The circuit can be modified to include {HEAD ~ a multiplication unit} for multiplying the input signal, the first delayed signal or {TAIL ~ the output signal} by a predetermined constant to obtain a desired direct current gain 
for multiplying
The circuit can be modified to include { HEAD ~ a multiplication unit } for multiplying the input signal , the first delayed signal or { TAIL ~ the output signal } by a predetermined constant to obtain a desired direct current gain
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH