768kHz, in future will be....
This thread is now a closed time loop of condescension and claims without evidence or logic.

Lets have it closed and stand as a monument to the character of the contributors.

atmasphere7,984 posts02-26-2020 3:39am
The ones around now using GaN’s are either dinky little office type class-D’s or expensive ones that haven’t utilized the technology as far as Technics did.
This statement is false. The Technics amplifier is only 150 watts, which is similar power as many of its GanFET competition.


asvjerry Well, until someone somewhere puts these two competing amps between a pair of quality speakers with ditto level cables....and source up to par to the task....

It remains conjecture, and opinion.

Really?? your cred if any just took a big dive too, if you think for one micro second these two 150w Class-D GaN amps could possibly sound as good as each other.

https://orchardaudio.com/bosc 0.9kg

https://i.pinimg.com/originals/e1/ce/1a/e1ce1a9c552aa57530ad2804c9067800.jpg 54kg
"....it plays jingle bells."  Damn....how tragic.
Hope your voice survived....

Well, until someone somewhere puts these two competing amps between a pair of quality speakers with ditto level cables....and source up to par to the task....

It remains conjecture, and opinion.  The 'referee' has already rang the bell once, with a warning to the combatants....

It's still summer in AU...right?
Maybe something you don't understand is that the size of a class D circuit board says little about its power


Ralph you've been in the sun too long mate.
I understand fully Ralph what you are saying to me, two GaN amps below the same 8ohm wattage.

You are saying this 0.9kg 150w Gan amp
https://orchardaudio.com/bosc

Will not be shamed by this Technics SE-R1 54kg 150w GaN amp
https://i.pinimg.com/originals/e1/ce/1a/e1ce1a9c552aa57530ad2804c9067800.jpg

Sorry Ralph pull the other one it plays jingle bells🤦‍♂️




I’m talking about dinky ones the size of cigarette packet, some that can do 120w
Maybe something you don't understand is that the size of a class D circuit board says little about its power. They have to be small in order to keep radiated noise down. So traces are short (less inductance), there are usually at least 4 layers in the board and so on. So a board that is the size of a pack of cigarettes is that way even if it can make more power. Most circuit boards (modules) employ ICs to do most of the class D functions- comparator, drivers for the outputs, high side switches and so on. This helps them be more compact and so less noisy. Our prototype boards make 100 watts and despite being relatively discreet (no dedicated chips) its smaller than a pack of cigarettes too. That's just common sense on the engineering side. I'm sure the actual Technics amplifier circuit is quite compact as well- my guess is that because of its very high switching speed, its even more compact!
’Dinky’ in this part of the world means ’small’.

Like I said you know exactly what I mean, and yes it means the same in Au. I’m talking about dinky ones the size of cigarette packet, some that can do 120w sometimes with external wall wart smp supplies, some that are shilled on these Audiogon pages. I would bet the 54kg Technics SE-R1 would eat them alive same wattage. at 8ohm
I’m not talking about wattage Ralph, and you know that very well, give up and try not to go into product protection mode, when ever GaN is mentioned.
This comment does not make sense when compared to
The ones around now using GaN’s are either dinky little office type class-D’s or expensive ones that haven’t utilized the technology as far as Technics did.
'Dinky' in this part of the world means 'small'.

And since you chose to make the usual ad hominem attack, can you get it that we've been working with GaNFETs in most of our prototypes except the very early ones? Why not, they're quite inexpensive!
This thread will be closed if the bashing between Eric and George don't stop. 
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Hmmm, just wondering if it is OK if I continue to enjoy the performance of my Bel Canto amp in my system.

@mlsstl 
To hear George tell it, you have to put it on a test bench, and after looking at the scope's output, you'll suddenly realize ....

I don't know what. Actually I have no idea what his point is.

