Hum and the PS Audio P300

Just been thru this -- Same issues only with a ARC LS-25... My problem was due to 3 issues -- Corrosion on the ground rod and connection to cable ground where cable TV comes into the house (replaced the ground rod and all connection hardware); Found the particular outlet for my HT had a lame connection (grounded with outlet contact to conduit; fixed by purchasing a grounding strap from the hardware store and making a more solid connection); The house ground had alot of corrosion on the water pipe (got new connection hardware and cleaned up the surface with emory cloth); Tied the cable to the outlet ground by using a Monster HTS-1500 power conditioner for the RPTV. After all of this, the ARC is dead silent, the video is perfect, and my stereo has more detail than ever...

Just some things to look at..

As PS Audio gives a 30 day in home trial why not order one and find out. It did wonders for my system. In fact I bought 2 of them.
(PS: I dont work for PS Audio!)

I had very bad hum when I first combined my cable and home theater system, I bought a Mondial Magic box which cured the hum, that was 3 years ago and it has not left my system since!

Let me add my 2 cents on the P300...I've had mine a year and couldn't part with it. It's worth mentioning that the P300 has a RF coax in/out connection on the back (which isn't even mentioned in the owner's manual) that apparently is some kind of isolation device. I route my cable TV through the P300 using those connections, and it completely eliminated my hum problem. If you decide to buy used, make sure you're getting the multiwave option...it makes a significant improvement.

I believe you have several possibilities to resolve the hum.

1. Disconnect all grounds for all equipment and/or
2. Ensure that all equipment is running off the same circuit as the tv/vcr, etc.. Your sonics and equipment especially your amp will suffer as a result or

3. Ensure that all components are running off the same phase of 115 volts at your service panel.

Disconnecting the ground on all outlets should cure the problem while also providing greater sonic benefits since the ground has a way of introducing additional AC noise into the components. In the long run, I would perform 1 and 3 and you should never have a ground loop hum again.

-John