i built this DC motor power amplifier to drive the motor in both directions using an analog signal (from -1 volt to 1 volt via the potentiometer ) , the motor i use is rated for 24 volts and draws around 400mA at no load , however, when i tested it only one direction works fine ( the NPN TIP142 side) with no significant heat , the other side however doesn't drive the motor all the way to 10 volts and the PNP transistor becomes hot real fast, i replaced it with another tip147 but still got the same results, any idea what maybe causing this?
