Where do you guys buy tubes?

I can buy anywhere as long as the seller guarantee it's tubes on test results on what tester but not on emission test.Pay attention for matched transconductance and  plate current.Double triode like 12A( )7,6sn7,ecc88 etc.,they must be matched at least 10% or tighter triode-triode for Gm & Ip,non-microphonic,very low noise and no hum.

Ralph,What value of B+?since  those tubes you got from the seller, he already applied B+ on them when they were tested.And one more thing about cathode poisoning if you run it for 3 days?