New Raptor Has Low Level Hiss, What to do?

I received a new Raptor amp from Ray and the first thing I wanna say is it sounds absolutely beautiful and dealing with Ray was the best. Ray really seems to love his craft and takes pride in his work. I have a computer and Ultra micro DAC and some accessories plugged into a power strip and then the raptor is plugged directly into the same wall socket along with the power strip. This configuration produced a hiss that was audible when the volume was low or the music was very simple. I tried a 2 prong adapter and that made an improvement but wasnt a total solution, but it reduced the hiss to a level where I cant here it when I listen to music unless there is a pause or extremey low point in the music. I moved the amp to a different wall socket and that socket has no other devices on it. That didnt improve the situation either. The hiss reminds me of an HK PM655 amp I had in the eighties, it made a similar hiss with no source running and you put your head next to the speakers but was not audible just sitting in the room. It is definitely not a hum, its a hiss. I have an extremely nice interconnect Jacob at Soloz Audio made for me and it is a night and day difference because when I first got the amp I had a fifteen dollar cable from best buy and it sounds like crap so its not the cable. Jacob was also very nice to deal with and had extremely good communication. The power cord is a 14 gauge unit I got from PC Power And Cooling. Its cheap but built real solid. My question is this, will a power conditioning power strip eliminate the hiss I can hear. Also, is this normal with an amp like this? I think it is but like I said, last time I heard something like this was a super nice amp I had 20 some years ago. If you think I need a power conditioner let me know what brand or what models you like. I don't wanna spend a fortune, 100 to 200 would be nice.

Its both channels and switching the 5687s didn't seem to have any effect. This is my first tube amp. Also I should say that the noise is more apparent using 300 Ohm 650s as compared to 62 Ohm 701s. Have no idea what that means but maybe someone out there will. I also live in an apartment building and the noise is faint or non-existent late at night.

Bump

Thanks everyone!