This circuit for multiple sound inputs was found in a Radio Electronics from January 1992. It consists of a Bargraph connected to a multi-input mixer.
This circuit generates noise pulses for audio equipment probes. The circuit is from a 90’s 303...
This modulated light transmitter was found in a 90s Popular Electronics. In place of the lamp with...
This circuit, found in a 1958 magazine, is for reference only, since the components are not easy...