The black Yamaha A-S3000 Integrated Amplifier has a highly rigid double structure construction in order to achieve pure and accurate audio amplification. The bottom chassis and insulator ward off external vibration, and provide each circuit board a floating structure supported by an independent inner frame, thoroughly eliminating the impact of vibration. And the power source unit, which consists of a power transformer and capacitors, which are major sources of internal vibration, is fixed firmly with a three-dimensional structured inner frame, and is supported solidly by the front panel and the rear panel. The power amp circuit board and the weighty heat sink are attached to the left and right inner frames. The power supply unit and amplifier circuits are thus structurally isolated, achieving an ideal chassis structure which thoroughly blocks the transmission of vibration. Moreover, the inner frame that supports the power transformer is shaped with ample space below it, allowing passage of the wiring to each circuit over the shortest possible route. The chassis helps to minimize the length of the signal paths and achieve low impedance, as well as providing high rigidity and anti-vibration benefits. The result is a dramatic reduction in signal loss, for remarkably pure audio amplification.