The Audio by Van Alstine (AVA) Super 70i, a classic modification of the Dynaco Stereo 70, provides a warm, engaging tube sound with improved definition over the stock unit. While offering a lush midrange and good soundstage, This amplifier playing perfectly and sounding silky smooth, no humming or buzzing noise at all, Comes with (4) matching Mullard EL-34 Russian Tube, (1) RAYTHEON 5U4GB Rectifier tube and (2) driver tube made in china. Thanks for watching