The Law of Accelerating Returns

Neither example provided in the article are correct in the context of marginal returns.. 

The first because the improvement is as a result of getting a dysfunctional system functional.  "unlocks the previously unrealized potential of your other components" 

Like replacing an incorrect rectifier tube or other similar build feature with the correct one.  Fixing a flat tyre on a car.  Everything will work better and as it was designed to.  This is shifting the returns curve upwards, not a movement on it.

The second is changing the technology which adds a characteristic that wasn't there previously.  Comparing two exact same cars but for the fact that one has a manual transmission and the other automatic.

Anyway, this is actually conceded - "Far from offering only incremental improvement"- but marginal analysis is only about increments.  So, does not apply by the author's own admission..

I think its probably not a good idea to use the marginal return concept to audio equipment.  It has a very narrow meaning, one that is exceptionally useful and informative in the correct context.

@asctim The author, Robert Harley, knows this. I know that because I once read something written by him that was both original and actually made sense.  He is not being honest.

However he also knows that his target audience either don’t know, don’t want to know, or don’t care, seeking some/any justification (however ridiculous) from an appeal to authority such as himself writing for the esteemed TAS.. See also what @8th-note says, above.

I’m highly skeptical that there’s any important signal information that is being mangled by the $400 DAC ... that would ruin the potential of the $10k integrated.