Here is the circuit diagram of superb mini audio power amplifier, That can be power with 4.5 volt dc to 18 volts dc (maximum). This amplifier is based on TDA1015, Product of NXP Semiconductors ...

The debate still goes on as to which are better, valves or transistors. We don’t intend to get involved in that argument here. But if you can’t make your mind up, you should try out this simple ...

In a balanced op-amp circuit, the op-amp inputs see equal impedances looking into the circuit. Balanced circuits provide better performance by cancelling some input errors and have a simple R F /R I ...