This boost amplifier was found in a Popular Electroniics from the 90s. The circuit operates up to 20 MHz depending on the coils used.
This amplifier has a few Watt output, using old transistors. The speaker is 45 ohms, but with...
This circuit is from an old American documentation, from 1977, but it can be implemented with more...
This circuit was obtained from the CA3140 datasheet. This component consists of an operational amplifier...