[Trismos]

I didn't read through the whole thread, it's fairly large. Is there mention or comparison between the D amps and T amps like the Virtue M-901?

[Freo-1]

There are links throughout thread which refer to various topics related to those types of comparisons.
 
I read the most recent tech papers on the N Core, and it is still a bit light on what’s going on regarding smoothing out the HF portion.  The section on negative feedback is interesting as well, as somewhere along the way, there must have been some criticism about its usage.

[OzarkTom]

Here is another Class D amp that has gotten a rave review.

http://www.innerearmag.com/reviews/amplifiers/Genesis_2point2.shtml

Quote: "I suppose, that Class D amplification has reached maturity with the Genesis Reference Power Amplifier the proof of this accomplishment. It brings together technology and musicality and eliminates the myth that Class D amplifiers are only good for bass. My take on technology is that I don’t care about it from the technical viewpoint, but appreciate greatly what it can do for the industry I love, the music — and me. Great job Gary."

Here is another rave from 6moons, the amp received a Blue Moon award.

http://www.6moons.com/audioreviews/genesis5/reference_5.html

[Freo-1]

Here is another Class D amp that has gotten a rave review.

http://www.innerearmag.com/reviews/amplifiers/Genesis_2point2.shtml

Quote: "I suppose, that Class D amplification has reached maturity with the Genesis Reference Power Amplifier the proof of this accomplishment. It brings together technology and musicality and eliminates the myth that Class D amplifiers are only good for bass. My take on technology is that I don’t care about it from the technical viewpoint, but appreciate greatly what it can do for the industry I love, the music — and me. Great job Gary."

Here is another rave from 6moons, the amp received a Blue Moon award.

http://www.6moons.com/audioreviews/genesis5/reference_5.html

 
It’s good to see more positive feedback regarding Class D amps.  How the amp works is of interest to me, so given all the processing required to get a output from Class D, am keen to work how these smart engineers address the challenges associated with it.
 
I do take reviews with large grains of salt these days, as it’s been a long time since I actually read a negative review about any piece of high end audio equipment (they are fun to read, though). 

[dreamtheatervn]

This topic is really interesting but was stopped for long time. Since then many changes, is the Ncore still game changer? How's improve of Class D? Why recent many sells for Ncore based amps in the trading post?
Appreciate if someone can tell us what's going on with Class D...

[motosapien]

I moved from a  NAD 365BEE at 150 watts per channel to Class D Audio kit at 250 wpc.  Been listening to it for a couple months.  It has fuller more lively bass but in a subtle way.  The mids and highs are comparable to the NAD.  Not harsh or shrill at all.  I use normal cables.  It sounds the same with all my sources inluding pc based digital through a modi dac and tube processor.

If I were looking to upgrade I would build a single ended class a amp.  I have a speaker project underway that should come in at 93 spl so a lower power amp would work well.  The class d amp can be used for bi amping the bass drivers.  If you've got fairly efficient speakers you might consider a Pass Labs Aleph J diy build - can be done for under $1000.

The reason I would move to class a is just curiosity and something to work on, which is the reas8n most of us gear heads like to switch things up.

[barrows]

