Overdrive Stompbox for Bass
Created: Apr 17, 2017
No description available.
This schematic is an analog overdrive effect for a bass guitar. This effect delivers a soft distortion to your bass signal to add fuzz to your sound. Overdrive and distortion effects are most commonly heard in rock and metal songs.
The circuit is simple in construction having five control knobs to dial the users’ desired overdrive tone. First the drive control, which sets the amount of distortion added to the signal. This is accomplished through an op amp with series feedback clipping topology. This topology is generally referred as “soft clipping” and is popularly used in other overdrive and distortion effect units. The topology uses D1- D3 as clipping diodes. These diodes are connected to the feedback-path of the op amp to round out the peaks of the signal. With its configuration shown in the circuit, it produces asymmetrical clipping. Next is the 2-band tone control, bass and treble, where the user can adjust the colour of the sound coming out from the effect. This provides boost and cut for high and low frequencies. The tone control is constructed with a modified baxandall circuit. After the tone control is the blend control. Blend control is a circuit that mixes the dry signal with the overdriven signal. The blend control uses a dual-ganged potentiometer for its function. A common emitter amplifier follows the blend stage as the final stage of the circuit. A level control is also attached at the end of the circuit to control the overall volume of the circuit.
The circuit has a signal bypass where a clean bass signal can flow when the effect is disengaged. It requires a 9VDC power supply with a center-negative plug to function. Batteries is not included in the design for ecological reasons.