Competitive class D amp suggestions

@niodari 

Here's the measurement of the Technics SU-G700M2, which may not be exactly a class D amp, or a GaNFet amp, but which is something close.

As you'll see, some of the higher order harmonics are higher than one often sees, and normally you only want to see the second and third harmonics around that level.  John Atkinson commented:

"The fifth harmonic in both channels, the seventh harmonic in the left channel (blue trace), and the ninth harmonic in the right channel (red trace) were almost as high in level as the second and third harmonics. Although these harmonics are low in level, lying between –80dB (0.01%) and –70dB (0.03%), they could be audible at high listening levels in the region where the ear is most sensitive."

@twoleftears , I wonder how this integrated amp sounds with this speaker impedance correction feature. E.g., the distortion at higher order harmonics (the pick at 1k and the following ones at 2k etc) is considerably higher than that of the first, 2nd and  3rd order harmonics, they should be audible. Given that, it is really interesting how this is reflected on the SQ. 

The diagram is  "unusual" also because it shows  a big difference between the two channels where a little distortion is observed in the blue channel as there are only two blue picks.

For the Atma-sphere class D amp: Is a preamplifier necessary if only connecting a streamer/DAC to it? The streamer/DAC has it’s own volume control (if I want to enable it). Lumin S1.

Someone I came across (Ocean) mentioned this class D amp is definitely worth checking out.

Also, which preamplifiers are recommended for it (that have a remote)?

Other than heat and efficiency, what do you think are the pros/cons of moving to this amplifier from an 805 tube amp (Line Magnetic LM-805ia)?

@veerossi The designer of the Atma-Sphere GaN amp @atmasphere is on here regularly and hopefully he’ll chime in here with some very helpful suggestions and insights.  I believe he now uses his new GaN amp in his own system even over his very highly-regarded OTL tube amps so that may give you a clue, but hopefully Ralph can add more meat on the bones here for you. 

If you will decide to try Atma-Sphere class D amp, you may start to control it with the volume control of your DAC of course. Then you will see if you like the result and then think of a preamp (I have been using a passive preamp with class D). I think the amp is worth of trying and it comes with 15 days of trial (I ordered it just recently).