I think it is worthwhile to keep this discussion going.  First, many audiophiles are tinkerers, and are constantly changing components-I suspect this is the reason we see Ncore based amps (and others) come up for sale quite often.
I have had a DIY NC-400 amp in my stable for over a year now.  "Game changer"... well, I prefer to refrain from using hyperbole.  If I had unlimited resources, and electricity use was also of no concern to me, I would probably own massive, pure class A monoblocks like Pass XA 200.8s or a big pair of Vitus amps, but I cannot afford those, and I do not want to pay the electric bill for them either.
I can say that I have decide to sell my Pass X150.5, as the Ncore at least equals it in my system, and is much more resource friendly.  One thing I will say, is that the Ncore is better than other class D of my experience (I have heard many ICE implementations, as well as a couple variations on Hypex uCD tech) as the Ncore does not have that slight lack of air and extension in the upper frequencies which seems to plague other class D designs.  If one is looking for an amp that will add character to a system, the Ncore is not what you want though, to me it is a clear window on what is going on elsewhere; I use a DIY DACs, so I feel I can hear exactly what is going on in my DAC with the Ncore, and if want some "character" in my system I can get it by making changes ot the DAC.
As for feedback, well this is a controversial topic for sure.  My understanding is that feedback in class D should not be considered the same way it is for traditional A-A/B amplifiers, as the feedback loop operates at a higher rate of speed-I hope actual class D engineers might comment on this, because I am not sure about it.
From what I have heard, only very best class A amplifiers offer anything which I would consider an advantage over Ncore amps, and those class A amplifiers are many times more expensive than even really nice Ncore implementations like those available from Merrill.
Of course, if you are lucky enough to have very sensitive speakers which do everything you need, you might be able to get by with something like a Pass XA 30.8, if I had speakers like that (>91 dB and 8 ohm nominal) I might try a XA 30.8, or refurbed version of one of the balanced input Aleph series amps...

[DaveC113]

I just listened to Pipedream line arrays with dual subs containing two 18" drivers per sub.

It used to have a $16k Atmosphere tube amp but it was retired in favor of.... wait for it.... two brand new Crown class D pro amps. He uses this system for large scale / rock and has another system for "smaller" music, he said the Crowns blew away the Atmosphere amps, said it wasn't even close.

His Pipedreams system is one of the best I've heard and sounded spectacular. The Crowns go for around $500 each.

[playntheblues]

Dave what Crown amps were those?

[Russell Dawkins]

I just listened to Pipedream line arrays with dual subs containing two 18" drivers per sub.

It used to have a $16k Atmosphere tube amp but it was retired in favor of.... wait for it.... two brand new Crown class D pro amps. He uses this system for large scale / rock and has another system for "smaller" music, he said the Crowns blew away the Atmosphere amps, said it wasn't even close.

His Pipedreams system is one of the best I've heard and sounded spectacular. The Crowns go for around $500 each.

I'm guessing this partly underlines the advantage of really having "enough" power on tap as much as the specific quality of the Crown amps being better. I think for many the only access to cheap power is the pro amp field. It is for me.

[Freo-1]

Since this thread started some time ago, I’ve tried a few more Class D amps along the way.  One of them was the Yamaha MX-D1, which was an excellent sounding amp.  It sure was nice to have the 500 watts on hand.  It did many things well.  The circuit topology remains state of the art with current Class D amps, and had a number of propriety aspects to the design.  The amp drove the ATC-SCM19’s quite nicely, and could drive them a couple of db higher than amps with less power.  I think many people could easily live with the MX-D1, NCore’s or similar Class D types of similar quality.

In absolute terms, my preferred amp/preamp setup is a DIY tube setup, with a Thomas Meyer design 6AH4 preamp, and a pair of 1625 mono power amps.  Close behind is an Electrocompaniet EC 4.7/AW2-120 power amp combination.  Both the tube setup and EC setup sound a bit more natural overall compared to the Class D.  The Class D amp sounds more 2D, and low level detail just does not sound quite as clear.  The tonal balance from the tube setup is very seductive, and the EC gear is very accurate, with outstanding low level detail.  Granted, it’s not a big difference, but it’s a difference that is picked up pretty quickly.  The Class D amp gives me listener fatigue over time.  The tube setup provides NO listener fatigue, and the EC setup has very little listener fatigue. 

Disclaimer:  These are personal observations with the ATC-SCM-19 speakers (and SVS SB13 Ultra/ATC C1) subwoofer setup.  I think the speakers make a HUGE difference, and I could easily see with different speakers that audiophiles would rank the amps differently.  The ATC’s are very precise, and not everyone would prefer their presentation.  They also need 50 watts or more to sound their best. 

[Randy]

Those of you interested in a Class D amp should check out Aluminati right here on Audio Circle. I have their X2, and it is superb. Complete info on the Audio Circle site or at their webpage.

