NOS Mullard, Siemens or Telefunken rule IMO. OLD Tesla were robust and made to last, don't know if the same could be said of the new. It is a scientific fact that cryogenic treatment is futile unless you use HUGE magnets to orient the molecular grain structure of the metal components in the tube at 0 degrees Kelvin. Something like a MRI scanning magnet should suffice. This orientation that actually does have some performance benefits to electron flow will be affected adversely as soon as the valve is heated in use. I suspect therefore that the benefits would be marginal at best. Aside from perhaps stress relieving the tube. The benefit is I suspect to the tube sellers in the way of value adding.
Tube el34
Hello, I'm in the process of upgrading my tube on a Conrad-johnson cav-50. I used Electro-Harmonic at the moment. It is possible to by Match Quad of them. Witch el34 out there is the best sounding? Mullard el34? There a process of cryogenic blabla to -300? is it good?
Thank you for your time
peter
Thank you for your time
peter