Latency Questions for MOTU 896HD

I am only posting this question here because it has to do with studio hardware and set up.

Hey Steve : since I moved this studio into a larger room in our basement I also had to increase wiring outlets to allow everything to get its own plug. I have noticed that even though I’ve run my powered monitors (Roland D-90) through a power conditioner, there is a small amount of white noise that I get through the speakers particularly, the mouse wheel, makes me a little crazy because it actually shows up on the VU meters in Cubase as well.

Since it is a rainy day and I got out of work early I did nothing more than run a 12gauge extension cord 50’ to the power strip that will now run these two monitors and plugged them into a completely different outlet on a totally different circuit and they are clear as a bell… might you have a suggestion as to what is happening besides ground which I know is good.

ADDED: Received a 46 track midi file from a friend to test. Mostly orchestra stuff but did sound beautiful . at the 64 setting it pushed the performance meter to about 75% real time. Disk doesn’t even show up and the average load is under 15% ( all based on extrapolation of the grid lines on the bar being it appears divided into 25% increments )