High end Class D amps?

Typical response from a fuser. 
https://i.dailymail.co.uk/i/pix/scaled/2013/12/18/article-0-1A2B262D00000578-818_636x382.jpg

GaN is already here with Orchard, AGD and others, while the much-delayed and much-anticipated LSA Voyager is reportedly coming soon (perhaps).

And mid Feb so they say, the integrated with everything, the SU-R1000 from Technics promises to be the pinnacle of affordable Class-D design using GaN technology, and "hopefully using the same as their flagship SE-R1 1.5mHz switching speed" which should take it to where Class-D promises to be, but hasn’t as yet..
https://forum.audiogon.com/discussions/technics-su-r1000-a-new-class-d-gan-technology-integrated

Cheers George

A real sleeper, very powerfull bi-polar, hard to find in good nick, and can be cheap, because it’s not in audiophile circles. https://www.usaudiomart.com/details/649216490-yamaha-p2200-p2200-power-amp/
Get hold a good condition Yamaha P2200 a bias it up 2 x as much Class-A as they can take it, they made them for band use to be very rugged.
And they use the very best, expensive, Alps Black Beauty volume pots, so feed your dac direct in and use them, a killer linear power amp.

https://ibb.co/s5T05Z5
https://ibb.co/wWtwf4r

Cheers George

A very expensive ($12,000usd) active 2 way speaker, with questionable origins for the class-D module inside.

Looks very to me, like it could be one of the 50 odd different subwoofer/PA modules Sanway makes, has a very similar layout to them all, time will tell when a pic of one comes up.
https://ibb.co/61hrMyJ

Cheers George

The modules in your photos are not the modules in the Dutch and Dutch

So your saying you can get a pic of the modules in the Dutch and Dutch so you can post one up???

If not then time will tell when we finally see a pic of the module, if they are not the Pascal M-Pro2 made by Sanway China, that are used in the Rowland Research and Red Dragon amps. 
We’ll have to wait and see what they are, to see if Pascal are capable of making their own modules instead of using Sanway or any others, as they have done.

Cheers George

^^ Really did you open one and look at it?

Really!! did you even look!
A blind man with "minimal" tech skills can see they are the same manufacturers subwoofer modules from Sanway who sold them on Alibaba for $100 each

As an example the Dutch and Dutch 8c uses Pascal after testing various modules because they could get them for a better price and couldn’t hear or measure any difference. I believe Buchardt uses Pascal as well.

They are not Pascal’s modules, like ricevs fiddles with Ice modules, they are tweaked by Pascal, but are $100 Chinese Sanway subwoofer modules, as I’ve shown before with identical pictures. That Rowland Research and Red Dragon also use.
https://forum.audiogon.com/posts/2085585

Cheers George

You make it sound like the Wilson Alexia is the most popular speaker on the market.

No, I use them as my friend owns a pair, he's reviewer, so we get many amp to try on them, and they are one of the the most difficult speaker to drive,  especially for Class-D,  as they have an EPDR of just 0.9ohm in the bass.

It doesn’t matter. It puts out 500 watts into 2 ohms. That’s enough for most users. I consider "doubling" an irrelevant factor.

Then next you lot may as well just tell us to use this 6000watt!!!!! Class-D Behringer for just $600us.

Let me tell you, that on the Wilson Alexia in an a/b it was trounced by the 40 x times less powerful!!! Gryphon in dynamics and bass control. The Behringer was thin, anemic, weak in the bass and sounded like it was struggling
https://www.bhphotovideo.com/c/product/1427354-REG/behringer_nx6000d_6000_watt_class_d_power_amplifi...

Look at the specs of the PuriFi modules, which can put out 500 watts into 2 ohms with 0.0003% THD.

Look at what independent tested current it can do.
Compare the "2ohm wattage" to the "4ohm wattage", and see if the 2ohm can come "close" to doubling the 4ohm, if so there’s no current limiting.
If it’s similar or lower, then there is severe current limiting/sagging.

Cheers George

Isn't class D just prepackaged class ab?

Na, they're HF power oscillators that try to make sound.

Cheers George

Your source better have low output impedance as well. The NC500 modules are fairly low impedance on the input.

