I have a hard time believing the RR2150 is old enough to develop a noisy volume control (assuming it has a traditional resistive volume control instead of a digitally controlled ladder attenuator like is used in home theater preamps). Unless you smoke, live right next to the ocean (Orange CA is too far from the ocean) or have some really nasty chemicals open in your house, the volume control shouldn't shouldn't develop noise for decades.

At any rate, I would try simply rotating it back and forth quickly many times and see if that reduces the noise. Usually that does do the trick unless the potentiometer is really shot.

As a last ditch effort, you can try some contact cleaner - carefully - sprayed inside the potentiometer.

However, like I said, I have never seen such a recent component develop a noisy volume control unless there is something else wrong in the circuit. In some instances, a leaky DC blocking capacitor can place DC on the pot, and this will cause noise, but with op-amp based circuits (that almost always use bi-polar power supplies), there is really never any DC that gets onto the audio path.