Found in an Electronics World of 1966, this circuit makes use of FETs of the time. Modern equivalents can be used. The high voltage supply suggests its use with tube amplifiers.
This circuit was found in a QST from the 1990s. The circuit expands the scale of a 10V instrument to...
This 8 ohm output amplifier was found in a 1968 Motorola publication. The circuit uses transistors...
This general-purpose preamp configuration was found in the 1960 Mullard transistor reference...