Found in Mallory documentation from 1968 this circuit uses an integrated circuit from that time. The circuit has a flat response from 10 Hz to 700 kHz.
This circuit was found in Motorola documentation from 1966. The lamps are according to power and...
This circuit, which uses components still common today, was found in a 1997 documentation. It...
This circuit is intended to apply the music signal from a stereo to a telephone line for the...