Bandwidth Limitations Of Class D Amps??

At the NY Audio show recently, a few rooms had very high end class D amps that were superb. Other than a no-limit budget and ability to use a crane to move class A amps, my experience has been where top class D amps are just as good as some very expensive class a/b amps i have used.

they also work better if you want to go "digital" straight from DAC to amp with passive pre-amp

To echo Lapentas comments, I have reasons to believe that the stereotypical artifacts at the outer ends of the audible bandwitdh that were frequently associated with a number of older class D amps may not be necessarily reflected in recent designs based on much evolved power conversion modules, like the Ncore NC1200 by Hypex.

Case in point is the Merrill Veritas monoblock that I have just reviewed for Positive Feedback on issue No. 68:

http://positive-feedback.com/Issue68/merrill_audio.htm

Once the amps were properly broken in with 1,000 hours of active operations, I did not detect any musical bandwidth limitations, nor any stereotypical class D artifacts with Veritas.

Of course, there are other amps based on Ncore technology (such as Mola-mola Kaluga and ATSAH by Acoustic Imagery) , and other new class D modules other than the Ncore family (such as the Pascal modules). The examination of more examples of new class D amps should confirm or disprove my hypothesis of class D designs having now grown up into general musical adulthood.

G.

Class D amplifiers do require low pass filters to remove out of band power supply switching noise from passing to the speakers. This is also true of AB amplifiers leveraging high speed switching power supplies such as class H amplifiers (Emotiva and Outlaw for examples). Whether the filtering and related phase shifting is audible is a separate matter, likely depending on the listeners age and hearing loss that is inevitable with age and high sound pressure level damage to our hearing.