... protective device for short circuit, overload and over heat PL Series Power Amplifier (2U)PL Serie is a professional stereo power ... . Features are Input Gain, Ground Lift Switch to eliminatehum, Power LEDs, Channel 1 & 2 level, LED's indicator, stereo and bridge ... ) Input Gain, Ground Lift Switch to eliminate hum.12) Power LEDs, Channel 1 & 2 level, LED's indicator, stereo and bridge ...