Hmmm, just wondering if it is OK if I continue to enjoy the performance of my Bel Canto amp in my system. 
This statement is false. The Technics amplifier is only 150 watts, which is similar power as many of its GanFET competition.
I’m not talking about wattage Ralph, and you know that very well, give up and try not to go into product protection mode, when ever GaN is mentioned.
And the $20K I mentioned for the Technics SE-R1 is around the Au $ price
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The ones around now using GaN’s are either dinky little office type class-D’s or expensive ones that haven’t utilized the technology as far as Technics did.
This statement is false. The Technics amplifier is only 150 watts, which is similar power as many of its GanFET competition. 
intrawert6 posts02-24-2020 6:10pmWhat’s up with GaNfet? Let’s discuss new items. I think this year will be a breakthrough, thanks to new technologies.

Gan fets are definitely the future for Class-D or any class, if their used to their fullest like Technics did with the SE-R1 higher switching speed (1.5mhz) and higher output filter to suit, so there none of the problems it has now. But the SE-R1 is >$20k
The ones around now using GaN’s are either dinky little office type class-D’s or expensive ones that haven’t utilized the technology as far as Technics did.
New ones from  https://www.classdaudio.com maybe will be good for the money, but I don't believe they went as far as Technics did with it. this is the GaN site  https://www.premium-audio.com/    

Cheers George
"georgehifi....Do all the cobwebs that root you to your chair bother you?Just wondering.....;)"

Once again....

(Moderator, please note.  The above is not obscene, nor anymore of a 'personal attack' than what had already occurred previously.  Just an observation, and MHO.  Thank you.)
George
" Put them on the bench yourself and see, if you even have or know how to use bench test gear, which I strongly doubt very much the way you carry on."

I don’t care WHAT the bench test are, or say. I care what my ears say. The dynamics, the floor, impact at nice volumes. I get this theory from my 20 years of racing cars. NHRA Superstock. Horsepower is everything right? Wrong. Its the "package" of all the parts together that counts. And those dynos we test our engines on mean nothing. They ( sometimes) lie. They are just a test. A benchmark so to speak. The REAL test is the time ticket, the results. Bottom line, am I, or anybody else, going to be able to hear this issue you keep harping on?


"It's time to invent penicillin for hi-fi. "

*L* Yeah, we take drugs seriously at our house, too...;)

"Is your A amp on 'downers'?  Is your family staying away from the highfi?

Well, Today's Your Lucky Day!"
What's up with GaNfet? Let's discuss new items. I think this year will be a breakthrough, thanks to new technologies. It's time to invent penicillin for hi-fi. Thanks to the progress..
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Still can’t see the forest for the trees yourself, parroting BS spoon fed to you by others, probably that have commercially involved instead of looking for yourself.

Put them on the bench yourself and see, if you even have or know how to use bench test gear, which I strongly doubt very much the way you carry on.

Over and out
erik, et all


let’s stop feeding the troll. He is clearly lonely for attention, apparently of any kind, and knows how to push our buttons. In my case at least I am officially no longer giving his comments the time of day


Do we have an Ignore feature?
@georgehifi

Looking forward to your complete retraction of your false claims regarding Class D and output phase.

I will be kind and suggest that you going "wow, I'm sorry, that was incorrect" is going to be a lot easier on you than me writing up a post about why it's wrong.

Really, fixing your own mistake is going to give you character.

Kisses
You've lost it sunshine, you had more cred when you were bagging Pass Labs.
I don’t know George, you are swearing, resorting to personal attacks and failing to answer your technical mistakes.

Maybe bashing Class D all weekend long isn’t your most productive use of your time??



Boooomm!! thar she blows, your https://youtu.be/YTY26k0CA0I?t=5

You named this thread "The Truth about Modern Class D"
like you had some secrete insight to something special about Class-D, that no-one else knows, there isn’t sunshine.

And I didn't revitalize ****, it was a 2 poster  markw1951
BTW, George, thanks for helping to revitalize this thread. I haven't seen it for months, then 1 new post shows up and your incessant bashing Class D keeps this thread at the top of the list for Audiogon.

This would be a dead thread if it wasn't for you.

Kisses
Wow what a rant, clean up aisle 4

@georgehifi

Looking forward to you recognizing your technical errors and retracting them.

yes you are known as an Pass Labs basher


George, you have bashed Class D more in the first page of this thread than I ever mentioned Pass (the name or the brand). In fact, all over Audiogon, one cannot mention Class D without you jumping in. You are exactly like Beetlejuice (the movie).

