Check with your manufacturer before changing the tube.
You can put any brand of 6SN7 without issue. But most circuits require changing some resistors to set the operating points of the tube if you change the tube number. Some tube are even wired differently and you may get an unwelcome light show.
That said the Mu for a 6SN7 is rather low, about 20. "the gain" So if your using it in a line-stage maybe you could do without the line-stage and go passive.
You can put any brand of 6SN7 without issue. But most circuits require changing some resistors to set the operating points of the tube if you change the tube number. Some tube are even wired differently and you may get an unwelcome light show.
That said the Mu for a 6SN7 is rather low, about 20. "the gain" So if your using it in a line-stage maybe you could do without the line-stage and go passive.