Any experience with Class D amps and impressions?

Discussion in 'New Gear - Performance' started by kurtgo, Mar 14, 2018.

  1. guscjr

    guscjr Active Member

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    Hope some AK member grabbed the Classe Sigma Amp2 I saw at a local pawn shop a week or so back. Knew the quality of the brand, no idea about the model. Looked like new. Specs on back panel were cryptic. Did a bit research on it. Wow...! Asking price: $550. Kicked myself in the rear today as of course, it's gone. Would have loved to try it here as a stereo amp with my Kappa 7s.
     

     

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  2. Poultrygeist

    Poultrygeist Lunatic Member

    Class D of a few years ago is not the same as it is today. The technology is advancing so rapidly that you don't want to get stuck with an older implementation.
     
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  3. Soundphile

    Soundphile Active Member

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    Location:
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    Anyone tried a Class D amp running GaN outputs? I haven't heard it but apparently, its a significant improvement in audio quality, extremely low background noise, wide frequency range with very low dropouts, etc.
     
  4. Poultrygeist

    Poultrygeist Lunatic Member

    Are they widely available? I only found an evaluation board for $1300+. If GaN is as good as they say I'll wait on the affordable Chinese clones.
     
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  5. Soundphile

    Soundphile Active Member

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    I think GaN Class D amps are not widely available as yet. I too am awaiting the affordable clones. It looks to be an interesting development.
     
  6. Poultrygeist

    Poultrygeist Lunatic Member

    Let us know when you kind a clone.
     

     

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  7. E-Stat

    E-Stat AK Subscriber Subscriber

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    Their biggest challenge is the significant amount of ultrasonic switching noise present in the signal. Do those outputs allow for higher frequency switching?
     
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  8. fredgarvin

    fredgarvin AK Subscriber Subscriber

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    Right now the class D amps being built using the new IceEdge 1200as2 modules, such as Mivera and Nord, have captured a lot of attention. People are selling their high priced AB amps, Pass et al after hearing these.

    A new one that looks very interesting from Nuprime-

    A new input stage with a 1MΩ input impedance.

    700KHz high-speed switching Class-D module

    http://nuprimeaudio.com/product/evolution-one/?v=7516fd43adaa
     
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  9. Poultrygeist

    Poultrygeist Lunatic Member

    and we'll be able to afford them when the Chinese introduce their clones
     
  10. fredgarvin

    fredgarvin AK Subscriber Subscriber

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    I think you'll be waiting a long time for that.
     
  11. Poultrygeist

    Poultrygeist Lunatic Member

    We'll see. With the Texas Instrument TPA's it only took a few months.
     

     

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  12. Pio1980

    Pio1980 AK Member Subscriber

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    But using oem TI production, afaik.
     
  13. theophile

    theophile Pheasant Plucker. Subscriber

    Is that because TI is making them in China and thus Chinese clones are actually 'the real thing' off the assembly line 'the real thing' was made on?
     
  14. mkane

    mkane AK Subscriber Subscriber

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  15. Pio1980

    Pio1980 AK Member Subscriber

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  16. 45rpmspinner

    45rpmspinner Well-Known Member

    TPA 3110/6/8 were, and still are, dirt cheap. Especially in bulk.
    One of the reasons you don't see too many Chinese TPA 32XX builds is because the chips cost 3-4-5 times as much, depending on what you're comparing.

    Btw...looks to me like GaN output units are currently only used in industrial/military applications.
     

     

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  17. Poultrygeist

    Poultrygeist Lunatic Member

    Another reason you won't see the proliferation of the TPA 32xx amps ( compared to the TPA 31xx ) is due to the higher cost of their more powerful psu's.
     
  18. Pio1980

    Pio1980 AK Member Subscriber

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    The TPA31## chips yield the '''goldilocks" bracket of Class 'D' audio for experimenters and the curious, I'm very impressed with the SQ value that shows the promise of this technology.
     
    Last edited: Aug 12, 2018
  19. Soundphile

    Soundphile Active Member

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    Location:
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    Class D Amps and Switch Mode Power Supplies work in almost a similar manner. Both can only function by employing very high ultrasonic frequencies ... that introduce noise. Has anyone tried to power a Cass D amp with Linear Power Supply? I figure that with this setup, the power supply part will not have any ultrasonic noise (effectively, half of the noise will not even be generated at all). The inductors after the output stage only needs to filter out a much lower "quantity" of ultrasonic noise, resulting in a cleaner output. The downside is that the larger size of the Linear Power Supply would just take up more space. Any thoughts?
    From this point onwards, I tend to believe that Cass D amps will develop rapidly to a stage where they would eventually trounce the CLass AB or Class A amps in all aspects of audio quality. Clones from the East would also become available rather rapidly. It would appear that we are sitting on the cusp of a Class D invasion !!!
     
  20. Pio1980

    Pio1980 AK Member Subscriber

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    Several examples of heavy iron powered Class 'D' switchmode amps have existed and do exist. They have generally been good to excellent. I do expect great results as it matures.
     

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