Abstract: This invention concerns, in a current-controlled amplifier circuit, the combination of output amplifier means having an input conductor and having an output conductor for converting a signal at the input conductor of the output amplifier means to a current amplified signal, feedback means connected between the output and input conductors of the output amplifier means and including a differential pair of semiconductors having a control current output, for presenting a signal at the input conductor of the output amplifier means which is the product of an input signal to the amplifier circuit and the ratio of a reference current to the control current and for substantially eliminating dc input at the input conductor of the output amplifier means and setting the quiescent currents of the semiconductors of the differential pair substantially equal.

Abstract: An amplifier circuit for use with a guitar. It has two modes, a "clean" output mode, and a "super-distortion" mode, which mode has independent gain control prior to a distortion stage. There is also post distortion gain control.

Abstract: A loudspeaker enclosure which is adapted to be easily assembled with other like enclosures. The loudspeaker enclosure comprises a front wall through which sound can emanate, two essentially parallel end walls, each end wall being in the shape of a trapezoid and a back wall. The enclosure further includes two side walls extending between the end walls, each of the side walls having a plurality of outwardly projecting linear ribs extending on a line between the front wall and the back wall.

Abstract: A digital amplifier contains a circuit for converting the onset of a clipping condition into a missed pulse in a pulse width modulated pulse train generated from an analog signal and an improved circuit for producing a control voltage proportional to the extent of the clipping condition, which circuit includes a pulse counter for counting a predetermined number of missed pulses in the pulse train and a voltage generator for producing a voltage proportional to the extent of clipping when said predetermined number of missed pulses occurs. The generated voltage is applied to an attenuator for attenuating the analog input signal.

Abstract: A digital amplifier having a modulator for transforming the analog audio input signal into two complimentary trains of pulse width modulated signals for driving the power switches, which modulator utilizes a precision triangular waveform to control the transformation. The modulator employs all differential processing without saturated transistors to achieve a minimal distortion modulation system. Upon the occurrence of over-modulation, pulses from the width modulated pulse train produced by the modulator are dropped, and the resulting loss of pulses is detected and fed back to a variable gain amplifier stage of the system. The distortion detection system for detecting the missing pulses utilizes a timing network to establish the missing pulse period necessary to begin input attenuation of the audio signal by the variable gain amplifier stage.

Abstract: Disclosed herein is a method and its associated article for forming the neck of a guitar so that a torsion rod disposed within the neck can serve to straighten neck or counteract the tension or bowing effect of guitar strings. The method includes taking two similarly shaped blanks of stock material and routing a center portion complementarily formed to accommodate a torsion rod. Each element of stock material is routed to provide a mirror image of each other and dowel means are essentially disposed to provide further support for the two halves of stock material when they are joined together as by glueing. The terminal longitudinal extent of each of the stock articles is provided with means for retaining the thus assembled stock article for subsequent carving.