Multi-channel expression control for electrical musical instruments

Claim 1

IN AN ELECTRIC ORGAN, THE COMBINATION INCLUDING, A PLURALITY OF CHANNELS FOR TRANSLATING AUDIO FREQUENCY SIGNALS REPRESENTING SELECTED TONES CREATING A DESIRED MUSICAL EFFECT, FIRST AND SECOND TRANSISTORS CONNECTED AS CASCADE AMPLIFIER STAGES IN EACH OF SAID CHANNELS, EACH OF SAID TRANSISTORS HAVING INPUT, OUTPUT AND COMMON ELECTRODES, SEPARATE FEEDBACK CIRCUIT MEANS FOR COUPLING THE OUTPUT ELECTRODE OF SAID SECOND TRANSISTOR TO THE COMMON ELECTRODE OF SAID SECOND TRANSISTOR TO THE COMMON ELECPROVIDE SIGNAL DEGENERATION FOR SAID CHANNEL, EACH OF SAID FEEDBACK CIRCUIT MEANS INCLUDING CAPACITOR MEANS TO CAUSE VARIATIONS IN FREQUENCY RESPONSE WITH THE GAIN OF SAID AMPLIFIER STAGES OF EACH OF SAID CHANNELS AND SEMICONDUCTOR DIODE MEANS COUPLED TO SAID FEEDBACK CIRCUIT MEANS TO CONTROL DEGENERATION OF SAID AUDIO FREQUENCY SIGNALS IN RESPONSE TO A DIRECT CURRENT CONTROL VOLTAGE APPLIED THERETO TO THEREBY CONTROL THE GAIN OF SAID AMPLIFIER STAGES, A CONTROL CIRCUIT FOR DEVELOPING A DIRECT CURRENT CONTROL VOLTAGE INDEPENDTLY OF SAID AUDIO FREQUENCY SIGNALS, AND CIRCUIT MEANS APPLYING SAID DIRECT CURRENT CONTROL VOLTAGE TO SAID SEMICONDUCTOR DIODE MEANS OF ALL OF SAID CHANNELS FOR CONCURRENTLY CONTROLLING THE GAIN OF ALL OF SAID CHANNELS SO THAT TONE SIGNALS THEREIN ARE HELD IN BALANCED RELATION, WITH EACH OF SAID CHANNELS HAVING A SELECTED FREQUENCYGAIN RESPONSE CHARACTERISTIC.