Based on everything I’ve learned, I have a simple theory on this. I’m sure the physics will back up what I’m saying here, but I have to say I don’t have much time to do the thesis. Maybe an aspiring physics doctoral candidate who loves vinyl might opt to do their thesis on this topic.
And so the theory goes…
Recording digital onto vinyl brings the mechanics of motion physics into play. Where DACs work to represent sound as electric signal approximations subject to Electromagnetic physics, the representation of sound conferred by tracing grooves into vinyl are subject to, and limited by, Newtonian physics.
Most DACs try to represent a sound wave by approximating the curve of the line between two sample points. That approximation often extrapolates additional data that do not exist in the original signal. The better ones try to draw a bezier curve. The worst ones draw a straight line.
So what does a cutting lathe draw? With a vinyl cutting lathe, the movement of the cutting stylus is bound by the properties of and limitations of the physics of the stylus against vinyl. Newton’s three laws of motion governs the stylus movement and limits how the groove can be shaped.
As such, vinyl is unable to track wave motions that exceed it’s physical limits and acts like a band pass filter for signals that can only be accomplished via the limits of carving a curve into vinyl… kind of like a car that understeers when taking a sharp corner.
Why does this sound better? My best guess is that vinyl limited motion is physical in nature and our ears are built to understand sounds generated from tangible, physical interactions. Digital waves are unnatural in that they do not originate from physical phenomena, but rather an approximation of a sampling of physical phenomena… at least until they’re cut back into vinyl.