Bias for transistor 168 is provided by current via {HEAD ~ return resistor} 174 coupled between the base thereof and {TAIL ~ the voltage source A} 
Bias for transistor 168 is provided by current via { HEAD ~ return resistor } 174 coupled between the base thereof and { TAIL ~ the voltage source A }
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL