Back to the resistor question, if it's the first stage of a moving-coil pre-amp or the first stage of some microphone pre-amplifiers, then low resistor noise is important! There is not much wiggle-room in those first stages but 40dB later at line level signals, any quality resistor is fine.
We are at a point where test instruments can measure extremely small values and Audio Precision likes to point out all the measurements that their expensive meters can do.