Class D Technology


So I get the obvious strengths of Class D. Efficiency, power output & running cool which allows for small form factors. I also understand the weaknesses somewhat. 1. Non-linear & lots of distortion that needs to be cleaned up with an output filter. 
So my question is, if it weren't for efficiency & power, would there be any reason to own a Class D amp? Do they beat Class A in any other categories that count for sound quality?  
seanheis1

Guido, in your posts you have indicated the Merrill Veritas are among the Class D amplifiers you enjoyed listening to and that do not display, "any displeasing high frequency artifacts or limitations."  

I owned the Acoustic Imagery Atsahs, which should be a close sonic twin to the Veritas.  Unfortunately, I cannot confirm the differences between the two since Merrill does not condone opening their amplifier casework and looking inside and I can find no posted pictures of the insides of a Veritas amplifier.  Based on my review of online information, the differences between the Veritas and Atsah amplifiers include, hook-up wire and binding posts, individually milled spaces inside the Veritas chassis - although both use solid milled aluminum casework, soldered wire connections (Veritas), and the use of the Hypex input board (Atsah).  I would not expect these differences to substantially, or possibly even noticeably, affect sonics as perhaps would items such as a linear power supply, input buffer or input transformers.  One listener over at Whatsbestforum who tried both amps (and ended up buying Mola Molas) posted this;

"They are sonic siblings. It would be silly to argue otherwise. The basic designs are the same. They both use the same unmodified NCORE SMPS and NCORE 1200 module from Hypex. Sonically, I would give the nod to the Veritas. They are a little more resolving, but not by much and I don't have them side-by-side. So, if an Atsah owner calls me out on this, I won't fight back."

So, proceeding on the assumption that by owning the Atsahs for over a year, I have a mostly reliable understanding of how the unmodified SMPS1200 and NC1200 modules sound, whether in the Veritas or Atsahs, then my question to you is, would you describe what you hear differently between the Veritas and the Rowland M925 amps that have earned the M925s a permanent place in your system? - Thanks

(reduced price,electricity consumption,heat, size and weight)

Take the "green" thing out of it  has nothing to do with sound quality.

Audiopiles have never been "green" let face it those that keep on about the "green thing"  are a bit hypocritical. It's a wonder we aren't dead just listening to our "non green" audio.
I bet the greenies that spruik the "class d green thing" ignore the rest of the toxic waste dump inside their other audio equipment.
 
the energy tube and s/s use
before vinyl it was bakalite
then vinyl
Boron cantilevers
Nickle inside tubes
Toxic fluid in capacitors
Beryllium dome drivers
CD's
ect ect  ect  

Cheers George
Don’t listen to the negative propaganda especially from just one or two who repeat the same thing over and over. Just try them for yourselves if interested and see. 

Myself, I’ve had way less trouble finding top notch sounding Class D amps than others. 
Mapman, I'm glad that you enjoy your Ice Modules. The KEF LS50 was just released in an active version. The woofer is powered by Class D and the tweeter is powered by Class AB. Does this mean that there is a problem with Class D higher frequencies to some ears...or is it just an issue with procurement budget and not being able to purchase the better Class D modules? I don't have those answers but it is food for thought. 

Hi Mitch2, my PFO article on Veritas details all the technical information that I have gathered on Veritas, based on conversation with Merrill, and by reading the publicly available technical literature on the amp. See:


http://positive-feedback.com/Issue68/merrill_audio.htm 


Unfortunately, I have not heard the ATSAH, so I really cannot comment on internal differences, nor sonic differences.


In itself, Merrill Veritas is exceptional value for its $12K list price. In a more traditional SS design, At the time of my review a couple years ago, I would have expected such sound to be more in the capabilities of an excellent amp in the lower $20K range.


Although there are obvious commonalities between the behavior of M925 and Veritas, there are quantitative and qualitative audible differences, which are however less than the price difference would suggest.... Famous laws of diminishing returns that audiophiles are acquiented to *grins!*


Thus, were I to ignore any budget considerations, my preference would comfortably go to M925 for the following parameters: 


* Power reserve

* authority.

* Macro and micro dynamics.

* Harmonic exposure.

* Linearity.

* Frequency extension.

Transparency.

* Sweetness and complexity of treble.

* stage size and concreteness.

* Imaging concreteness.

* Aliveness of "black" background... Also called the sound of the silence between the notes... Or the reproduction of ultra-low level information.

* Immunity to electronic background noise.

*  Immunity to intermodulation artifacts in the treble region.


Yet again.... let us Keep things into perspective.... the rowland M925 was engineered with a sophistication commensurate with its pricepoint just shy of $60K, several times the price of Veritas.

 

Saluti, Guido





 

To me the fact that that a number of forums are now being devoted to class D amps indicates the importance and growth of this tech.
I have 3 different class D amps all at different levels of sound quality. with the new Bel-Canto Ref 600 mono's as the newest and most complete.
They really  respond to tuning with power cords! They are green, run cool, but perhaps as important they are much easer to move around. Are they the last word in amps? not yet.. but getting much better day by day.