first differential amplifier means for generating a left right differential output signal which is {TAIL ~ a function} of the difference in {HEAD ~ amplitude} of said left and right output pulses 
first differential amplifier means for generating a left right differential output signal which is { TAIL ~ a function } of the difference in { HEAD ~ amplitude } of said left and right output pulses
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH