Class D = Trash?


So, I'm on my second class D amp. The first one, a Teac AI-301DA which claimed to use an ICE module, was unlistenable trash. I burned it in for a few weeks, it just couldn't perform, so I sent it back. Following that, I tried the new Emotiva A-300 (class A/B). It was significantly better, but lacking in too many ways for my tastes. So I changed gears, got an 845 SET from China -- and it was an immediate and massive improvement.

So, before I went further down the SET road, I wanted to try a better class D product using a modern class D module. I settled on the D-Sonic M3-800S with the Pascal module and custom input stage. I read from reviews that these things like to have big cables, so I picked up an eBay 8 gauge power cable (Maze Audio, el-cheapo Oyaide copy plugs, braided 4-wire cable) to go along with it.

Mid-range GONE.
Soundstage depth CRUSHED.
Euphonics DISAPPEARED.

Yes, resolution went up. Driver control went up, allowing me to play compressed rock/pop and orchestra with the speakers being able to render it all. But enjoyment in the sound is basically gone. Using my best power cable (LessLoss Original) improved performance, but didn't fundamentally change the amp's nature. I ran back to my headphones (Focal Utopias) to detox my ear canals.

So, how long does a class D need to burn-in? I want to give it a fair shake before writing the technology off forever. 
madavid0
  I'm very interested in checking out your take on the first Atmasphere class D amp.
     Too early to share any insider details like modules chosen. type of power supply adopted, any customized components, target price and expected release date?  
We're doing our own circuit, so no modules, at this point we are using traditional power supplies.
Hi atmasphere,

     Proprietary power modules and supply?  Wow!  Very cool and very interesting.


Good luck,
   Tim
seanheis1
  I started a thread about it and it appears that the switching frequencies aren't currently high enough to avoid degrading the signal. If it was a simple break in issue, they would be broken in at the factory.

Don't give up on Class D though. When the switching frequencies improve, they will become the solid state amps of choice. Some folks don't hear what we hear and they are fortunate to enjoy these small and efficient power houses. More power to them.

Well said the day will come with much higher switching frequencies, as I also posted to Randy's question
randy-11I always thought the gentle filter slope was b/c steep "brick wall" filtering caused caused audible distortions...


It’s because a simple low order output filter can take the amps full power, but it’s effects reach down into the audio band and still leave some switching noise left overs, hence the need to take it up much higher as Technics did with far higher switching frequencies, so they can be effectively removed, without effecting the audio band.

These days when Stereophile tests a Class-d amp, they put on an external output filter, the Audio Precision’s AP0025 filter, which has a -50db rolloff after the audio band so the 1khz square waves look half decent without the switching noise embedded right across it, (good for sales) 10khz square wave still looks a mangled mess though, trouble is this AP filter can only take very low power, would be real nice to leave it in to listen to, but it would blow up in a micro second.

http://www.stereophile.com/content/class%C3%A9-sigma-2200i-integrated-amplifier-measurements#31YFAPfYVDGeowzZ.97  
And yes steeper filters as you said do have their own set of problems re sound, as ML found out with their No.53 monoblocks.

Cheers George 
Anybody here running or have auditioned Auralic Merak monoblocks?  Just purchased a couple and should be arriving today.  Moving to these from a Parasound Halo A23
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