This direct coupled amplifier using 3 transistors and low voltage power was found in the April 1961 Radio Electronics magazine.
This circuit was found in a 1969 Mullard publication. The transistor may be the modern equivalent...
This circuit uses an operational like to the 741 having been found in a 2001 documentation. The...
Found in English documentation, this timer produces an audio signal at the end of the timing. The...