This high-impedance headphone circuit was found in a 1990s William Sheets. The power is low, but the high input impedance makes it useful for radio applications.
The integrated circuit used in this stereo preamp is uncommon today, but the circuit can be...
This circuit was found in a 1967 General Electric manual. It is intended for the control of high...
Carbon microphones are no longer used in most projects. However, finding one in the scrap metal, it...