The circuit below is suggested by National Semiconductor in technical documentation on the LM3909. The circuit is powered by a single battery and has a very low consumption.
This TTL digital circuit from Texas Instruments documentation from the 1970s used the company's SN types...
This circuit was found in the December 1984 issue of Radio Electronics magazine. The circuit has a...
This circuit with bass and treble control and 10 W of power per channel is from the SGS manual of...