I would really investigate balanced power. It isn't hard to do and IMO should be done before any of the above suggestions. The problem is, that the above solutions are filtering (or trying to) the AC noise right at your equipment. Balanced power eliminates all of this noise at the balanced power transformer. The noise doesn't have to get near your equipment.
I use a transformer very similar to this one:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=4665&item=3841823666&rd=1
I have mine sitting on the floor next to the dryer.
Apparently you can hook your tv up to this also and get a clearer picture. However, if you want to hook up too much equipment, you need a bigger transformer. Something around 5 kVA. 3 kVA is plenty to run your stereo equipment. My transformer is 2 kVA and I run the same amp as you and a cd player and a turntable and a small turntable light off of it.
Here's what you do:
1. Get the above transformer or ask your local electrical contractor if they have an old one laying around which would probably make it cheaper. No shipping. I found my transformer in an old outbuilding here on the farm. It hadn't been used in 40 years. Except for having to clean out mouse****, it works fine.
2. Go to Home Depot and get at least a 16 guage three prong extension cord and get a plug that will plug into the 220 volt outlet of your dryer or oven or hot water heater. This part cost me $13.
3. You cut the extension cord and wire it to the transformer and discard the plug end and install the dryer/oven/220v plug so that you will have 220v going into the transformer and 120v coming out of the outlet end of your extension cord. You run this to your equipment and plug it in. What you get it 2 legs of 60v coming out of your plug. These two legs are out of phase and you get common mode cancellation of the noise on your AC line. Instead of a 120v leg and a neutral leg which your normal household outlet is giving you.
4. This way you can try it and if you like it, then move the transformer or run 220v to the living room (this is what I am going to do). I can almost guarantee it will astound you. I too, live in an old 2 prong outlet house. The place where you have a ground is the 3 prong outlet of your dryer or oven or heater.
Feel free to contact me if you would like to go this way. It is cheaper and a lot less hassle than soldering in stuff to your amp.
I used to hardly ever listen to my cd's. They just sounded terrible next to the vinyl. Now the cd's sound pretty darn good and I find myself listening to them a lot more. It makes the vinyl sound even better. I highly recommend it!