In the figure we have the basic configuration of an operational amplifier for audio signals. The circuit is from a Radio Electronics from the 90s. The power supply must be symmetrical.
This circuit was obtained from an English magazine from 1976. The circuit operates two LEDs and...
Found in a publication from the 60's, this power supply has no regulation, but only current...
This circuit can use the LM148 and its more modern equivalents, generating a sinusoidal signal whose...