Any one don’t be scared off doing this if your source is up to the task, 2k input impedance for the NC500 is not so bad, many retail class-D amps are that anyway.
Even a 50ohm source impedance is fine into that, most high gain good dacs are contenders for this hook up. And the best buffer is no buffer.
My dac is 1ohm output with 200mA short circuit current, nowhere near full volume, absolutely no problem . 

It looks like in the Dragon they use the NC500. I assume they’re doing what every other manufacturer that uses this module they’re adding their sound with theirs or a third party external buffer.

Or even better if your source has balanced output and enough gain, feed it direct into the NC500 amp modules with no buffers at all, like I did, with my NC500 monoblocks. This is the least distortion and most transparent/dynamic you’ll get

Cheers George

bluorion OP gdnrbob
As I said your Lux is more than fine for that speakers load and probally better than any Class-D.

But if your insistent on getting a Class-D, I’d wait for mid February to see what this new all out Integrated is all about, and if it follows the design set by their Flagship poweramp, it will be something special.
https://forum.audiogon.com/discussions/technics-su-r1000-a-new-class-d-gan-technology-integrated

Cheers George

djones51
The Luxman is more than enough to drive those speakers.

Ditto. bluorion OP
Just look at the impedance/phase curves, absolutely no problem for the Lux, and it will sound better that any class-D on them, to boot.
https://www.stereophile.com/images/918DS40fig01.jpg

Cheers George

Class D is coming of age.

Yes when you have this sort of GaN technology with Class-D amps like the flagship Technics SE-R1 with it’s 3 x higher 1.5mhz switching speed, to fix the Achilles Heel of all class-d’s, in the upper mids/highs that many complain about after living with them.
And hopefully they’ve carried this switching speed onto their new integrated flagship, yet to be released (Feb-2021) SU-R1000 Integrated.
https://forum.audiogon.com/discussions/technics-su-r1000-a-new-class-d-gan-technology-integrated

Also the linear Soulution Amp
135W into 8 ohms
260W into 4 ohms 
490W into 2 ohms 

Not many Class-D's have I seen JA do 2ohm loading wattage figures on, in fact can't remember any.

Cheers George

Michael Fremer says it drives the Wilson’s very well? I have not read the review yet. OH NO, this cannot be. George will never talk to us again.

You believe Fremer on any PS audio product? good luck with that

I see a slight problem in Michael Fremer’s review of the PSA amps...he and Paul McGowan happen to be very good friends...so..for reality’s sake...I would take that review with a grain of salt.

You can say that again.

JA bench tests found this PS Audio amp’s distortion rises very quickly into 2ohms, about 3 x higher even only at 1/3rd it’s output power, would be nice to see what the distortion would be then with the Alexia’s 0.9ohm!!!

And as for wattage power tests into 8 and 4ohms yes it does well, just like any Class-D, but JA didn’t post up any test or mention into 2ohms, and you can only guess why, as he nearly always does with linear amps.

JA
Like he did with the smaller A-Class Gryphon Essence poweramp
8ohms 53w (all in Class-A)
4ohms 101w (said to be all Class-A as well)
2ohms 182w

Cheers George

 'naturally balanced'.

This statement is not correct!
And as far as Laverda's go your lucky to keep your fillings in your teeth after a ride.

Moto Guzzi's  feel very similar to the BMW horizontal flat twin vibrations, both are no-where near as smooth as he V Twin Ducati.
 

Ducatis and Moto Guzzi as you know share the same top end angles between their cylinders so vibration harmonically cancels; i.e. 'naturally balanced'.

This statement is not correct either. Ducati's V-twins are perfect balanced because of the counter weighting that can be done (my mistake saying they were "naturally balanced")

Ducati:
The first thing is that Ducati V twins have or 90 degrees. This uniquely makes it possible to balance a 90-degree twin with counterweights of 100 percent of one piston's shaking force.

Moto Guzzi: 
"There are two aspects to our Moto Guzzi engines. One is that they are "fairly" vibration free compare to some other twins (like HD and old British twins) but "they still have secondary vibrations". But that is also separate from the side to side torqueing vibration of the motor that is more noticeable when you get on or off the gas but is always there." "Guzzi parts are not well balanced and the transverse layout also contributes...the late, great Gordon Jennings felt that transverse engines seem to vibrate more.."

