My personal take on the psychology of separate vs. integrated electronics is, the design philosophy with over-spec'ed parts. When you look into the innards of an AV receiver vs. a separate power amp with identical (actual, third-party measured) power outputs, you always find that the separate amp has much bigger heatsinks, transformer(s) and power capacitors, etc. The question is whether, given that the measured power outputs are essentially identical, these bigger things really lead to a better sound quality. By definition, these bigger parts are over-spec’ed with respect to obtaining the given level of power output. While the little tech nerd in me would freely admit that the innards of the separate look infinitely more “beautiful” (and that may well lead to a better sound perceived by me), you can also argue that the integrated AV receiver has achieved the “art of just-enough design” at a higher level, producing the same power output and other specs within a much more demanding space (and often cost) requirements.
