Can I Safetly Try Tung-Sol Preamp Tubes in a Herbert?

[tlingen]

Peter, what preamp tube positions would it be safe to try Tung-Sol 12AX7's in a Herbert?

 

[Ventura]

You can try 'em in any spot.

 

[Peter Diezel]

Please check if the y are micro phonic in V1 and V2.

 

[tlingen]

I will check then Peter, thanks. I didn't know if the Herbert had a high voltage cathode follower and I heard it was very bad to use a tung-sol there.