Found in a 1967 Electronics World, this preamplifier uses an integrated circuit from that time, difficult to obtain today. The maximum frequency is 15 kHz.
This filter was found in Texas Instruments documentation from the 1980s. The circuit uses a common...
This circuit was found in an old documentation, being able to generate signals of frequencies in...
Found in a 70s documentation, this amplifier employs an uncommon operating system today. The power...