A versatile tone control circuit and preamplifier

A tone control circuit is described which allows a large choice in the high- and low-frequency attenuation or boost and in the position of the tone compensation curves over all the acoustic spectrum. These two controls, which are completely independent, are obtained with structurally simple RC networks. This tone control is included in a preamplifier for music reproduction. The compensation and equalization curves are reported in the paper and the characteristics of the complete preamplifier are described.