Rogue RP-1 slight hum

Good morning all,

I just bought a new Rogue RP-1 pre-amp. I love it! it was like opening up warm taps on a faucet. 

Small issue I have is that when at idle, no music playing, I get a slight high frequency  hum and hiss. I swapped out the stock JJ tubes, and it helped but just a bit. Also shut off the main display, no change. Swapped out the power cable for a nice one from AQ, no change. I've e-mailed Rogue this morning, to see if I'm missing something. 

Any suggestions would be appreciated. 

Thank you