Despite the recent trend of digital transformation, the popularity of Guitar-Effect-Pedal (GEP) designed has does not declined. This paper describes the complexity of the nonlinear characteristics of analog circuitry in a GEP, which originates from not only clipping diodes but also the operational amplifier. It is well known that variation in the supply voltage of a GEP influences its sound. Based on this fact, we designed a bias starving circuit to control various transfer functions. Particular attention is paid to the difference between the odd and even intermodulation distortion. Those transfer functions were analyzed, using each 9th-order polynomial approximation. The analysis indicates that the analog specific properties beyond the approximation exist under a dynamic range of approximately minus 50dB.
展开▼
