Using an operational amplifier of the time, this circuit was obtained from a 90s Radio Electronics. The circuit covers the frequency range from 2 Hz to 20 kHz.
This gain 10 CMOS op amp was found in the May 1993 issue of Electronics Now magazine. It is...
This circuit was found in a 1991’s PE Hobbyst Handbook. The circuit is based on altering the sound...
This circuit was found in a 1977 publication, but it can be easily assembled, although unijunction...