If you wish to connect a low-cost, large-diaphragm microphone with decent sound quality to your PC you will often find that it requires a phantom power supply at a higher voltage than the PC can deliver. A ready-made phantom power supply with its own separate power brick or USB connection it is a bit too elaborate and expensive for applications such as Skype: you can build one yourself! What’s more, it can be made sufficiently small that it can be mounted directly inside a low-cost USB sound card.