humming in my system

I get a noticable hum in my system and I can't figure out why. My shunyata hydra 8 is plugged in to the wall with the python power cord. pretty much every thing else is plugged in to the Hydra. Any thoughts?

The ubiquitous ground loop hum.

Do a search of the threads for "ground loop", "hum", etc.

Many suggestions and techniques will be found.

Sorry I could not resist.
As Tvad has said, this has been discussed many times before, so perform a search of the archives.
From what I can recall, usually the main culprit is cable tv. If you have cable tv, disconnect it and see if the hum goes away. If so, there are ground loop isolators out there that will help you.

Start with process of elimination diagnostics.

Unplug everything (including interconnects as well as power cords) except the amp to the speakers. Do the speakers still hum? Is it one channel or both? If it hums with nothing else hooked up, then you probably need the amp looked at.

If there is no hum with the amp only, start adding components back one at a time. When the hum returns, try some other combinations of equipment to see if you can further isolate the source.

Try a different set of interconnects and power cords to see if you might have a bad cable. If you get to where it works, then you may have located either a defective cable or one that simply isn't suitable for your setup.

There are additional things you can try (floating grounds, using one power outlet or using two different ones, etc.) but the initial goal is to simply isolate the problem. Once you've found the hum source then you can start working on the solution.
Silly as it may seem, I used a GE 2-3 grounding adaptor on my power amp power cord and the hum is gonnnneeee!! Cost is about $3.00 for a two pack in staples. Maybe your problem is more complex, but for $3.00, worth a try!!
I use the humbuster to great effect.
thanks to all of you!!
Another thing to try after going through all the procedures above is to get some wire and try grounding the chassis together in various arrangements and also to a known ground such as a screw on an AC outlet. Oftentimes your components can be at different ground potentials and you are hearing the residual 60Hz hum as well as RF and EMI traveling in ground loops. If you get everything grounded to the lowest potential you may eliminate the hum. I have done this many times myself. I would use a 3 prong to 2 prong cheater plug as a last resort, as you can sometimes incur a dangerous shock situation. This happened to a friend of mine and it scared the bejabbers out of him.
Probably the toughest thing to figure out and solve is hum. I had a hum, and it turned out to be a bad interaction between two pieces of gear. I swapped gear, and the hum went away completely. Go figure.
pretty much every thing else is plugged in to the Hydra.