Maybe the distortion in the physical disk has some type of signature, and it can be determined whether that distortion is fast or slow. For ex, I would bet tha

Maybe the distortion in the physical disk has some type of signature, and it can be determined whether that distortion is fast or slow. For ex, I would bet that 2x intended speed isn’t simply 2x every frequency in the FFT, when played through vinyl on a physical turntable. Maybe some collection of distortion signals based on disk manufacturing and turntable manufacturing.