This amplifier was found in a 1970s documentation. Darlington transistors can be replaced for modern equivalents of at least 80 V x 2 A, equipped with good heat sinks.
This simple 3-channel passive mixer can be used with low-intensity signal sources but requires...
This sound effects circuit is based on 555 rectangular oscillating circuits but produces...
This circuit is from a commercial receiver for air conditioning control published in Radio...