Abstract: A musical string instrument (12) has a body (21) with a resonate cavity covered by a soundboard (22). A pick guard (34) has a flat surface for mounting to the soundboard of the instrument. Electronic control components (36) are mounted within a housing of the pick guard. The musician can control a preamplifier within the resonate cavity of the body with knobs (58) and push buttons (60) located on the pick guard. A thin, flat, multi-conductor ribbon cable (38) is connected to the electronic control components and routed along a surface of the soundboard and through a sound hole (24) in the soundboard into the resonate cavity of the body. The ribbon cable entering the resonating cavity through the sound hole does not adversely effect the natural response, performance, sound quality, and tonal property of the string instrument and does not require any additional holes be drilled in the soundboard.

Abstract: A musical string instrument (12) has a body (21) with a resonate cavity covered by a soundboard (22). A pick guard (34) has a flat surface for mounting to the soundboard of the instrument. Electronic control components (36) are mounted within a housing of the pick guard. The musician can control a preamplifier within the resonate cavity of the body with knobs (58) and push buttons (60) located on the pick guard. A thin, flat, multi-conductor ribbon cable (38) is connected to the electronic control components and routed along a surface of the soundboard and through a sound hole (24) in the soundboard into the resonate cavity of the body. The ribbon cable entering the resonating cavity through the sound hole does not adversely effect the natural response, performance, sound quality, and tonal property of the string instrument and does not require any additional holes be drilled in the soundboard.

Abstract: A combination of limited data, 3D linear interpolation, and a unique simulation circuit are combined to provide a programmable tone control that can simulate any desired tone stack. In accordance with one aspect of the invention, it has been found that a reduced number of data points plus interpolation provides sufficiently accurate coefficients for simulation. The data points are obtained from measurements of the actual operation of the analog tone stacks to be simulated. A second aspect of the invention is the simulation circuit controlled by the coefficients to accurately reproduce the operation of any given tone stack. The simulation circuit uses two programmable filters and three variable gain amplifiers to simulate a tone stack. The cut-off frequency of each filter and the gain of each amplifier are determined by coefficients extracted by interpolation from stored data.