This circuit has a gain of 6 dB for low frequencies from 85 Hz and can be used in a mini subwoofer. The circuit is from a Radio Electronics from March 1990.
Found in an English Maplin documentation from 1983, this circuit generates separate frequency...
This circuit uses a piezoelectric transducer to produce sounds like a buzzer. Frequency is...
Guitar preamp (CB22146E) Found in an English publication from 1989, this circuit uses a still...