This circuit was found in a documentation from 1948. There are 5 valves with push-pull output. The source uses a transformer, and the indicated application is with turntables.
This 9 V amplifier has a gain of 20 and provides a power of a few hundred milliwatts. The circuit is...
This circuit, suggested by Texas Instruments, uses a TIS43 or 2N2646 to produce short light pules. The...
Powered by just 1.5 V this 80's amplifier uses an integrated circuit of the era. The circuit is...