For audio balanced line inputs I use a 470R followed by a BAT720S to the rails. There are 12VMOVs across the rails to absorb the injected current before the 22V rated opamps get destroyed. I also put a 1n cap after the
470R, so the 120p of the combined diodes do not hurt in this application. This way the semiconductors survive even an accidental mains on the input. The 470R resistor acts like a fuse. The BAT720S is 1A rated, cheap and in SOT223. 1A/460mV; 5A/ 0.9V