So, in this thread, recently, you’ve failed to recognize your technical mistake, took a condescending attitude towards another audiogoner and insulted me, also, you’ve lied about me. Talk about a lack of respect.

I am looking forward to the time when you are shown the technical errors in your argument and you actually don’t turn it into an excuse to attack another.

Kisses
Wow what a rant, clean up aisle 4
Your going to blow your pooffoo valve sunshine, better keep in in check, and yes you are known as an Pass Labs basher
Golf, that **** doesn’t worry me, I just hope the mods see it and treat it for
what it’s worth. He’s a Nelson Pass basher, we all know it.

So, @georgehifi you had a post of mine which laughed out loud at you removed because you felt it was too insulting and classless, but calling another member an idiot is OK? Also, if you are talking about me, George, I have never bashed Nelson Pass, and I daresay I have never bashed the brand. I don’t like it. I’m allowed to not like something, right? Because god knows you have half the posts in this thread talking about Class D being terrible.

Also, relevance?

I started this thread hoping to get members to be open minded and let those who enjoy Class D chime in. Instead it has become a character study. Anyone who takes you at face value should read the entire thread. I stand behind my behavior.

Best,

E

There's a handful of people on A'gon who need Class D amps to fail, and then there's dozens of us who enjoy it every day.

:)

Erik
Once you’ve made your point, time to move on, but noooooo. Seems like every time someone posts something positive, you have to rush BACK in and spew your ’knowledge’, for which people who actually understand the electronics, have to correct you, yet again



@tweak1 :

To use GFi’s exact condescending words against him: "You just doesn’t get it, george."
Maybe I'm being naïve, but I just can't believe that Legacy would put out all this hoopla, video's, and power their state of the art systems with something "flawed". The proof is in the pudding, and I'm coming from what many would consider an amp right up there at the top, ATI Signature Series 6005. I play my system at spirited levels, so the dynamics, punch, and headroom are important, So as to my wanting to try this new IV*5 amp. Maybe the nay sayers are right, but the only way to find out is try one. Just like tweak said.   
gFi


I started it? You’re the one who keeps dumping on class D, including Rics, which he has pointed out a couple times that his has a significant number of modifications.And your response "YEAH, SURE"


Once you’ve made your point, time to move on, but noooooo. Seems like every time someone posts something positive, you have to rush BACK in and spew your ’knowledge’, for which people who actually understand the electronics, have to correct you, yet again


And "I", as very happy EVS 1200 camper, with quite a few amps under my belt feel compelled to respond
@georgehifi

Oh wow, for some one who routinely attacks other A’gonners personally you are very very sensitive fellow.

So, lets stick to facts:

You just don’t get it tweak, this is why many find the upper mids/highs objectionable on Class-D, why would I want to listen to an amp with this much phase shift already 25 degrees! at 2khz, and it get’s progressively worse all the way up to 70 degrees!!! at 10khz.

You are completely misreading the data you posted.

As I posted before, the chart you are showing is the phase angle of the output impedance, not of the audio signal. Look at the datasheet for the 250 ASP, which actually shows the phase angle of the audio signal itself.

As I also posted before, most experts agree that phase angle doesn’t mean that much, so even if your horrific misinterpretation of data was accurate (and it is factually wrong) I doubt anyone would hear it.

https://audioxpress.com/article/zero-phase-in-studio-monitors

Some one who had integrity would strive to correct errors of fact when possible, instead of attacking the character and taste of those who disagree with him.  Please, show us your mettle.

Kisses.

George, his post should be removed for crossing the line in offensiveness, and he should be given a warning, if not banned.
Get a life


Tweak you started it again, I told you, every time you bring me in by name, I’ll put up the phase shot of the Icepower amp.

Golf, that **** doesn’t worry me, I just hope the mods see it and treat it for what it’s worth. He’s a Nelson Pass basher, we all know it.
Cheers George