This sensitive 5-band circuit was found in a September 1995 issue of Electronics Now magazine. The headphones, for greater sensitivity, should be high impedance.
This indicator or VU meter for stereo amplifiers was found in a 90s Radio Electronics. The...
This interesting circuit from 1967 documentation uses three series lamps to regulate the voltage...
This circuit causes an instrument needle to oscillate to signal an event. The circuit is powered by...