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US 4,286,492 AGranted
Control for electronic amplifiers
OwnerGuy P. Claretinventor
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OwnerGuy P. Claretinventor
Estimating the term…
A circuit which allows for the simultaneous control of the bias voltages applied to the screen grids and control grids of output tubes while maintaining the ratio of said voltages, thereby providing a method for selectively varying a single plate characteristic (Power Output) of a tetrode/pentode vacuum tube. In the case of musical instrument amplifiers, it is a desirable effect to drive the power amplifier (output stage) beyond the point that said power amplifier is able to reproduce its input signal accurately, hence causing output distortion. Said point is known as the "Clipping Point". A clipping point is most usually achieved at high sound pressure levels which are uncomfortable and difficult to work under. By varying said voltages in the previously stated manner, one varies the clipping point accordingly, and therefore is able to obtain output distortion at variable sound pressure levels.
In a circuit for an electronic amplifier for musical instruments, the amplifier including an output tube having a control grid and a screen grid and including a bias voltage supply for the control grid and voltage supply for the screen grid, improved means to produce and control distortion in the output tube relative to its input by controlling the clipping point of the tube, the improvement comprising the provision of means for controlling the bias voltage level to the control grid, means for controlling the voltage level to the screen grid, and ganged means simultaneously controlling the voltage supply of the screen grid and the bias voltage supply of the control grid so as to change the voltage applied to said screen and control grids together.
A circuit for an electronic amplifier incorporating a vacuum tube in the output stage with at least a screen grid and a control grid, and having a control grid bias supply and a screen grid voltage supply, said circuit comprising:
Dependencies are inferred from the claim text.