Class D Technology

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.

In my personal opinion, I think the very best sounding Class D amp out there right now are the Classe Sigma Mono's.  However, I still think a  Class A,  a Class A/AB,  or  a  Class AB amp will still at this point in time beat sound wise any Class D amp, but I'm talking Class A amps of the high end order vs Class D amp also built by a high end manufacturer.  Of course a high end manufacturer's high end Class D amp will beat a mid-Fi companies Class AB amp. I don't think any mid-Fi or low-fi company builds any pure Class A amp's as I'm sure all of us already knows that.

I own NuForce mono block class D amps.  They were cited by Absolute Sound as "amp of the year" several years ago. Combined with a tube preamplifier and old Dalquist DQ 20 speakers, the sound is remarkable.  I listen mostly to Classical music and find the rendering more lifelike than with any other amp I've owned.