Ha! Photos or it didn’t happen.

Really more digs? You are the pits Ralph.

None of the 750 Sport as yet all it’s in bits in my workshop, but here are two shots of my Desmo 900 Super Sport I also restored slightly modded, and sold 10 years ago.
https://ibb.co/sw59hSw
https://ibb.co/vmR8gbH

As for Moto Guzzi, they’re ok, had one of them also, a 1000 sport, same as this but black
https://mcn-images.bauersecure.com/upload/967/images/1440x960/166690@Moto-Guzzi-1100-Spor.jpg?mode=m...
nice looking built like a tank, but they ride like a tractor with their odd vibration, not being naturally balanced. The Ducati’s are superior in all departments that matter to a rider.

George - You’ve brought up this notion of EPDR in several class D threads, but haven’t explained how it relates to class D.

It relates to any amplifier seeing the low EPDR loading which demands extra current to be delivered from the amp, which Class-D’s don’t do as well as good linear Bi-Polars can.

Obviously, you can contrive a situation where a given class D amp does not have the current capability to drive a particular load

I don’t contrive anything, it’s fact Class-D can’t do current into low impedances like good linear bi-polars can, and if you don’t believe or have the knowledge to understand that, it’s your problem not mine.

Now excuse me I’m going back to the workshop to finish off my 1973 Ducati 750 sport (round-case) engine main bearing replacement.

And Ralph in the below post below, it’s just not the GaN transistor wrong yet again, you forget the output filter and feedback also.
Just leave it be Ralph, anyone can see your in "product protection mode" your not doing yourself any favours.

So explain how an amp with an output impedance of 10 milliohms

Just like a Technics Su-G700 Integrated GaN Class-D with it’s milliohm output impedance also can’t drive the Alexia load either!!! It’s got the so called wattage at 4ohms

Back to the Duke, more important than talking to shillers of their own yet to be released amps. 

No you have no idea, or, as I said you are in "product protection mode" and need to say the opposite for your future release. Most probably the latter I would think.

I’ll state once again as yet NO!! Class-D (and that also goes for my choice Class-D Technics SE-R1) will perform as good into a pair of Wilson Alexia and such, with their EPDR bass loadings like a hi current Gryphon Antillion etc etc can.

This statement is blatantly false. Class D amps are limited in their ability to play low impedance (and severe phase angles) in the same manner as traditional solid state,

No it’s not, and you know it and are in denial, your just once again in "product protection mode for your yet to be released Class-D".
 Just try to get any Class-D to perform as well as an amp with bi-polar output like a big Gryphon's into a pair of Wilson Alexia’s, the Class-D will be shamed.

I’ve noticed that they do tend to truncate the natural decay times on bass notes, which I believe is due to their very high damping factors.

For those that want to know, I believe "that experience" is more likely because many speakers have there lowest impedance in the bass and also their highest -phase angle.
Combined, these two give’s you what’s called EPDR, (Equivalent Peak Dissipation Resistance) and that can give the amp a very nasty load impedance to look at.
Good big current bi-polar amps don’t mind seeing this
.
Class-D tends to quickly drop off it’s current starting under 4ohms down to 2ohms, look at any Class-D "independently measured" spec and you will see that, they never come close to doubling wattage from 4 to 2 to 1ohm, many even go backwards, showing severe current limitations into low EPDR impedances, this is limiting bass performance and becoming like a tone control, rolling off the bass instead of staying flat to 20hz.
https://www.audiosciencereview.com/forum/index.php?threads/stereophile-has-started-calculating-epdr....

This link also on EPDR on the second page:
https://www.stereophile.com/reference/707heavy/index.html


Cheers George

Most toroid transformer manufacturers supply mounting hardware, and if you use it the transformer will run hotter than it should. This is because the mounting bolt is steel

A least that’s one you got right and we can agree on, this has been known btw forever since toroidal’s were first released, and especially when the bolt is in contact with the chassis earth, sorry but you did not discover it. (so no self back pats) My Hungarian EE boss (rip Steve De’Ratz) back it the 80’s told me about this, as his family tree had something to do with the first ones. And it also applies to any air core chokes, in speakers, amps, anything.

Can't loose then with 30 day trial, just like getting any Schiit product 14 day trial.
Be nice if Technics did it with the SE-R1, but to even buy one of those is very hard.

