Buzz coming from preamp when off

I have a low level buzz sound coming from my preamp, audio research ls-16 when it is off. When it is turned on it's a little louder, and when i turn the amp on it is amplified through the speakers, but not that noticeable at my listening position, and does not get louder as i turn up the volume.I have disconected my cables from the amp, and the cd player and the noise remains.I have a dedicate circuit for system with nothing in the room eccept my stereo.I have a rotel 970 cd player connected with kimber hero half meter rca, and a mccormack dna 2 deluxe connected with a meter of yba diomond rca, and a pair of dynaudio 1.3se's connected with 4 foot pair of kimber 8tc.I did not have this problem with my previous solid state threshold preamp. Any help would be apprciated, thanks.
Forgot to mention i also used a two prong adaptor to my power cord with no luck.
It sounds like you have a transformer buzzing in the preamp since it happens with the system off. I suspect the buzzing you hear from the speakers is from the amp and not coming from the preamp since it does not increase when turned up. I am not familiar with your equipment but torroidal transformers are known to buzz with dirty AC. The fact that the buzz increases when turned on also points to the transformer in the preamp.

A buzzing transformer usually happens from one of two reasons.

1. The transformer is defective. The laminations have separated and now buzz.

2. It is being fed a noisy AC signal. Having a dedicated line does not isolate it from the rest of your house. Light dimmers are notorious for causing noise on the AC line. The dimmer from my stove hood in the kitchen causes my isolation transformer in the basement to buzz. Turn off all breakers except the one feeding your system and see if it goes away. Then turn them on one at a time to see what line is causing the noise.
Thanks for the advice Herman, i turned all the breakers off in the house except the two dedicated lines, and the noise is still there.Must be the power outside feeding the house then . I brought it to work today and pluged it in and the noise was hardly audible, thanks, Yeti.