Now I'm confused. I was told and read posts that all amps/preamps sound the same since they only increase the signal's volume. If the file is resampled from 24/192 to 16/44 I wouldn't hear the difference.
Unless it's unusually bad resampling you wouldn't.
What I'm saying is that bits are bits - and that's a mathematical fact. A WAV and that same WAV compressed to FLAC cannot sound different because they have exactly the same contents, in the same way that both 2 and 4 cannot help but be divisible by 2. It's how math works.
Once those bits become analog signals, things become much more variable - all the audible differences you describe, if they exist at all, are very likely created in the analog stages.
Good amps don't color the sound -
not all amps are good,
not all amps or preamps output at the same levels, etc.
You can test this all - if you hear a difference, and it's not psychoacoustic, then you can isolate and measure it.
When you do that, you will find the difference doesn't lie in the bits, it will lie somewhere in your analog stage, if it exists at all - unless something very unusual is happening in software and we're no longer getting bit-perfect output to the DAC.