Hi Drazick, I agree with Ingo, you need a heavier supply than 200mA, 1,000mA upwards shopuld be fine. With a 200mA supply, it'll not only run a lot hotter (possibly even a fire risk if in unmonitored area such as a loft or roof space, but probably won't be able to power pre-amp optimally, and may not last very long before it cooks.