Transistors Q5 and {HEAD ~ Q5A} form {TAIL ~ a phase splitter circuit} which controls switching of the drain line transistors Q9, Q10, Q9A and Q10A to establish the push pull operation of the driver as is well understood in the art and need not be further discussed herein 
form
Transistors Q5 and { HEAD ~ Q5A } form { TAIL ~ a phase splitter circuit } which controls switching of the drain line transistors Q9 , Q10 , Q9A and Q10A to establish the push pull operation of the driver as is well understood in the art and need not be further discussed herein
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH