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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
atmasphere's avatar
atmasphere
11,849 posts
 
Personally I have lost all interest in hard to drive speakers because I find their total cost of ownership just too high for little value.
+1 on that!

When you can connect headphones to the power supply of any amplifier and hear the audio signal, you may count on the fact that the power supply is contributing to IMD. This is a very audible form of distortion! It is for this reason that we have a separate power supply for our driver circuits as opposed to our output circuits.

IMO this should be the case in a class D amp too, and I think that should pan out as the input circuitry usually has very different requirements as opposed to the output section.
erik_squires
16,176 posts
 
@atmasphere

Hah!

A recent phrase has made it into the news, I'd like to co-opt as a statement I never want to make:

I am being dominated by my loudspeakers

Speakers, like friends and family, should be easy to get along with for me. Not the secret Mistress whose every whim should be catered to. That's what secret mistresses are for.

About headphones and power supplies:  True, I also think it's a way of checking for checking the effectiveness of power supply filtering. For instance, if you get a lot more HF in your supply, may mean you need less inductive filter/shunt caps. It is also a way of knowing when you have done enough, so if I ever worked in the field again, it is a technique I'd try to apply to see if I could learn about any power supplies I worked on.

Best,


E
erik_squires
16,176 posts
 
I guess what I'm saying is:

When I worked in circuit design we just threw a bunch of bypass caps of different types into the power supply without ever measuring their effectiveness or cost/benefits.

If I did this again, I'd take a more rigorous approach to every single power supply bypass cap. Spend money where needed as opposed to a shotgun approach.

Ahhhh, good times back then. :)

Best,


E
pcrhkr's avatar
pcrhkr
276 posts
 
Laugh if you want.  You can Spend $10,000 or you can spend a few thousand.  The Crown International Drive core 2 amps are cheap and have many turning in their esoteric amps. Lexicon uses Crown Drive Core technology.   Was compared against Emotiva and it did not come close to the power and sound.  These are going in home theaters. Google it yourself.  
I still run a Crown D150 Series II and it still sounds great.  Over 40 yrs old.   No, Not like a Levinson, but close to a MAC. which is good.  The Drive Core II are supposed to be better.
erik_squires
16,176 posts
 
Was compared against Emotiva and it did not come close to the power and sound.

Emotiva is a brand I had really high hopes for.

Best,

E
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