2. amps-preamps
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The NAD M33 will cancel your complaints about Class D

There are many reasons to like one type of sound over another. Even among what are considered very good amplifiers there’s a broad range of tastes and preferences among audiophiles. Just ask a SET aficionado!

However, no class is more maligned, inappropriately, than Class D. To hear some regulars tell it, Class D sound will thin your blood, make your teeth fall out and ruin your enjoyment of just about everything because it sounds so (fill in a lot of tropes from the 1980’s here).

I’ve been listening to NAD’s prior collaboration with Bruno Putzy and I can tell with some confidence that none of those tired old tropes apply. For reasons related much more to tonal balance than anything else, I’m sticking with Class A/B in my main system, but with the introduction of the next gen Anthem AVR receivers and the NAD M33 I may be making the switch back to class D.

You don’t have to like the M33 or the Anthem’s but can we at least agree that it’s time to retire the old guard of reasons not to buy Class D? Lets lay those poor phantoms to rest.
erik_squires
dougeyjones's avatar
dougeyjones
163 posts
 
@erik_squires

The reason it’s a mediocre implementation would be obvious if you (or really anybody here) had bothered to read detailed measurements of other PuriFi implementations, which routinely reach -120db SINAD. The fact that NADs implementation is around -92db is pathetic by comparison. 

No axe to grind, just facts..
bigkidz
3,388 posts
 
Being in the business of building audio components, I wish that we could build one as good as our power amps but so far we have not been able to.  That being said, I find that systems that use class D amplification generally use another component in the system that seems to try to compensate for the Class D sound such as a tube preamp, etc.  Our main challenge is that we prefer tubes for sound they produce which is the dimension of the sound stage, decay of notes especially piano, etc.  I am not saying that there is no benefit at all, but our opinion is that we just do not prefer the sound in comparison.

Happy Listening. 
erik_squires OP
16,130 posts
 
The reason it’s a mediocre implementation would be obvious if you (or really anybody here) had bothered to read detailed measurements of other PuriFi implementations, which routinely reach -120db SINAD.


That's why it's nice to put supporting evidence or points in your post at the time you throw shade. It's far to easy to misinterpret any particular reason why you felt this was mediocre, or to be unable to seek out possible disagreements in the interpretation.

The actual specifications  are:

  • Signal-to-Noise ratio
  • >98 dB (A-weighted, ref. 1 W out in 8 ohms)
    >120 dB (A-weighted, ref. 200 W out in 8 ohms)

    • So, you are incorrect, by 6 dB ( a lot) at 1 watt and please be sure you are measuring apples to apples and using the correct power spec for the S/N.  If not specified, assume it's at full power.

    I strongly suspect your 120 dB comparison was at full power.  Let me know if you find a reference to data that shows my interpretations are mistaken.



    Best,

    Erik
    Post removed 
    dougeyjones's avatar
    dougeyjones
    163 posts
     
    Erik, my reply was deleted by mods because they’ve figured out that any conversation that runs counter to the prevailing orthodoxies here is bad for business.


    My stated SINAD numbers were taken from the full ASR M33 write up, which I linked above. I was comparing unweighted measurements versus the PuriFi reference design which has already been exhaustively covered by ASR. Mid 90’s SINAD is about 25db more noise than the reference design, so not anything to write home about. 

    Think I’m done posting here, it’s not fun being moderated over nothing. 
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