Help with inverted phase Newbie Question

Alrau1: If both my preamp and CDP have phase inverted, do I need to swap the speakers leads? The reason to invert the phase from my preamp is that it could reduce the hum from my system quite a bit. Thanks.

If you invert twice, you are in phase. Inverted phase is 180 degrees out of phase. Invert again, you are 360 degrees out of phase, which is really 0 degrees out of phase, which means you aren't out of phase. If that makes sense.

Edesilva's response was right on the money, so the answer is no. But, where did you get the idea that inverting phase reduces hum?

I have heard about somehow inverting power prongs might possibly resolve the ground loop/hum problem. Even though it doesn't work for me that way, it gives me the idea to try inverting the phase from my preamp. This works for me, but I am still trying to figure out why...

Jshaw,

This thread is about absolute polarity, AKA The Wood Effect. You are talking about reversing line and neutral on your power connections. It is generally recommended that, on equipment with 2-prong AC plugs, you should use the direction that sounds better, or if you can't hear a difference, use the direction that results in the lowest AC voltage reading from the equipment chassis to ground. With 3-prong plugs, the only way to do this is with a "cheater" (an adapter that plugs into a 2-prong outlet, with or without a ground lead). I am strongly against using these to lift the ground because of the safety issue, not to mention that your after-market power cords will not do their job properly without a good earth ground.