A new Design for Audio Clipping Pre-amplifiers based on Silicon Control Rectifiers

This paper presents a new engineering approach to audio clipping preamplifier that can be used for the tone modification and volume control of electronic devices. The approach consists of a unique design based on a summation amplifier, Silicon Controlled Rectifiers (SCR) and RC networks that enables signal gain, improved frequency response, tone modification and signal shape clipping. The proposed summation amplifier based design produces more gain resulting in larger range of clipping effect as compared to existing methods. The response is altered to produce low bass frequencies that have been amplified based on a new configuration allowing the user to change the reactance within the summation circuitry. Also, a new technique of Silicon Controlled Rectifiers (SCR) with a variable RC network accomplishes a clipping network that adjusts the shape of clipping signal. The main advantage of the proposed amplifier is that it can generate a wide range of tonal control that to date the industry has yet to produce. The proposed method being an analog approach also addresses current drawbacks found within the digital preamplifier which fails to effectively capture the tone quality of the individual analog devices. The paper explains the design details, simulation set up including analysis, real-time testing/trouble shooting on an electric guitar and constructional details. Introduction The notion that distortion produced by an amplifier could be beneficial to tone, dates back to the early days of guitar amplification. Before solid-state devices, all guitar amplifier systems were powered by vacuum tubes. When these amplifiers were operated at high audio levels, their power tubes would operate in saturation, thereby producing a pleasing clipped distortion and of the guitar signal. This distortion produced by vintage amplifiers is a greatly sought after sound in modern guitar amplification. Modern tube amplifiers are able to achieve vintage distortion, but