Vacuum Tube Manual for Audio - Permanent Preservation Edition Yoshinori Ichiki Radio Gijutsu-sha The outer cover of the manual has some scratches, but the contents are almost unused, so I think it is a "beautiful item" without any folds. Please check the condition in the photos. We are waiting for your purchase if you understand that this is a used item stored by a private individual. Vacuum tubes for audio Vacuum tube amplifier