Cheers George  

What about Techics GaN based class D amps, are there others who use GaN?

Yes, but none yet "so far" that have taken the full major advantage of the 1.5mhz switching speed on offer when GaN Technology is used, that Technics does with the 188lb SE-R1 that also uses linear power supplies, input ones are regulated.

https://ibb.co/S6CFz5y

https://ibb.co/wwH0vNr

Here’s a little to read on the GaN transistor and it’s higher switching speed ability, that Technics have used.

https://www.psemi.com/newsroom/pres...fastest-switching-speeds-to-gan-class-d-audio

Cheers George

That’s all your good for, taunting. All can see that .

https://youtu.be/YTY26k0CA0I?t=5 sorry but that it for you.

Give it a break mate, and find something else to do.

Please come back and let us know after you’ve lived with them, as from what I’m told they are the ICE 1200 modules like @tweak1 uses (he’ll be happy) but with a tube input buffer.
Look at the graph and say if you can hear a disconnect of sound signature with the phase shift above 1khz.
( red trace https://ibb.co/NC7sC8T )
like I can with my big linear phase ML ESL’s with Neolith panels

Cheers George

And there you have it folks.

You have nothing but your ignorance and being a fuser, and your persistence in the future shilling of whatever Class-D project you seem to have, could be with an old OTL maker the way your so persistent with wrapping him in cotton wool.

Find out yourself sunshine, why should bust my ***** trying to explain to a brick wall. There’s plenty to read here.
Educate yourself, 3 pages of it. for you to "try" to understand maybe?
https://www.stereophile.com/reference/707heavy/index.html

Maybe you can't teach an old dog new tricks.

That's more like you can't teach an old dog bad tricks, which is all your spruiking.

You have no idea and do nothing but put **** on anything that's not "pro" Class-D.
It still has problems sunshine, compared to the better linear amplifiers I and many other still say so.

You are nothing but a Class-D flag waver, that I believe probably has an commercial interest either now, soon or in the future with it.  

George - you obviously aren't interested in class D, so why do you keep bothering to post on this and other class D threads?

Really, you need to look a bit deeper sunshine, before ragging on someone.

https://forum.audiogon.com/posts/2062498

Problems with any amps shouldn’t be fixed by using even more feedback as a fix, it’s a added by the best designers to clean thing up a little and usually just local not global in an already well designed amp.

All the greatest amp designers say it. An amp should be reasonably good spec’d, and to use it just as a clean up tool.
And the preference with the best is to use "local feedback" only by the best designers. Not global as being talked about here, and then even including the Class-D output filter in the global loop, what next throw the speaker wire and the speaker in the loop as well, like Trio/Kenwood tried all those years ago, utter sterilized disaster sound.

And using tube buffers with the capacitor coupling that’s needed. Is just colorized HF coverup softening job for the more serious Class-D sound problem.

Cheers George

jaytor I think I stated earlier in this thread that I used to own a pair of Nord Hypex NC500 monoblocks.
In the past year, I’ve had a lot of fun building DIY electronics (two pairs of monoblock amps and a preamp so far), so I’ve decided to try building a class D amp as my next project. I like monoblock amps for a number of reasons, so this project will be another pair of amps. I’m using the Purifi modules, and using a high-current linear power supply (1500VA) for each amp

Interesting as this is what I have with a monoblock pair of NC500 modules.

Which impressed me and are in the Belcanto Ref 600M’s for class-D driven into a two way with Rahl ribbon, a very easy benign 6ohm load.

So these NC500 module (which btw are the ones in the Belcanto Ref 600M’s) are also in monoblocks but using big linear supplies and fed direct to their balanced input their input via the MSB R2R Discrete’s balanced variable 10ohm output so no need for any input buffer board. These sound even better than the BC Ref 600M’s. On those Rahl based two ways.

