The OPA165x are an excellent choice for guitar input circuits as a result of the high input impedance and ultra-low noise performance. Figure 8-11 gives an example of a basic guitar input circuit to differential XLR schematic. The logarithmic taper potentiometer shown in this circuit provides 6 dB of gain at 0%, and 40 dB of gain at 100%. The rail-to-rail output swing of the OPA165x allows for a high amplitude swing at the outputs of the differentially configured amplifiers, while maintaining very low distortion performance. A 10-µF dc blocking capacitor is used in the feedback of the noninverting stage to remove any dc offset as a result of the amplifier offset voltage. However, this dc blocking capacitor can be eliminated for applications that are not sensitive to low dc offsets.