This mixer with 20 dB gain per channel uses RCA's CA3048 integrated circuits. We found it in the July 1971 Radio Electronics magazine. The power supply does not need to be symmetrical.
The figure shows three circuits for using headphones in amplifiers with speakers that do not have...
In this charger, the charging current is basically limited by the LEDs. The transformer is a low...
This configuration is from an old integrated circuit manual. The circuit can be applied to modern...