Just read my posts more carefully. I am not saying that everything sounds the same. I have argued that amplifiers may sound differently for a few identifiable and avoidable reasons commonly ignored by audiophiles, and not for the magic reasons that they think. Amplifiers are clipping on input if there is a gain mismatch between the output of a source and the input of the amplifier, they may have a load dependent frequency response (largely a tube isssue) and they may be clipping on output because of insufficient power. Finally there is also an observational issue when sighted comparisons are made at different levels, and with too much time in between. The result has been too much agonizing over electronics and too much budget allocated to them. For the industry this is attractive because this is where the profit margins are (I will not even mention the cable folly).
I have also argued that the links of the chain at the interface between the mechanical and the electrical are far more flawed than people seem to think, and deserve more attention and a bigger slice of the budget (my argument is not that good audio is cheap). This is easily demonstrated by even the most basic and uncontroversial measurements. The explanation is simple, and nothing more than mainstream physics: these components have mass, and mass vibrates, is slow, and behaves in a nonlinear way. So microphones are imperfect, even the best ones (but this is out of our hands), and so is the vinyl link of the chain, and at the final end of the chain so are the speakers and their interaction with the room. For this simple reason I have abandoned vinyl years ago, and for the same reason I have bought what I think of as the best speakers money can buy (Quad electrostats, i.e. dipoles with less room interaction, and yes I listened to them), and applied room equalization to deal with the room modes generated by my sub (and yes I can easily hear the improvement).
In all its simplicity the argument is nothing more than that you do well to allocate your money to reduce the biggest errors in the reproduction chain. The strategy is a simple combination of science and engineering principles and economics: what is the marginal sonic utility of an extra $1000 spent on speakers compared to an extra $1000 spent on electronics? How does an improvement in electronics distortion from for example 0.002% to 0.001% compare to the sonic benefits of a reduction in speaker distortion from 2% to 1%? In the first case you go from 2.002% to 2.001%, in the latter from 2.002% to 1.002%. You can do a similar sum with frequency response, where good electronics can easily stay within 0.2 dB, but speakers have a very hard time staying with 2 dB. Their real world in-room response is even far worse. So I did start a discussion of room acoustics, but that has fizzled out for apparent lack of interest. So no, I will not claim that all gear sounds the same, or that no improvements are possible.
