"The downside is that the Class D "sound" is not for everyone. I am particularly sensitive to the current Class D "lack of high frequency extension and air". Also, many of the Class D offerings use switching power supply. The ATI AT52x and AT54x models are one of the only nCore offerings that have a full linear power supply"
Hello auxinput,
I agree with you that the newer class D amps are extremely clean and clear sounding but I'm confused by what you mean when you state the downside is that the class D "sound" is not for everyone.
Confused because class D's distinguishing characteristic is that it's so neutral, like a straight wire with gain, that it has no "sound" of its own. If you don't like the "sound" when listening through a good class D amp, it just means you don't like the music it's playing. How can it have a "sound" when it's just taking the inputted signals, amplifying the volume faithfully without adding or subtracting anything which is verified by extremely low distortion measurements and then passing the boosted signals along to the speakers?
It's true that many class D amps use switching power supplies but I don't consider this a negative. All the class D amps I own (D-Sonic, ClassD Audio and Emerald Physics) have full linear power supplies with large toroidal transformers but I've listened to a lot of good class D amps using switching mode power supplies(SMPS) that perform very well and I'm not aware of any amps using them having any issues.
Your statement that you're "particularly sensitive to the current Class D "lack of high frequency extension and air" also confuses me. This is the first time I've heard of this affliction and I hope it's rare and not contagious. It's definitely and sincerely a shame your affliction prevents you from enjoying the excellent high frequency extension and air that I and so many others enjoy on a daily basis from our good class D amps. Your misfortune is a lesson to us all to never take our class D amps excellent full frequency range performance for granted, especially the airy and extended treble response.
I wish you only the best and hope you have a speedy and complete recovery.
Bless you,
Tim