I lowered my noise floor on the cheap........

I run a dual use system so I run a APC battery back up incase of power interuption so i can shut down Projector and let fan cool bulb to avoid damage. So I got bored and wondered what if any improvement I would get if I ran Phono Stage into that unit and unpugged it to run on DC so after I fished wires, I unplugged the backup shut off alarm and listened for near 3 hours enjoying the dead silent back ground I never had before, all hum was gone. I dont have a super awesome analog rig, SOTA Star/Saphire tweaked Rega 300 arm, AT oc150 cart and Musical Surroundings Phono with Kimber Hero wire but man it was really easy to hear the imediate improvement..........not sure how much over 3 hrs I can listen on battery but it was a cool upgrade, Cheers
Well I dont have money or good health to really do much with my system so if it is better...its better and I dont care why I just cant do the things others can here.
The unit I use is just intended for the 2 minute fan cool down cycle incase of power outage on Projector so I have never used it casually before last night when I ran the Phono.
IMHO, lowered background noise when you switch to battery power indicates that your equipment's power supplies, or the grounding scheme of your system ain't so hot. I have never had a system, cheap or expensive, that I could not get to be quiet. Sometimes it took quite a bit of trial and error experimentation.

One exception would be tube electronics (Heathkit preamp) that used AC filiament excitation, where I couldn't get the hum to completely go away. This was back in the 1950's.
Interesting. Which particular model are you using and how does it compares in utility time using your projector vs phono stage?
That is a neat experiment , a friend of mine converted almost his whole system over to battery power except for the power amp. He had about a dozen gell cell batterys sitting on the floor all around his system. I haven't seen him in years he since moved away and lost touch with him, but that was the quietest system i had ever heard. The background was absolutely pitch black .From what i remember he could go a week or so before he would recharge the batts.
I recently purchased a Moon Audio 5.3 phono preamp that has a outboard DC plug in . I am waiting for Moon to come out with this outboard DC upgrade i am hoping it is a battery powered option cause this is a super quiet preamp and if it were battery powered it would be awesome.
Yes APC make good equipment. Electronics does not have to have a four figure price tag to do a great job. Your comment about "cheap" shows that you are preparing yourself for the kind of remarks reserved for those using industrial business products like APC instead of "boutique" Hi-Fi ones...