Say fellows, have you modulated an amp

First you get some vacuum tubes to produce an ocillation.  Then you modulate the amplitude of the ocillation.  Pretty good.

I'm modulating モー娘。 via some dusty old Amperex tubes into a pair of Grado HP-1 headphones, why to I spend so much to listen to JPop？ It's late at night, otherwise I would be blasting it through the speakers.