All of a sudden getting a hum in my system?

I am getting a hum that gets louder as you turn up the volume. I disconnected my VPI Classic One turntable and I am still getting the hum.I disconnected my three month old Manley Chinook and hooked up my old Belles 20A phono pre-amp and there is no hum. So the Manley Chinook seems to be the culprit. I called Manley Labs yesterday but they are closed until January 2.Any suggestions for resolving this problem would be greatly appreciated.