Something I realized just now. Historic accuracy. To give an analogy consider the RIAA curve. It amplifies the high frequencies and attenuates the low ones. In

Something I realized just now. Historic accuracy. To give an analogy consider the RIAA curve. It amplifies the high frequencies and attenuates the low ones. In order to play this back correctly you have to do the reverse transform on playback. The recording device and the playing device both have expectations on each other, are designed with each other in mind. Now back to tube amps. People often say that tube amps add "warmth" right. So we can say that this warmth isn't actually there in the recording. It's an inaccuracy. But here's the thing, if everyone has a system that adds warmth, then mixes will take this into account. They will be mixed to reduce the warmth a little so it will sound just right when it's added back. The recording and the playback are designed with each other in mind.