This polarity inverter circuit for voltages down to about -12 V was found in the December 1992 issue of Radio Electronics magazine. The current is a few mA.
This preamplifier for magnetic cartridges was found in the February 1990 issue of Radio...
We find this circuit in an American manual from the 80's. The circuit can be implemented with more...
September 2016 - It can be obtained from Mouser Electronics the new integrated circuit µCC21520...