excessive hum-buzz in speakers

I have a sony 400cd ES changer connected to a classe cp35 preamp which is connected to a sunfire stereo amp which feeds a set of carver alIII's

The classe has an mit a/c cord and my whole system is connected to two panamax 1000's which connect to a hospital grade wall switch.

I also put those funky cardas rc plugs on every unused rca input connector on the classe and the sunfire.

But still I have some serious hum coming from the speakers.
Before, when I only had my yamaha rxv 2095 with the pre-out mains going to a carver tfm35x and a pair of psb golds, my system was relatively quiet. Although the overall sound has improved, the humming is driving me CRAZY!!!

Please help!!!
Humm is frequently caused by ground loops. This can happen in almost any system. There are a few ways to find out. My recommendation would be to unplug everything except your amps (this includes interconnects and power cords). If the humm continues with only the amp connected to the speakers, you can be pretty sure you have an amp problem and it needs repair. If not, then start by plugging in the pre-amp, connect the interconnects and listen. If there is still no humm move on the CD player. Once the humm appears this component is likely to have created ground loop between another component. You can use a cheater plug to lift the ground and see if this stops the problem. Since using cheater plugs is hardly advisable long term there are a few other things that sometimes help, which are as simple as changing where you plug the component in. In some cases I have found no other way to eliminate ground loop hums other than lifting the ground.
Abstracts response is thoughtful, try all his suggestions first. I had the same problem but caused by my cable T.V. antenna wire. I got a little groung-breaking gizmo from my dealer to put in line that made it all better. I am told this same gizmo is available at radio shack for about $3.00. (This explains why my dealer just gave it to me). Could be your problem.
I usually find that a cheater plug on the preamp (and/or antijitter box) usually does the trick unless it's one of the older Sunfires. The original Sunfires had buzzing problems and there is a fix for it. If you plug just the amp in (and speakers, of course) and still get the buzz, give Sunfire a call; they should be able to fix it for around $165.
I had a similar problem, couldn't get the damned buzzing to stop. It was driving me crazy! I switched from a 25' run of single-ended interconnect (preamp to amp) to a 25' run of Goertz Micropurl copper balanced interconnect The buzzing went away! Completely. Thank goodness, it was beyond irritating. From what I can tell, my single ended cable was picking up all kinds of garbage, acting like a very effective antenna for the nasties. Food for thought at any rate. Jeff
I am curious about the actual line conditioners or similar products, Is it's sole purpose basic like in car audio a crossover or something related? Please educate me on this.
usually if all your equipment is running on the same outlet,you wont get ground loop problems,they are caused by differences in potential,between different outlets!i also had a problem with a loud hum,i thought my amp was going out but it turned out to be the cheap banana plugs i was using at the back of the amp!got rid of them, bare wired them in,and tada!no noise,well,except from my frayed p.s audio cable from x-former to preamp.but using my thalia now,its DEAD silent!!!