Found in a 1990s Popular Electronics, this circuit uses two transistors to boost the power of a 741 with audio signals. The power depends on the transistors used, which can be general-purpose types.
The cut-off frequency of the filter shown in the figure can be adjusted to values between...
This circuit was found in a Popular Electronics from the 90s. The components used are all common...
This circuit uses a dual floodgate MOSFET not very easy to obtain today. Its handling is very...