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