Monolithic integrated organ gate circuit

A parallel gate circuit apparatus for providing an audio tone across a common load resistor, said load resistor arranged to receive additional audio tones from additional parallel gate circuits upon receipt by said gate circuits of separate key signals for each tone, wherein said key signals can be simultaneously provided to undesirably cause an increased DC component to appear across said load resistor due to the total increase of current through said resistor upon activation of more than one key, and therefore upon activation of more than one parallel gate circuit, said gate circuit apparatus for eliminating said undesired DC component, comprising:

• a selectively activated audio tone circuit path in series with said load resistor and operative when activated to provide a tone current superimposed upon a predetermined DC current to cause said superimposed current to flow through said load resistor providing an output indicative of said audio tone,
• a selectively operated rest current circuit path in parallel with said tone circuit path and operative when activated to cause a rest DC current to flow through said load resistor,
• means for applying said key signal to both said tone circuit path and said rest current path to cause said tone circuit path to activate only during the presence of said key signal and to cause said rest current path to activate only during the absence of said key signal, to cause a controlled value DC current to always flow through said load resistor corresponding to the mean value of the total audio signal current flowing therethrough, whereby a plurality of such gate circuits arranged in parallel with each other can share said common load resistor without providing said undesirable DC component during multiple key signals.