[DaveC113]

Dave what Crown amps were those?

I just checked with him, they are the XLS DriveCore 2000s, he's running them bridged and full-range for the mids. He's got a pure class A SS amp on arrays of ribbon tweeters that were retrofitted to the Pipedreams to replace the stock dome tweeters and another pair of older Crown amps running the two dual-18" subs. A Pass Labs active crossover feeds the amps.

It comes out to something like 3600 watts per channel. 

He said the Crowns "destroyed" the Atmosphere tube amps in all areas except a touch of midrange bloom provided by the tubes.

This is a serious system with top of the line source and preamps, his vinyl setup is worth around $25k itsself... the Crowns reminded me alot of NCore 1200s that sell for $9500+

And, you can get the amps for as little as $431.13 online, $499 being a typical "street price"... without bridging them they are "only" 375W into 8 ohms.

He also said his buddy with Maggie 3.7s (I think that's the right model ?) had the biggest Pass Labs amp on them and the Crowns easily beat out the Pass Labs amp!

Then we have the low-powered TI amps being sold for under $100 beating out basic SET amps in the $1-2k range...

[DS-21]

This topic is really interesting but was stopped for long time. Since then many changes, is the Ncore still game changer?***

It never was. It's a superbly measuring amp design, to be sure. There's nothing wrong with preferring to support the state of the art, even if the superior measured performance means squat in terms of audible differences.

But sonically the best one can say about Ncore (or UcD for that matter) is that an amp competently utilizing one of the Hypex modules sounds exactly like a competent AB amp while offering large improvements in energy efficiency and power/size ratio.

[I.Greyhound Fan]

A friend of mine brought over his NCore Mono blocks to my house to run with my Magnepan 1.6's and they sounded dull and flat compared to my Pass X250 amp.  He got rid of them in favor of an AVA 400R which is much more musical and dynamic.   I also have a Class D CDA 254 kit amp that sounds good but not as good as my Parasound A21.  It has more air and transparency than the A21 but thats about it.

[jtwrace]

A friend of mine brought over his NCore Mono blocks to my house to run with my Magnepan 1.6's and they sounded dull and flat compared to my Pass X250 amp.  He got rid of them in favor of an AVA 400R which is much more musical and dynamic.   I also have a Class D CDA 254 kit amp that sounds good but not as good as my Parasound A21.  It has more air and transparency than the A21 but thats about it.

Right.  And I sold my $16k Class A mono blocks in favor of the NC400's.

[G Georgopoulos]

It all comes down to which class d, or which class b,there are good ones and bad ones in everything,class d may be small but uses intergrated circuits with lots of active devices inside these draw current at idle,compared to class b which is more efficient at idle and less complex,yes class d may be more efficient at output power but class b is close there,I personally dont like ICs because i have no control over whats going on inside there,also class d may be cheap compared to solid state and tubes and with more power o/p,that is the case also with class b ICs which are used in low end,with the rest we have hum with class d ultra sonics
you dont want to go there trust me!...

[DaveC113]

It's an exciting time when inexpensive class D amps are competition for expensive class A amps.

Those Crown amps also have crossovers and gain adjustments built in, I'm definitely going to try one for the lows paired with my SET amp in an active setup vs it (and other amps) powering the whole speaker with a passive xo... seems like a good alternative to using a plate amp for subwoofer duty, probably much better quality and a more flexible crossover vs a typical plate amp. They had great control over those big 18" subs.

[OzarkTom]

Crown XLS Drivecore 2000 Review

https://www.youtube.com/watch?v=b_F749Ngzc0

[OzarkTom]

Here is a full review of the Crown Amp.

http://www.arccinema.com/crown-xls-drivecore-amplifier-review/

It would be an interesting amp to try. These are selling on Ebay used for around $300, one went for less than $250. You won't lose a lot of money if you don't like the sound.

TI did have a hand in developing this Crown amp