Suggested by Amperex in 1968, this circuit is intended for hearing aids. The integrated circuit used, a TAA370 is not common today.
Found in a 1980s documentation, this amplifier uses an integrated circuit of the era. The RLC...
This interesting experimental and didactic configuration was found in a 1977 Radio Shack...
This circuit for a frequency of 40 kHz was found in an old Electronic Design. There were no...