Help with system/ARC noise

If you plan to keep the Oppo 105, checkout getting it modified by ModWright.    I think Oppo 105 supports DLNA so you can run DLNA server, ie JRiver, on a computer and use the Oppo as a DAC.

From my experience, I suggests adding dedicated 20 amp lines just for audio, upgrade your AC outlets with Furutech's GTX-DR-NCF Receptacle and get a power conditioner or power distributor.    

As tomcy6 mentioned, power conditioners can be tricky.   I've had many and prefer a power distributor Weizhi PRS 6.  My brother has a Shunyata Triton and he loves it.    Have heard good things on PS Audio P10.

Once you have a good foundation, try different PCs. after market fuses, IC and SC ... 

You already have a good amp, pre and speaker so off to a good start and no need to rush.

Update: I added a richard gray substation and 600s conditioner so i have enough outlets for the entire dystem. After updating oppo's firmware the noise was gone for a while then came back. I was really having sleepless night thinking how yo solve the problem. My last resort was to change the tubes on my preamp. After inspection i noticed some white powder residue on the biggest tube of my arc pre amp though the tube looks new. After changing the tune ghe noise was gone- yay!

Glad to hear that everything worked out.  How does your system sound now?  Does the power conditioner improve the sound?  Enjoy!

Tomcy, after resolving the issue i decided to separate my 2 channel system from my hometheater in which im running it with my oppo 105D. I recently added an EAT C Sharp turntable so i'm only using my 2 channel system purely for vinyl and when i want to listen to digital i go back to my oppo/HT and switch it to 2 channel. I am so happy with the sound of my system now. Its my first time to vinyl and all i can say is wow! The clarity and separation of vocals, instruments and transition of drums is so transparent and way way far than when i'm listinning to cd's or losless audio streaming using my oppo. I dont know if the power conditioner help or its because of the equipment but all i can say is i am enjoying my music. The only downside is i have to flip records every 20 min. 

Panda-

Glad you got your system sounding great. I have an LS-17  and DS-450 with a Sony 5400ES and it sounds incredible. I can only imagine what a spanking your ref5se would give my LS-17. What cables are you running?

The new synergistic research uef black power cables and fuses have really raised the bar for my equipment. The take all the fine attributes of your system and make them shine.

 The DS-450 took a LOOOOONG time to come around.  I honestly  thought it was nothing special for the first month I owned it and felt it was flat sounding. It sounded like it had no air and only had good bass. Only  After about 2 months it began to sing sweet music, and my fears melted away. I concur about the imaging and separation. The DS 450 is an underrated amp imho. They are excellent amps.

 I also use a furutech gtxd r with the matching plate and cover. Interconnects are morrow ma-5. Feeding my Maggie 1.6, it's an entry level system that sounds waaaaay more expensive than it has any right to. Transparency in spades. I too would have sleepless nights if I had been in your situation. Glad you figured it out.