These basic bass controls were obtained from an article in Electronics Now magazine in February 1995. They are basic passive circuits in (a) basic tone, (b) boost, (c) cut, and (d) flat response.
The sensor for this circuit found in a 1980 publication is a common LED. The LED can sense both...
This circuit was originally designed for the practice of Morse code, something common in 1966, the year...
This circuit uses a diode as a radiation sensor. The operational ones are old because the...