Class D Technology

Atmasphere 11-4-2016

A drunk ran a stop sign and T-boned my car, totaling it, back in July. I had a lower back injury that was really painful (bulging disk into my sciatic nerve); its only now healing to the point that I can dress and move in a normal fashion.

Oh, wow! Sorry to hear about this, Ralph. But of course I’m glad that it wasn’t even worse, and that you are progressing toward normalcy.

We practice pragmatism, not ideology.

No wonder we usually agree about things in the discussions here. In a past thread I recall describing myself as neither a subjectivist nor an objectivist when it comes to audio, but rather as a pragmatist with a technical background.

As far as the subject matter of the thread is concerned, I have no experience with class D, and nothing in particular to offer in the way of comments.

Kijanki, best wishes to your daughter as well.

Best regards,
-- Al

I also wish you a full recovery Ralph. Hope you are mostly pain free in short order from today. 

As far as I'm concerned the best Class D amps made today are the Mola Mola Kaluga Monoblocks, which I own. They have ZERO of the nasty sound behaviors people always seem to cry about when ever the topic of Class D technology comes up. It wouldn't surprise me if 99% of people who always crap on Class D base their opinions on hearing sub $2k examples of B&O ICE tech of yesteryear or even worse, are just parroting what they read elseware of other oblivious folks who fall into the previously mentioned 99%.

At the end of the day, you get what you pay for. Those mentioning issues with switching frequencies have no idea what they are talking about. Can you really tell me with a stright face that you can hear a 500Khz switching frequency and that you have a speaker that can reproduce such a sound? Come on people!

Class D amplifiers are good at delivering lots of clean power, that's true , but you listen to speakers driven by them . From my perspective the best sound has a seemingly limitless low level resolution and quickness where you can hear very far into the distance with what I call " the breath of life ".Everything sounds so real . High sensitivity loudspeakers do that the best and don't require tons of power . You choose your power amplifier to suit your loudspeakers , not the other way around . There are two new David Berning ZOTL amplifiers from Linear Tube Audio at 10 and 40 watts that offer enough power if you have the right speakers . I've only heard an older ZH270 and that's got the best sound I've yet heard . Would love to hear the newer designs.His designs are not class D , using tubes operating at radio frequencies , extracting the music signal from the carrier wave for dynamic , effortless sound .Reviews can be found .

I have a couple of Class D integrated amps: Peachtree Nova125 & NAD Master M2.  They are very different in quality IMO.

The Peachtree soundwise is pretty good.  Perhaps, it does have a little harshness some associate with Class D when compared to good Class A amps. However, I may have a unit specific problem with the DAC portion, which may be to blame for this (I will have to sort out with Peachtree). It also can get slightly congested with complex passages (bands & orchestras) at higher volumes. At it's price point, it does an excellent job. There would not be many/any Class A amps at this price, unless you bought some older, used ones.  It also does have a great feature set for digital inputs (only one analog).

The NAD M2 is a very, very, fine amplifier.  It is not a typical Class D amp, more of a powered DAC, using a relatively new technology.  It is very musical, which is not typical in Class D amps. It is absolutely dead silent when no signal is played, which makes it extremely dynamic. Very detailed, excellent bass control, mids are rich and authentic.  Makes high quality recordings sound exceptional. Given that it all you need is a source, the M2, and speakers, it is extraordinary value. (See glowing reviews in Stereophile and Absolute Sound that explain the technology)

Main drawback of the M2 is that it does not have a USB input, so a S/PDIF bridge is required in that case.  It does have both RCA & XLR analog inputs if required. The analog signals will undergo an A/D conversion because everything is digital in the amp, so purists may object. Personally, I don't notice any degradation when fed an analog signal. 

IN summary, the Peachtree is good value for the price, but (with my unit) may not satisfy those willing to spend big dollars on high-end Class A or Class A/B amps. The NAD M2 (costing several thousand more than the Nova125) is a good challenger for Class A & A/B amps costing quite substantially higher. Definitely worth auditioning. I believe it is no longer manufactured, but newer NAD products will use the technology.