Buy 12ax7 tube

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.

Another vote for Psvane 12AX7-T11. Rolled them into my Vincent SA-T8 Pre. Massive jump in performance. Very bright initially, but settle nicely after 70 hours or so. Quiet, superb dimensionality, highly resolving.
And yes improving the Power going to your Equipment will help greatly.

Go to Brent Jesse Tubes and read... Tubes are heavily researched for character and tested. He stands behind his inventory.