Buy 12ax7 tube

It's good that you only hear noise when up close to the speakers. The fact that the noise is constant even with volume down either means your amp is the problem, or more likely it's due to noise on your power line. This is the noise floor of your system, the goal is to lower it until you have a "black background." 

 Your AC line comes from the power grid in your city/town and is shared by everyone in your neighborhood, then it's wired into your service panel, then travels thru all the circuits in your home. At this point your electricity is contaminated, or polluted may be another way to describe it.

A power conditioner is typically recommended and/or a dedicated line to lower the noise floor by  isolating your system from the rest of your devices and appliances.

Your budget will determine what kind of power conditioner to use. A basic unit would be a Furman power strip/conditioner.

Mehdikh423-Following up on Lowrider57's suggestion. I purchased Brick Wall audio surge protector and this helped lower floor noise on my Cayin 50T amp.

https://www.brickwall.com/products/eight-outlet-audio-surge-protector

The New Sensor Svetlana 12ax7 is a very good sounding tube.  I have yet to try a Gold Lion 12ax7  in my amp's input but I have tried a bunch including some nos and the Svetlana is one of the better sounding current production.  JJ ecc83 were dark in my amp, Sovtek LPS were ok but not great,  mullard repop good, tungsol repop good but a little too much energy on top.  The Svetlana is currently in the input of my amp 

Thanks everyone for your advices
I have another question,can bad electricity reduce dynamic of sound and cause bloated bass?

Bloated bass could be caused by speakers positioned too close the the wall or by the amp not having enough power to drive the speakers. But, your amp shouldn’t have this problem.
It could also be caused by the choice of tubes. And lack of dynamics is often due to tubes.

Your power setup could be causing lack of dynamics and muddy bass, but I wouldn’t call it bass bloat. It would be a lack of clarity or transparency. Your components should not be plugged into a cheap multi-plug, especially the amp. Amps need unrestricted clean AC feeding them from the wall receptacle.

As stated before, I recommend that you use a power strip with a short cable (under 6 ft). Also, replacing the stock cable on the amp would provide better sonics; better dynamics, transparency. I think you should start by improving your power to all your components especially the amp.