Curious minds/ears want to know.
Yeah and just asked a book full of questions. Specifically, The Complete Guide to High End Audio by Robert Harley, which you definitely need to drop everything and buy right now.
Meantime here are a few brief answers to help you appreciate just how deep these waters are.
What you mean when you say (whether it’s a speaker or amp or preamp) it’s darker or warmer or softer or leans to the brighter side of neutral?
Wow only SIX completely different things all lumped together as if they are one!
A lot of audio terms are visual metaphors. Imagine you are in a room and looking around and there is just enough light to see everything, except for maybe in a few corners here and there. Replace corners with musical details and this is dark. So you turn up the lights and now you can see into the darkest corners but guess what? Now it is maybe a little too bright. Hurts your eyes. Or ears. These are all metaphors, remember?
Warmer is you go to a warm bulb instead of the daylight. The color balance shifts. Replace color with tone and now you got a handle on warm.
Neutral is a fantasy. Do you have any idea what neutral lighting is? All neutral means is whoever is using it, this is his idea of whatever is the midpoint between bright and dark, warm and analytical, etc. Neutral is no more objective than anything else. If you can just manage to learn this one thing you will be miles ahead of the game.
Are you talking about how ss compares to tubes to class D?
Now you are getting even more confusingly generalized. All these things can really only be intelligently compared in terms of how they actually sound. When you have done this a very, very long time you may be able to spot certain things by their sound signature alone. I heard one bit of silicon in a tube phono stage without knowing, just heard it. But you think it was fun writing all this so far? What I would have to write to explain just that one thing would be twice all this put together.
Analog to digital? How do you know what "neutral" is? How do you not know it’s actually in the recording?
More of the same. The really good one is how do you not know it's actually in the recording. That is the million dollar question. Right now you have no freaking clue. Here's the good part: right now neither do I! Listen to records, you start to think you know what is in the recording- until you get a really good copy of the same record and then realize what you were hearing was a pressing, not the actual recording. Now you are much closer to the actual recording, but still not there!
The really crazy part, it does no good to say you were there when the recording was made. All that means is you know what the instruments sounded like to you when you were in the room. That is not what they sounded like to the microphone you used in the room. You know what it sounded like when it was mixed down in the recording studio. Big deal! Are you saying we all have to go back in time to the recording studio now? Most of those are set up for what they are supposed to do, which is completely different than what we are doing, relaxing at home or whatever. Not sitting in front of a monster console looking through plate glass at a sound room.
Read the book. Learn the jargon. Master all the many subjects. Eventually you will be ready to come back to where you are right now: does it sound good? Can you afford it? Well, all righty then....