Tube Rolling

Hi,
Power tubes when lack dynamics, loose treble and have difficulty in bias, driver tubes when becoming noisy. How fast will power tubes wear? Depends from how hard they are driven in circuit, your speaker and your listening habbits. Always get matched pairs or even better matched quads. When i had my SF Power 2 i liked SED6550C (not Svetlana) best to anything else but i had to replace them every 700hrs.

HI,
Getter is the metal (various shapes) that is connected to a hot electrode and is to collect free gases for tube to work in a vacuum, they are coated and loose some shining with use. The underside top of glass is metal particles (silver colouring) induced when sealing the tube. In power tubes they fade away with use. Driver or signal tubes get hazy marks or spots and a white ring at nipple base.