a second low pass filter coupled to said {HEAD ~ fourth signal} and having as an output {TAIL ~ a second filtered signal}, 
a second low pass filter coupled to said { HEAD ~ fourth signal } and having as an output { TAIL ~ a second filtered signal } ,
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH