The circuit is from a Radio Electronics magazine from October 1987. The Triac must be equipped with a heatsink and the transistors are general purpose.
This 9 W amplifier with transistors from the 60's was found in documentation of the time. The...
The purpose of this 1965 Radio Electronics circuit is to observe cycloid waveforms on a standard...
In this circuit found in the December 1972 Radio Electronics magazine. R can be from 1k to 22k,...