This 6-tube two-channel amplifier was found in an American documentation from 1947. The circuit is two-channel with a separation of bass and treble.
Found in ancient American documentation, this circuit uses some components from the time, such as...
In the figure we have the way to compensate an operational amplifier. The circuit is valid for...
With this circuit, it is possible to excite a white LED or another type of high brightness with...