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.
In the figure we have the way to connect two high power operational amplifiers LM12 to double the...
This circuit uses the Linear Technology LT6505 and was found in a 2005 manual. The circuit is for 24 V...
a This circuit was obtained from a 1978 Practical Wireless. It causes a low-power 1.5V lamp to...