In audio, a buffer is the name of a circuit block with a voltage gain of unity (0 dB), a high impedance input, and a high current, low impedance output. Although the current drive is usually the headline feature, when used open loop a buffer also isolates the high negative feedback voltage gain elements of an audio circuit from the difficult to drive, and potentially instability-inducing, capacitance and inductance of a complex load such as a long length of interconnect cable or a pair of headphones, to give the most common examples.