This is a combined circuit of tone generator and preamplifier. We found it in a 1975 documentation. Operational amplifiers of that time can be replaced by modern equivalents.
In this circuit we show how to configure the LM3914 as a bargraph or moving point, supplying 10...
We found this circuit in a documentation for 1977 American radio amateurs. The LM336 integrated circuit...
This modulator circuit is nothing more than an audio amplifier that serves to modulate amplitude...