Static from tubes

After watching and listening to some reviews I decided to purchase a Schiit Audio Freya plus preamp. I replaced the Tung-Sol tubes with General Electric GTBs and at least in my system, the separation of instruments was better. This was in March, 2019. I was quite happy at first. Twice, here was some static right after the tubes were changed, then it disappeared. At this point I am again getting static when I use the tubes. I looked inside and the inserts look pretty cheap (plastic).  Is static common with tubes, or is this unit just have this one part of it that is cheap? I am trying to decide if there is a tweak or repair for this, or if I should just sell it cheap and move on. Any ideas? 
Is the preamp close to your router?
On mine (saga with Tung sol) I notice, that the static is worse (when a web page loading, more data being transferred, etc...but my router is about 5 ft away, unfortunately. Can't put it elsewhere due to WAF. As a test turn off router and network devices in the house to see if it gets better.

Its about 16 feet from my router, but not necessarily from my neighbors. I may have to move where I am placing my preamp if this is the case. I'll talk to my neighbor. Thanks. 
Diagnosing remote like this is fraught with peril because there's a few different things it could be and without being there... oh well ... the key comment to me is you said its the same thing one set did right at the beginning but then not after that. There's a technical reason I forget, something to do with the guts inside not being absolutely clean leaving residue that occasionally gets energized and moves around and that's the noise you're hearing. 

If that's what it is, it can be anything from one and done to intermittent and only every once in a while to almost nonstop. I have one that's intermittent every once in a while- and never heard it even once while playing music. Only at idle. So for me its not enough to be worth the bother of replacing it.

However, after long experience with tubes it seems to me if a tube is silent for years and then starts developing this same noise, that's a sign the tube is on its way out. Yours are way too new for that. But something to keep in mind.

Unfortunately for me, if the volume is low I can still hear the static even during play. Thanks for your response. I try to keep a pillowcase over the unit and remove it during play but I was not doing this early on.
Sure sounds like noisy tubes to me. Was this 'static' present when you used the Tong sols? Do you still have them. If yes and yes simply changes back to the tong sols. If they are quiet then you know that your problem is related to the tubes you are now using.

The solution then is to get tubes that are tested for low noise (new, NOS, or used). Age has little bearing. New tubes can be noisy.  Noisy tubes can last a long time. In my experience this is is not a typical sign of aging. Forget the pillow case unless you think cleanliness will make a difference. My tubes/amps get dusty as hell with out negative effect (I do dust them once in a while :-).
Have you tried pulling the tubes and re-seating them?

Depending on how comfortable you are handling tubes, when they are out, give the top of the glass envelope a firm tap with the eraser end of a pencil.  Use the same sort of force you might apply to a light bulb without breaking it. 

Could be a bit of stray (flashing?) has gotten caught on some of the inner structure and dislodging it will eliminate associated static.  Check Brent Jessee's website FAQ for some related guidance.  Sometimes the act of pulling them and reseating them will dislodge the debris and solve the problem. 

If you do pull the tubes consider swapping L & R channel tubes.  Ensure the static noise follows that move.  I'm assuming not all your tubes are causing the noise.  

I own a first gen Freya and have had various pieces of tube gear over the years.  Intermittent static noise from tubes - esp. NOS, is not unusual. 

Clean the bases of the tubes and the surface of the tube sockets with isopropyl alcohol. Problem solved! 🤗
@ Newbee both tubes had static that I noticed only after changing the tubes for the third time. I tried a combination, and I used both sets. 

@Ghosthous. changing the tubes is what seemed to cause the static. It started, then stopped after a bit. Then again after another change, and finally the third time the static has lasted longer. I think I will take your and goeffkait's advice and do some cleaning. Then I'll take it from there.  

Ricky -
Are you hearing static in both channels or only one? If you move the tubes to opposite channels, does the static move to the other channel? In the first gen Freya, the rear tubes are right channel and front tubes are left channel . If the static persists in one channel after moving tubes and after cleaning, check interconnect connections. Anything loose?

If none of that helps - especially if the static is fixed in one channel - consider filing a claim with Schiit. The Freya has a 5 year warranty.

Good luck.