a plurality of {HEAD ~ level control units} receiving {TAIL ~ said modified signals} and providing normalized modified signals having a constant amplitude 
receiving
a plurality of { HEAD ~ level control units } receiving { TAIL ~ said modified signals } and providing normalized modified signals having a constant amplitude
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH