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.
In the figure we have a way of using a solar cell as a source for circuits with tunnel diodes. The solar...
This equalizer was found in the May 1978 issue of Radio Electronics magazine. The component values...
This circuit for high-impedance magnetic headphones was suggested as an experimental amplifier for hearing...