STAX SRM-007TA SRM-007TII DRIVER UNIT HEADPHONE AMP [Japan Import] Frequency characteristics DC ~ 100kHz / + 0, -3dB SR-007 1 units when using Rated input level 200mV / 100V output when /  maximum input level 30V rms / Volume - No minimum when Input impedance 50K / balance when 50K  2 /  maximum output voltage 340V rms / 1kHz Power voltage AC100V  5%, 50 ~ 60Hz Japanese manual included