My NAD 3020 D proves your Class D tropes are wrong

Can someone direct me to a good source to get a better understanding of the differences in Class A, A/B, & D amplifiers? I thank you in advance.

Here you go, @allenf1963

https://en.wikipedia.org/wiki/Power_amplifier_classes

@jwl244,
"@decooney I wish I could say I put a ton of time in. I may have listened here and there for less than 20 hours total in a few weeks. I did not switch speakers in or out."

Good to know. Barely scratching the surface of end-game potential, possibly. I won’t name the company, yet the owner of a different Co started wondering why they were getting more returns than ever anticipated on a solid sounding product. After some in-depth internal investigation ,something very telling surfaced for this Co. They instituted a (3x) much longer pre sale/shipping burn-in process to these particular class-D products and components. The customer returns dropped radically after this process was introduced. Then they tell the customer to give it another 100-200hrs for the final 5%. Not all, but some higher-end gear benefits from longer burn in cycles, finally reaching a set point, optimum specs, bias, and maybe the type of sound we all look for. Its definitely worth giving a try in the future, fwiw. Good luck.

Going along with that, there is something about some Class D that requires DAYS to warm up.  Even after being used and on for months my ICEPower monoblocks sound like garbage after being left off for a weekend.

I have not run a binary search pattern to correlate time off vs. sound quality, but there have been about half a dozen other encounters with other audiophiles who have had this phenomenon. 

@decooney yes I've heard similar reports. I believe PS Audio burns in certain products before shipping as well. To be honest I'm not a huge proponent of burning in although your example would give credence to it. Not trying to get into a burn in or not thread.. I am curious in your opinion and others in this forum...

Is one possible reason we lean away from class D because of its distortion profile or lack thereof? My understanding with the best class D and purifi products distortion is really low. Maybe I'm wrong. On the end of the spectrum class A and AB products introduction more distortion but in a "good way" and this creates that "tube" sound so many audiophiles gravitate to. I'm not saying there's no class a or ab products without low distortion. I'm saying the distortion introduced by those products might be more pleasing to our ears. This is the departure away from measurements and numbers and just what we like to hear. Maybe there's more of the 2nd order harmonics if you subscribe to that. Class D might be too clean after all making those products sound clinical and unexciting. 

I doubt anyone on here has heard the new Legacy Amps. 1000 watts per in Mono blocks, 600 per in 7 channel. I have each powering up my Legacy speakers .. I came from ATI Signature series . It was their premier model. These Legacy V series class D's are better ...and cleaner, and quieter, and a lot cooler ...