This circuit that has a response from 10 Hz to 700 kHz was found in Philips documentation from 1968. Dual transistors can be replaced by matched pairs.
This circuit was taken from the 1974 Ferranti transistor manual. Note the shapes of the signals....
This mini siren, found in a 2003 publication, powers a small piezoelectric transducer, but a...
This fuzz effect is from a 1988 Italian publication, but it can be easily assembled, as the...