This is a inexpensive high fidelity (hi-fi) tone control circuit designed just with two low cost transistors as the active components. The schematic is one channel (mono) tone control, build the similar circuit will make it become stereo channel. This Hi-Fi tone control circuit can be operated with wide range supply voltage, 12V – 24V… Read More »
Here is the hum remover circuit diagram. “Hum” usually occured from live audio system, for example: input from microphone. Hum can be removed from an audio signal to get the maximum performance by mixing the actual hum with an antiphase hum in equal level. You can use any NPN transistor to support this circuit.
The above diagram is a basic Uninterupted Power Supply (UPS) circuit. This basic UPS circuit is a very simple and inexpensive. This circuit can be adapted/modified for other regulated and unregulated voltages by using different regulators and batteries. For a 15 Volt regulated supply, you may apply two 12V batteries connected in series (it will… Read More »