"not about the $, its about what does it take to engineer a machine that becomes invisible

I disagree. The problem is all system's are compromised to some extent. People either avoid systems or speakers that have a compromise they really do not like or are attracted to systems or speakers that do something they like or a combination of the two. However IMHE when confronted with a system that has relatively few compromises and particularly images well and is devoid of sibilance, everyone will drop their jaws and universally agree it is one of the best systems they have ever heard if not the very best. The very best systems, with the right recording can fool you into thinking a violin is playing in your living room or even a piano. Very few systems can do that. So, we are forced into accepting certain degrees of inaccuracy and the audio industry gives you a choice of inaccuracies on purpose. This is particularly true of speakers. 
The differences between the excellent amplifiers we now have are relatively minor as long as they match up with the speaker well. 

Notice in this video that price, in these people's minds is the primary indicator of quality. If it costs more it must be better. This is not the reality I live in. I have heard $100,000 systems that stomp on $300,000 systems. It also takes engineering to make speakers disappear and clever engineering at that. At home you (or someone else) have to engineer your system and room to produce the desired results. You can't just throw equipment into a room and expect it to work well.

Nothing gets more in the way of the music than the room. 

transistors won't function correctly unless they produce a noise characteristic that is wholly inseparable from the signal itself.

Where that's just one part of the problems at hand regarding the integration of what we call electricity --with elemental and alloy atomic lattice systems.

"I think there is a burn in. Thy sounded better."
"Maybe you got better weed."

I completely understand why many listeners prefer and seek out the rich harmonic distortion of tube amps and similar gear that doesn’t perform so well on a test bench.

The problem here is that most solid state amps make harmonic distortion too- but being higher orders, is interpreted by the ear as brightness and harshness.


This is why tubes are still around. But the real problem isn't transistors so much as its a  lack of enough feedback. Feedback is on a sort of bell curve- with 17.5dB of feedback being right in the middle of where you don't want to be! You need about 35dB of feedback to really get rid of not only the innate distortion of the circuit but also to knock down the distortion caused by the application of feedback itself. The semiconductors needed to do that really didn't exist in the 1970s and 1980s. Also the **will** to design such an amp has been a bit lacking as well.


You know you have a problem if the distortion measured at 100Hz isn't the same at 1KHz and 10KHz. Often it isn't because the amplifier under test lacks the Gain Bandwidth Product to stay linear- so the distortion increases with frequency as a result. Essentially the feedback is decreasing with frequency. This is why the industry usually only does its harmonic distortion measurement at 100Hz...


The other part of the distortion signature that might be more important is that there be enough of the 2nd and 3rd harmonic (both treated by the ear the same way, which is to say that the ear is insensitive to them) to mask the presence of the higher orders. This might actually be more important than how much distortion is present overall, although its best to keep it low as it can mask detail. If the higher orders are masked the amp will sound smooth (which is why tube amps often sound smooth despite having higher distortion than solid state amps).