Ralph,
So, you are an expert on damping? You spent hundreds of hours with various damping materials and used them everywhere and you know which damping materials are linear and which are not and where to use it and where not to use it? I doubt it. I am not an expert....but I have spend countless hours damping things with various materials.....and all class D amps are sensitive to damping......and yes, you can overdamp. This is not a theory of mine. This is based on truth.....truth equals direct experience. I try lots of things and I listen. What did you try? Do you have great feet underneath your amps? Do you have them sitting on tricked out shelving and isolation platforms? I doubt it.
When my friend damped the heatsinks on his Parasound amps he first put too much on and it made the amps sound dead......but one....one inch wide strip down the middle of each heatsink improved the sound over not damping.....very serioulsy. Yes, you can overdamp. And this EAR material is the most linear I have found.....but you still have to be careful what you damp and how much you damp.....all determined by the EAR.....our best tool.
Some say "nothing makes a difference"......others say..."only what I say (usually by theory) makes a difference".......and others KNOW that "everything makes a difference".......and those are the people who open mindedly listen to lots and lots of things.....and the more they listen the more they know they know NOTHING.....because it is impossible to try everything. The game is infinite.
Here is another tidbit of info. The Pascal class D modules are very good by themselves. D-Sonic makes nice ones. However, Aavik uses these modules in their expnsive class D integrated amps but they add their "tesla coils". These are a filter that works better than normal inductors and caps (like what Ralph has on the input of his amps). The more expensive Aavik amps use the same Pascal modules and produces sound better......mainly because they have more of these "tesla coils". Please go to their site and read the info about these coils (passive and active versions). This is why an inverter is so important. You get rid of tons of noise and distortion right at the source.....the terrible AC line......you eliminate a lot of noise right there.....you cannot have enough noise reduction (determined by listening). Noise and distortion are the same thing.....noise is distortion......distortion is noise. When you have better footers and stands you have less noise.....when you raise your speaker cables off the floor you have less noise......it is infinite. It is not a theory......it is hearable.....it is truth.....truth is what you EXPERIENCE.
May you experience the Truth of your being......your beauty....your love.....your joy. It is always present.....with every breath. Breath it in....feel it...breath it out and bless others. Have a great every moment!