Found in na 1970 EDN this circuit has a parallel regulation providing a symmetrical output of 15 V. The transistors are from that time.
The figure shows how to measure current with a 3 ½ digit 7107 meter described in Electronics Now...
I found this electronic organ in magazine published in 1976 from my vast collection of foreign...
The presented circuit uses the National Semiconductor's LM3909, an oscillator that operates with...