Mark Levinson No 30.6

[Old School]

After looking for a nice Mark Levinson number 30.6, I have finally found one. It completes my Levinson reference front end. It replaced my 360S. It was an awesome upgrade. I never knew that bass could be so detailed!

My system consist of:
No 32
No31.5
No 30.6
No 336
B&W 800 Diamonds

My question is, the power supply of the number 30.6 has a low frequency hum to it. I have tried changing outlets. I moved my cables around some. There is no sound from my speakers with the system on, dead quiet. Any other ideas to try to get rid of this hum? I can't hear it when the music is playing. But when my listening room is quiet I can hear it......

I love the mark Levinson 300 series!