Noise from one valve when turning volume up

Hi, everyone.
So here I go, with another thread about noise issues in a tube amp.
In this case, it's a Valhalla 2. I have a pair of Genalex Gold Lion 6922 tubes, and one of them makes whatever channel I put it in make this noise when I move the volume pot.
If I put the valve in the other channel, same sound, in the other channel.
It doesn't affect the sound once the volume pot is still in one position.
The thing is... the pins are clean, very clean, or so it seems. They look pristine. The valves were bought new and have been used less than 50 hours.
Is there anything I could do to fix this? Is the valve defective?
Thanks!

 

You've got a bad tube.

 

As Finut said. Get a new tube.

 

Thanks, guys.
I was hoping it would be something fixable.
It didn't last long.

 

It happens.