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My NAD 3020 D proves your Class D tropes are wrong

I have a desktop integrated, the NAD 3020D which I use with custom near field monitors. It is being fed by Roon via a Squeezebox Touch and coaxial digital.

It is 5 years old and it sounds great. None of the standard myths of bad Class D sound exist here. It may lack the tube like liquid midrange of my Luxman, or the warmth of my prior Parasound but no one in this forum could hear it and go "aha, Class D!!" by itself, except maybe by the absolute lack of noise even when 3’ away from the speakers.

I’m not going to argue that this is the greatest amp ever, or that it is even a standout desktop integrated. All I am saying is that the stories about how bad Class D is compared to linear amps have been outdated for ages.

Great to see new development with GaN based Class D amps, great to see Technics using DSP feed-forward designs to overcome minor limitations in impedance matching and Atmasphere’s work on reducing measurable distortion as well but OMG stop with the "Class D was awful until just now" threads as it ignores about 30 years of steady research and innovation.
erik_squires
speakermaster
738 posts
 
I can always hear class d amplification because it is so tonally off that it is like fingers scratching on a chalkboard to me.
erik_squires OP
16,056 posts
 
I can always hear class d amplification because it is so tonally off that it is like fingers scratching on a chalkboard to me

I doubt it.

bobauch
28 posts
 
   I don't own class D but I heard the first generation Rogue Sphinx in a pair of Maggie 1.7s a few years back. I couldn't believe I was listening to a 1200 dollar integrated. Detailed, powerful, and warm. Could have listened all day.
   Tube pre and Hypex if I remember correctly. 
     It will be on my audition list when my current Tube preamp/class AB separates need replacing. 
      
atmasphere's avatar
atmasphere
11,794 posts
 
I can always hear class d amplification because it is so tonally off that it is like fingers scratching on a chalkboard to me.
I just listened to a class D yesterday that was more focused and just as relaxed as a good tube amplifier. So I very much doubt this statement- it is trolling IMO.
Class D is used in most powered subs which is not to say it can produce high frequency well.
This probably depends on what is meant by 'very well'. I listened to two amps yesterday, one tube and one class D. They both have less than 1 degree of phase shift at 20KHz. The class D amp has over an order of magnitude less distortion than the tube amp at that frequency. But its primary distortion product is the 2nd harmonic, and enough that just like a tube amp the 2nd is able to mask the presence of the higher orders. So it sounds like a tube amp, although considerably more neutral owing to lower distortion overall and the ability to act like a nearly perfect voltage source.

But not all class D amps are like this. They have as much variance from model to model and brand to brand as you see in tube amps, which cover the gamut of SET, OTL, push pull triode, push pull pentode and so on.


The bottom line is you have to be careful about making blanket statements; in the world of class D as in almost any other topic blanket statement are so general as to be rendered false.
dave_b's avatar
dave_b
3,159 posts
 
Guess you can get used to anything after it’s been on long enough 🙃
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