This circuit works as both an injector and a signal follower. We found it in the May 1994 issue of Electronics Now. The Z1 headphone must be high impedance.
This power supply is protected from shorts in the load. The BD135 must be mounted on a heatsink...
This circuit appears in various parts of this site and this section, with diverse origins. This is from...
This powerful amplifier with output in complementary symmetry is from an old documentation....