Audio Research DS 450 amp......thoughts

Palewin
Since it is my experience I can make a statement like that.
I have heard most of the "high-end" class D amps around.
Spectron, Rowland, Nuforce, Bel Canto, Embla etc, etc and none of them have been able to create a solid soundstage that I expect from a truly "high-end" amplifier.
Sooner or later we will see switching frequencies that allow for output filters at 200 Khz or higher, but until that happends the class D technology will be inferior to traditional amplifier technology.
...and please remember, that is MY experience so far so please don't tell me what I can't say or not...

If you have a different opinion please express it.
Perhaps you can mention a class D amplifier that can compete with a Audio Research VT-200 regarding soundstage and honesty to the recorded music ?
Because that was the original question that started this small debate...

Let's lower the temperature of this discussion a bit. My objection was simply that if an entire amplifier technology is inferior, I don't understand why a fairly large number of respected manufacturers keep pursuing it.

My own experience is a lot lower-priced than many of yours. Over the years I've owned Quad 303, 405, BGW 250, ARC D90B, and now an ARC 150.2 amplifier. None come anywhere close in price to an $11K (when it was discontinued) ARC VT200. So I have no opinion on how any of the amps I've owned compare to a VT200. If I can make a gross generality of my own, I would expect an $11K amp to outperform any of the roughly $3K amps I've owned. That has nothing to do with technology, just my belief that in general you get what you pay for. From my own experience, all I can say is that I feel the 150.2 drives my Maggie 1.6s better than the D90B did, and paired with an LS17, I enjoy the music. So I would say my own class D experience is positive, within the price parameters of my own equipment.

The original question asked for opinions on the DS450 (the VT200 entered the thread a bit later), and since I haven't heard it, I stayed out of the discussion until the general condemnation of class D came up. Obviously, since I own and enjoy a class D amp, I have a desire to defend the technology to some degree. What I find somewhat contradictory is that a number of reviewers (regardless of whether one likes reviews or not) have been positive about at least some class D amps. I believe the Nuforce amps have been on Stereophile's class A (now that's confusing!) components list, in Soundstage's review of the ARC 150.2 the reviewer specifically recommended it for Maggies, and in TAS, Tom Martin actually purchased his review 300.2. I haven't seen any reviews of the DS450 or DS225; IIRC the review of the DSi200 was positive. Now none of this is definitive in any way, but it suggests that there are at least some who aren't negative about all class D amplifiers.

As a quick aside, my understanding is that Levinson's #53 is a switching amp, and I don't know of any class for switching amplifiers other than "D." I would suggest (without any factual support) that it is precisely the overall negative connotation that some have for class D which is why Levinson argues that their amps are not class D. That may also be why ARC called their 150.2 and 300.2 amps "class T" (after Tripath, the manufacturer of the chip) rather than class D, and I'm not sure what they are calling their DSx series.

Palewin
A lot of reviewers get blended by the emperor's new cloths.
For example:
PS Audio HCA was one of the first class D amps that reached a class A rating at Stereophile.
http://www.stereophile.com/solidpoweramps/729/
The words was "tubelike" "revolutionary" the best of the best and had to be considered regardsless of price.
Today reality have catch up, and if you even can sell one of these amplifiers you will only get a few hundred dollars.
I used to own one, and soon discovered that it didn't sound very well, so it was removed from my home after 4 months.

I used to own a 150.2 too.
The reason for buying it was for driving a pair of Magnepan 3.5R in my TV system, and the only reason for selecting 150.2 was for the posibility to keep it on permanently without the power consumption and because I really like ARC as a company.
It was paired with ARC LS12 as a linestage (lovelly sound from this little linestage).
I soon replaced the 150.2 with a Restek Tensor and the improvment was enormous.
The soundstage quadrupled in size and suddenly all complex acoustic instruments was rendered with full size and sounded as the real music event.
So sorry if I recommend that you try a different power amp that isn't a class D amp.

Sorry for Tom Martins decision to select 300.2 unless he use it for bass only as I do with my 300.2
...and of course I have tried my 300.2 for full range operation.
Does it sound good and cast a high-end soundstage?
I'm sorry but it doesn't.
It's dynamic and sound powerful, but it can't let the music through in a unharmed way.

From my point of view switching technology is best kept for powersupply service and leave the amplifing circiutry to traditional amplifing technology.
Two companies that have come to the same conclusion are Linn and Halcro.
Both have got some nice reviews from the press too.

But I expect class D technology to keep getting better and better and eventually it can compete with traditional amplifiers.
I will keep listening to them.
This is what I have found until today...

Do you remember the seventies when tube amplification almost died out because of the new revolutionary transistor technology ?
Today we know better...

I don't think we will see a similar evolution with class D amplifiers, but be aware of the problems with the basic technology that class D amplifiers are built on.
The industry will eventually solve them, but from my point of view it will take some years from now.

Palewin

Regarding the "T" class that ARC state it depends on the fact that it is a variation of class D amlifier with a variable switching frequency, but make no mistake, it's still composed of a comparator that compare a triangular wave with the signal and produce a PWM signal to drive the switching output transistors.
Just to vary the triangular wave switching frequency according to the demand of power will not make it a none class D amplifier.

There are some other versions of switching amplifier technologies (E/F/G/H), and there have been some examples of class G and H in the market. Usually for our portable audio devices.
E and F is for high frequencies and not suitable for audio.

Please read more here if you want:
http://en.wikipedia.org/wiki/Electronic_amplifier

There is one instrument that can disprove all the theory's in the world,and that is the Human Ear!