[Amps] solid state

[carl seyersdahl]

      I hope this isn't too far off base. Some amps have transistors and
microcircuits in them.!!
      Can anyone out there tell me when , (more or less)
   microcircuits became reliable enough to use in hi accuracy test
equipment.??? I'm trying to put a time frame on a piece of test equipment ,
and the company that made
it. (an impedance bridge) small, portable, battery operated, with
transistors and microcircuits in it.!!
  please reply off list , and thanks for the bandwidth.!!
       carl / kz5ca