Paul_B, I agree. You avoid the noise if you hook the audio in the circuit next to the op-amp like I have it drawn in my diagram---- "above"--- of the "Proper way to bias an Op-Amp for audio."
Grumpy_Mike has presented his way of biasing a digital pot on the input of an op amp. I have asked that he or someone show me how to bias a digital pot used as a resistance in the feedback loop of an op amp. Hopefully Grumpy_Mike will share with us.