Air level in VP26 and VP 28 Classic API modules

Hello, I've recently completed two Classic API VP 26s and a VP28. The modules are in the 51x Rack. when i plug a mic into them i immediately notice the level of air is louder than usual. I have no experience troublshooting in electronics. Does anybody know what too much airiness signifies? The pres are working fine but the air that usually arrives when you turn the gain up too high is arriving at normal levels. Thanks in advance for any help here

air???? or did you mean noise?