On the main system these NC500 mono’s have great bass/mid bass (very low bass is still bettered by my big ME bi-polar linear monoblocks with more weight substance to it) same as this amp but set 30w bias and no Class-A switchablity.
https://ibb.co/QnYhmzL
https://ibb.co/zb8vCgR
Upper bass is the equal of the ME’s as is the lower mids (male voice). And then this is where the bigger difference starts, there seems to be a disconnect in the upper mids and highs from the bass with the NC500’s like they are two different amps doing bass and mid/highs.
I’m putting it down to the switching frequencies output filters phase shift that reaches down to 1khz!!!! as can be seen in the phase shift plot in the graph of Class-D’s https://ibb.co/NC7sC8T which in this case is still -25 degrees at 1.5khz!!! and -75 at 10khz!!!!!!!

And this is why $$$$$ Technics with the GaN based, linear supply, SE-R1 I believe have the answer by increasing the switching frequency 3 x’s to 1.5mhz so then the filter can also be raised by the same amount and hence the phase shift goes up by 3 as well out of the audio band.

Cheers George

You have absolutely no idea, your burying your self with your own brand of **** ****

George is coming from a position of near 0 experience

Really??? so you think a Class-D with a tube rectified power supply and a chassis stuffed with pillow fill is the answer to the woes Class-D has?. Good luck with that sunshine.

I tried to tell you the answer, with higher switching frequency (3x the norm at 1.5mhz) using GaN output transistors as Technics did with the $$$$$ SE-R1 so that then switching frequency output filter can then be set also 3 x higher thus stopping any phase shift down to 1khz as it is now with all Class-D’s
  
As for driving low impedance combined EPDR even lower, not even the GaN can compete with bi-polar A/B amps there, they still rule the roost.   

Cheers George

No, no, it’s not the Tri-Art class D Amp

Yeah well that’s a beauty

True, I can take that one both ways.
He does trash his reputation when he’s product protection mode, as there's not much new tube amp sales going on anymore.

I currently don’t make, sell, or market any amplifiers and have no skin in the game either way.

You are delusional, I didn’t say you. Go back and read.

But then you are a 50’s kind of guy and you don’t hear too well anymore

George, as a simple tip: the ability to admit that you were wrong is a strength, not a weakness.

Ralph lay off protecting, you do the same with preamps.

The answer is simple: Gain knowledge instead of made up stories.

These are words of someone either in denial or in product protection mode.

And there it is, Ralph's new Class-D release must be soon as he's gone into full product protection mode.
 
How can anyone believe that "any" Class-D driving a pair of Wilson Alexia etc etc could possibly do anywhere near the sonic job that an amp like Gryphon Antllion or similar could do.
Especially in the lower bass where the Alexia's are 0.9ohm loading presented to the amp.

Cheers George

This is very basic stuff.

Which I sorry to say you don’t understand.
If you knew the difference of current ability between complimentary Mosfets v complimentary Bi-Polars into low impedances like the Alexia’s etc etc we wouldn't be having this, and you will see how misguided YOU are.

And as for the title to this thread "High end Class D amps?" here is the only answer so far to that title
https://forum.audiogon.com/posts/2057327.

I will state again. You clearly do not understand what this term EPDR means.

You have no idea, https://imgbb.com/Zzsqsr0 
If you have, stick one on your test bench and watch what happens with the same input to the wattage figures under 8ohm 4ohm 2ohm and 1ohm loading. Until then please take a pill, and push your Class-D out there beliefs to ones that will believe it.

It has no application to Class D amplification.

Of course it does show if it’s capable of driving it.

I suggest going back and understanding this better as your understanding is flawed.

No, I suggest you go and find out what happens to Class-D when it tries to drive low impedances that I’m talking about, see if it can do the wattage doubling act down to 1ohm or even 2ohms as the impedance halves They are lucky to even gain any wattage below 4ohm, they usually start to go backwards especially at 2ohms which is current starving or limiting.

And if you deny that, show some independent test figures of class-D wattage at 8ohm, 4ohm, 2ohm, and 1ohm

I will repeat my question, why would a class-D amplifier care about phase angle.

I’ll repeat my answer in another way, negative phase angle combined with low impedance can as in the Alexia, gives a EPDR of load as seen by the amp of 0.9ohm load!!!!
Now you go find a Class-D that will keep pushing even more current into that kind of loading like a good bi-polar amp can.

If you can hear it at a shop with speakers like the Alexia you'll be stunned at what just a good 100w bi-polar amp like Gryphon v any Class-D of any wattage, the Gryphon will be superior at those EPDR frequencies in the bass.
 
Cheers George