... 1) Professional stereo power amplifier with transistor 2) Reliable protective device for short circuit, overload and over heat PL Series Power Amplifier ... stereo power amplifier with transistor. Features are Input Gain, Ground Lift Switch to eliminatehum, Power LEDs, Channel 1 & 2 level, ... , Ground Lift Switch to eliminate hum.12) Power LEDs, Channel 1 & 2 level, LED's indicator, stereo and bridge ...