Try this:
http://diyparadise.com/dablok.html
to remove that pesky DC from your mains supply. Remember, only a few mV of DC can make toroids hum like there's no tomorrow. I used this same basic design when I built my DIY Armegeddon-clone power supply for my Linn, and it cut the mechanical noise in the 1:1 isolation toroid by about three quarters (yes, it's that effective). Check DIY Audio for the abundant debate on HOW this circuit actually works. Pretty spiffy if you ask me. Regards,
-Richard
http://diyparadise.com/dablok.html
to remove that pesky DC from your mains supply. Remember, only a few mV of DC can make toroids hum like there's no tomorrow. I used this same basic design when I built my DIY Armegeddon-clone power supply for my Linn, and it cut the mechanical noise in the 1:1 isolation toroid by about three quarters (yes, it's that effective). Check DIY Audio for the abundant debate on HOW this circuit actually works. Pretty spiffy if you ask me. Regards,
-Richard