ToP-ART design and ART base ensure optimum sound when processing and transmission of the audio signal is simple and direct there is less chance of it being affected by noise and distortion. Yamaha's amplifier design technology called ToP-ART features an I/O (input to output) direct symmetrical design, with left and right channels organized in a straight, symmetrical layout for highest signal purity. In addition, the ART (Anti-Resonance and Tough) base bottom chassis and a solid centre bar provide high-rigidity support and vibration damping. These Yamaha design innovations contribute to this amplifiers' rich audio reproduction with abundant musicality. Custom-made power transformer, custom-made block capacitors, two direct signal path speaker relays, one-point grounding system, aluminium-extruded heat sinks and other top-quality parts effortlessly handle demanding audio signal conditions. The quality of each individual part, as well as how they work together, basically determines the sound quality of any component. Yamaha uses only very high quality parts, carefully selected and tested. Yamaha has a high reputation for Hi-Fi components. The A-S501 is created by taking advantage of this rich experience and high technological expertise. Based on the concept of "Natural Sound", for reproducing all music as it really sounds, and built with scrupulous care from circuit design to basic sound production, even though an entry model it reproduces high sound quality and musically rich sound.