What effect does the input and output resistance of the amplifier have on the amplifier? The input resistance of the amplifier should be as high as possible. This can increase the effective output of the input signal source and reduce the effective signal consumed by the internal resistance of the signal source to a minimum. The output resistance should be as low as possible, which can increase the effective output signal ratio on the load. Engine Parts Belt,Water Pump Belt,fan belt,dynamo belt Chongqing LDJM Engine Parts Center , http://www.ckcummins.com