Warranty periods typically range from one to five years. Longer warranties may give you peace of mind, but find out what will and won't be covered. Many warranties only cover manufacturing defects. Since warranty repairs are often made at the manufacturer's discretion, be sure to explain fully and cordially the circumstances of the product failure. Cooling and ventilation.
Most amplifiers dissipate heat through the use of small fans installed in the unit.
If fan noise may present problems for you, look for the quietest fan you can. When buying multiple amplifiers, be sure that they all move air in the same direction for maximum heat dissipation. More watts doesn't mean better sound. A high wattage output has nothing to do with sound quality. Take the time to listen carefully to music and voice reproduction, both taped and live.