Tube Troubleshooting

Hi all. I just moved across the country, and when I set up my stereo there was a loud sound of rushing air coming through my speakers. When I played music, the sound of the air was louder than the music at medium-low levels, and interfered with the sound quality regardless of how much I turned up the volume.

After some troubleshooting I determined the 6sn7 tubes in my Modwright Oppo 95 were the cause. When I swapped those two tubes out the system became dead quiet. Is this a case of tubes becoming microphonic, and if so, are tube dampers likely to help in this situation?