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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
guidocorona
4,298 posts
 

Fascinating... Looks like my last post has dematerialized. I was not aware that what I write is so controversial. Oh well...


To Charles, Mola Mola is a very fine amp, but it might not constitute the "last word" in the application of NCore technology to an amp. In the current Rowland lineup, for example, I have found some amps that I prefer over Mola Mola, and at least one that I like less. E.g. My M925 monos and the M825 stereo are in the top range of my preferred amps, together with Solution and ARC reference amplifiers. Yes, I do prefer them to Mola Mola.


When I listened to Mola Mola, the amp was not fully broken in, so it exhibited some excesses in transient response, and some transient behavior that might have been traces of intermodulation.... Difficult to say if the issues are inherent to the device, or they were a product of incomplete break-in.


Hence, I currently prefer the Pascal M-Pro2-based Rowland Continuum S2 over Mola Mola.... An integrated that I find infinitely graceful.


On the other hand, the Rowland M525 mono based on Pascal S-Pro2 might not be as subtle as Mola Mola.


Note that I have not listened yet to the Rowland M125 bridgeable amp, nor to the Daemon super-integrated... I have heard wonderful things about them, but have no direct experience.


Saluti,

 

mapman's avatar
mapman
22,373 posts
 
I think a special niche for Class D, where it offers undeniable unique benefits that support better sound quality, is as a more practical  alternative to traditional big heavy expensive monster amps when lots of power and current is beneficial to drive certain speakers to their max.

That is what led to my foray into Class D. I got the 500 w/ch Bel canto ref1000m amps as my all out assault to drive my big OHm F5s to the max and that has worked out in spades.

There are other practical options in most other cases.

For example, the Bel Canto C5i 60 w/ch integrated I use on my smaller system does it all and the sound is the cats meow (very hard to fault) in that app as well, but there are many amps of many designs in the same power class that can work out just fine there as well. So not as clear a choice there. The C5i does have the other advantages of value (especially used), compact size and manageability, and versatility (includes dac and phone in a package smaller than a shoe box which also has the form factor to fit easily into the rack where it must live).

I would not expect someone who finds set sound to be most appealing to be allured by a Class D amp. It might approach the sound of a set if done a certain way but there is no value in replacing a good SET system with Class D if the SET checks all ones boxes. If volume/macrodynamics is of concern given SET amps low power output the solution is more efficient speakers, not a more efficient amp. A change in amp will likely trigger or necessitate a change in speakers and other things as well, a major ripple effect.

I would see merit perhaps in maintaining two unqiue systems with unique strengths and technical approaches, one SET and one CLass D or similar. That’s an experiment I have on my bucket list still. But frankly the C5i has worked out great and pushed that off for now a bit until such time I have ability or desire to pursue perhaps a third system just to see.
grannyring's avatar
grannyring
6,517 posts
 

Mapman, I looked into Class D as I can no longer deal with heavy amps. (back issues) My all in one Lyngdorf weights about 20 pounds. I still have one tube amp that I use on occasion with the Lyngdorf. When my tube amp is being used I use the  pre, dac and room correction portion of my Lyngdorf as the front end. I can compare the Lyngdorf  amplification to my tube amp. The Lyngdorf is better overall and does not impart a particular sound that I would define as SS, PP tube, or SET tube. It just sounds right.

I just enjoy working on point to point wired tube gear and like the look and feel of tube gear. My love for tube gear is probably more emotional and tactile than sonically based. At least this is now true based on the wonderful sound quality of the Lyngdorf.

The neat thing is the Lyngdorf's room correction passes the ideal signal through my tube amp making it perform better than it would normally.

Like you mentioned, I am now able to enjoy Class H and tube amplification in the same room, with the same gear,  when I choose. Not two systems, but two options which is fun.

seanheis1 OP
629 posts
 
Does anybody know what causes the dead silences in songs that is a characteristic of Class D? Is it the output filter or dead time? I really noticed this with my Ice Module and couldn’t figure out if the amp wasn’t allowing for the music to decay or if it was something else causing the inky blackness.
atmasphere's avatar
atmasphere
11,874 posts
 
Its not 'dead time'! I would not expect the filter to have anything to do with it either.


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