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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
seanheis1
627 posts
 
Very interesting point about switching frequencies… What is the acceptable switching friequency range is targeted by the pundits?
Below is a quote from George from the Class D technology thread. 

The day will come when Class D will compete and very well be better than any linear amps tube,s/s, class A, AB or whatever, BUT!!

 Class D needs much higher switching frequency (needs to be at least 5 x higher) technology isn't there yet but in the future it will come, only then will ClassD become a contender. Till then good for budget hifi and subwoofer/bass amps.

Technics has progress the Class D race and developed 2 x the present switching frequency with their own made components, in this amp but it’s very expensive $20-30k
https://forum.audiogon.com/posts/1334662?highlight=Technics

When the switching frequency is 3mhz or better, then it can be called hi-end, and will own it myself, then my linear heavy boat anchors will be sold or become door stops.



Cheers George
seanheis1
627 posts
 

Guido, is there any scientific explanation behind these Class D break in numbers? I can see speakers maybe needing a bit of time to break in....but transistors???

Given that break-in of a class D power amp ranges from 600 hours to approximately 1500, asking a manufacturer to exercise the device for upwards of a couple of months before shipping it to a dealer may be woefully unrealistic… Of course, everything is possible…. For a commensurate list price uplift.

 

G.



mountainsong's avatar
mountainsong
422 posts
 
New Marantz PM10 class D. Excellent.
aberyclark
1,355 posts
 
IMO, if the component "ain't happening" new out of the box, then breaking in will only result in minor improvements. The sonic character is either there or it isn't. You may talk yourself into liking it, however it probably won't win you over if you are truly honest with yourself. 

georgehifi's avatar
georgehifi
10,312 posts
 
seanheis196 posts04-01-2017 9:36am Very interesting point about switching frequencies… What is the acceptable switching friequency range is targeted by the pundits?
Below is a quote from George from the Class D technology thread.

The day will come when Class D will compete and very well be better than any linear amps tube,s/s, class A, AB or whatever, BUT!!

Class D needs much higher switching frequency (needs to be at least 5 x higher) technology isn’t there yet but in the future it will come, only then will ClassD become a contender. Till then good for budget hifi and subwoofer/bass amps.

Technics has progress the Class D race and developed 2 x the present switching frequency with their own made components, in this amp but it’s very expensive $20-30k
https://forum.audiogon.com/posts/1334662?highlight=Technics

When the switching frequency is 3mhz or better, then it can be called hi-end, and will own it myself, then my linear heavy boat anchors will be sold or become door stops.



Cheers George

Yes it actually, the filter that’s needed to rid that switching frequency and all it’s artifacts that does the damage also to the audio band at the moment.
( switching frequency artifacts left over are the buzz-saw ringing that one sees on test 1khz square waves)
http://www.stereophile.com/images/archivesart/805CIAfig2.jpg
(And the filter also causes phase shifts in the 5khz to 20khz of the audio band)

If the switching frequency were higher, then the filter can do it’s job without effecting the audio band, and get rid of all ringing that’s left over on those square wave tests.

So I wait in hope for technology to advance so the switching frequency can be up around 5mhz.
Technics in the above link have got it up, with special transistors to 3hmz they are showing the way, but that amp costs $20-30K and is special order only.

Cheers George
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