Two track reproducing system with two recorded levels utilizing a variable impedance element

Claim 1

IN COMBINATION IN A SYSTEM FOR REPRODUCING INFORMATION CONTAINED ON A RECORDING MEDIUM WITH THE INFORMATION RECORDED ON THE MEDIUM AT A PLURALITY OF RECORDING LEVELS, FIRST MEANS OPERATIVELY COUPLED IN THE RECORDING MEDIUM AND RESPONSIVE TO A FIRST LEVEL OF THE IMFORMATION FOR PRODUCING A FIRST SIGNAL HAVING CHARACTERISTICS IN ACCORDANCE WITH THE INFORMATION, SECOND MEANS OPERATIVELY COUPLED TO THE RECORDING MEDIUM AND RESPONSIVE TO A SECOND LEVEL OF THE INFORMATION FOR PRODUCING A SECOND SIGNAL HAVING CHARACTERISTICS IN ACCORDANCE WITH THE INFORMATION, THIRD AND FOURTH MEANS EACH CONSTITUTING IMPEDANCE MEANS AND HAVING FIRST AND SECOND TERMINALS WITH THE FIRST TERMINALS OF THE THIRD AND FOURTH IMPEDANCE MEANS COUPLED TOGETHER AT A COMMON JUNCTION AND WITH THE SECOND TERMINALS OF THE THIRD AND FOURTH IMPEDANCE MEANS OPERATIVELY COUPLED TO THE FIRST AND SECOND MEANS RESPECTIVELY TO PROVIDE AN OUTPUT SIGNAL AT THE COMMON JUNCTION COMPOSED OF THE FIRST AND SECOND SIGNALS, THE THIRD IMPEDANCE MEANS BEING VARIABLE BETWEEN A FIRST VALUE AND A SECOND RELATIVELY HIGHER VALUE AND THE FOURTH IMPEDANCE MEANS BEING FIXED AT A VALUE INTERMEDIATE THE FIRST AND SECOND VALUES OF THE THIRD VARIABLE IMPEDANCE MEANS, AND MEANS OPERATIVELY COUPLED TO THE THIRD IMPEDANCE MEANS FOR VARYING THE THIRD IMPEDANCE MEANS BETWEEN THE FIRST AND SECOND VALUES TO CHANGE THE RELATIVE PROPORTIONS OF THE FIRST AND SECOND SIGNALS WHICH FORM THE OUTPUT SIGNAL IN ACCORDANCE WITH THE VARIATION OF THE THIRD IMPEDANCE MEANS.