2 Tubi Aspirazione GE 5-Star 5687WA/WB - Piastra Nera Doppio Triodi per Amplificatori AudioNote
Output is rated at 8.4 watts. Introduced in 1948, the 5687 has been used by Collins and IBM. Recently it has been adapted for audio circuits, such as in AudioNote Amplifiers. 2 GE 5-Star 5687WA / WB Vacuum Tubes.