If there is no hum with the cable box DISCONNECTED from everything in your audio/HT loop, then all is well with your equipment, i.e., it is the cable TV stuff. Make sure the cable coming in from the pole is grounded; if not, call your cable company and tell them your situation...I've read that it is their responsibility from the local PUC/building code, etc., to ground their equipment when entering a home. Also, check out the other thread-
http://ubb.outlawaudio.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=92252&page=3

Hello People,
The frustration gets better.
I picked up the 7700 yesterday. It had been running on and off for eight days and there was no hum.
Today I just connected the 7700 to the outlet. HUM.
I did disconnect my cable service. HUM
I checked my circuit breaker box looking for any lose wire. No luck.
The last thing I did having some success and I am hoping that someone here on the Forum can give me good advice. I have a 50' extension cable...three prong and first I plugged the extension cord in a bathroom outlet twenty feet away.
NO HUM.
Next I used the same extension cable and plugged it into the same outlet as I would plug the 7700 into. NO HUM.

Great, right? How do I solve this problem? Better yet. What is the problem? I certainly do not want to have a 50' extension cord in the loop. I do not have a shorter extension cord (10') to see if that would work but I intend tomorrow to borrow one and see what happens. I do not know if they made a 10' heavy duty extension cord.

I spoke to Scott and he was his usually self...helpful. He admitted he did not want to offer any advice b/c he really was not sure what the problem could be. He said he would get back to me as soon as he speaks to one of the engineers who work on the 7700. It is almost 5pm out here in Pennsylvania so I do not think that Scott will be calling tonight.

In the meantime if anyone out there can explain to me what the issue is and how to solve it PLEASE let me know.

Thanks guys

It sure sounds like that circuit is not too well...it may be time to call an electrician. If it's good off an extension cord, then find out what breaker (in your main panel) that plug is connected to; I would assume it is a different circuit then the one the amp was originally connected from. It may be there are too many appliances/equipment, lights, etc. on one circuit and causing problems....like I said, I would call an electrician to further investigate....

I mentioned it somewhere here in the Saloon recently about a hum problem I had.....I had an old lamp with a very unique bulb in it; it was in a room in another part of the house....I noticed a hum in my amp for a few days; for the life of me, I could not figure where in my HT system it was happening, until one day, my girlfriend walks into the other room ( I was sitting in my HT room with nothing playing) shuts this light off.. AND THE HUM DISAPEARS...suffice it to say, I was overjoyed!!! (because amp hums can drive us nuts, LOL)...long story short, is this lamp holds sentimental value for us, but WHEN in HT mode, the lamp is turned off....

Thanks for your opinion. However I have a dedicated HT room and all circuits in that room are prioritized specifically FOR that room. There are no appliances. All of the equipment is connected to a Furman line conditioner except for the 7700. I have four different circuits that I use for my equipment. I have two 20amp circuits and two 15amp circuits.
All circuits were tested for correct wiring. No problems.

I tried all circuits without the extension cord getting the dang HUM. I also tried all circuits using the extension cord and everything is quiet as a mouse.

What are the chances that all four circuits breakers are bad, highly doubtful with this scenario.

Thanks for the advice. I might be forced to bring in an electrician but for now I want to try and solve this problem myself with a little help from my friends.

Thanks again

The only effect a long extension should have is to lower the voltage slightly to the 7700. I guess it is possible that the plug on the 7700 fits better to the extension cord than to the receptacle. I would check out the plug on the 7700 to make sure it is fitting tightly to the receptacle and that all the connectors are clean and shiny.

Thanks XM
I have tried everything you suggested...to no avail.
Tomorrow I might physically check the receptacles but what are the chances that both 15 amp circuits and 20 amp are malfunctioning?
Maybe Scott was right all along with this about at different times of the day and different times of the year the voltage is different coming into the house.

Personally I don't buy the voltage fluctuation thing. Voltage would have to vary quite a bit to affect the amps power supply. Voltage and frequency are very tightly controlled by the power company. When the hum starts in the evening do you notice a change in the intensity of your lighting or anything like that. Could the power cord to the 7700 have been damaged at all. Can you try another cord. You may be able to borrow one from the guy that worked on your amp.

I don't really believe in the high voltage thing either. I guess I am getting desperate and more frustrated.
I have two power cords XM. One is the original power cord I got with the 7700. The other cord is a power cord from Tributaries that I pick up cheap fro a friend of mine. I did interchange cables trying to solve this problem.
I might touch base with an electrician.
The thing that really puzzles me is four different circuits and the same results.

Have you connected the 7700 to the power conditioner to see if that helps? Here is a long shot. Try leaving the 7700 on and one by opening each of the breakers in your main power panel (except of course the ones feeding the 7700) including the 220 volt breakers. At this point since we have kind of ruled out the 7700 it has to be something upstream. Maybe some load on your power panel is causing a feedback to the panel. If the noise stops, then reclose that breaker and continue the process to make sure there are not two issues. If you find that the noise stops then figure out what is on that breaker and unplug it/them one at a time.

I have connected the 7700 to the line conditioner..no luck.
Your idea about checking the breakers I am doing today.
I have to say this is very trying.
Yesterday I noticed that when I used the 50' extension cord the hum was still there. Very low in volume but still there. It was so unnoticeable I had to put my ear to the basis of the 7700. This has me thinking that I wonder if the place I bought it to did not hear it. However I was there when it was running and I did not hear anything myself.
Thanks...I will be posting today's result later today or late morning. I have to get myself together before I start to look for anything.
A thought I have is I have an old Yamaha receiver. Only 100 watts. I wonder if I plug it into the outlet in my HT room if the HUM would be there? I don't know if that's the way to go.
I still have not heard from Scott but was talking to him yesterday and he wants to talk to one of their engineers who worked on the 7700. If nothing positive happens today I should hear from him by Monday , Tuesday.