You just stated above that any modern op amp has no sound (will not change the sound).
The above statement is false. Here is what I actually said:
Not to put too fine a point on it, but when you can change an opamp (if its modern, hi performance) and hear a change (other than noise floor), one of two things is happening: 1) confirmation bias, or 2) the circuit has a design flaw.
That isn't me saying 'any modern opamp has no sound'!
What I am saying is that if you know how to design with opamps, and if you compare high performance opamps, then you will not hear any difference other than perhaps the noise floor.
I know there are companies that make a living selling opamps based on them having a 'sound'. But any engineer finds that sort of thing to be a facepalm event. It means either the opamp is poor performance compared to what is readily available (and probably for a lot less money) or the circuit in which it is used is poorly designed, or both.