High Quality Circuit Design


The amplifier design technology from Yamaha is called ToP-ART which features an input to output with a direct symmetrical design. ToP-ART design and ART Base ensure optimum sound when processing and transmitting the audio signal. The signal is simple and direct, therefore it is less likely to be affected by noise and distortion. The left and right channels are organized in a straight, symmetrical layout for the highest signal purity. In addition, the ART (Anti-Resonance and Tough) Base bottom chassis and a solid center bar provide high rigidity support and dampers vibration. These design innovations contribute to this amplifier's rich audio reproduction with abundant musicality.


Outstanding Audio Performance


Notice the custom made power transformer, custom made block capacitors, two direct signal path speaker relays, one point grounding system, extruded aluminum heat sinks and other top quality parts to effortlessly handle demanding audio conditions. The quality of each individual part, as well as how they work together, basically determines the sound quality of this component. Yamaha uses only very high quality parts, carefully selected and tested for their sound properties.


Pure Direct Mode for Greater Sound Purity


The Pure Direct mode causes the audio signal to travel the shortest possible circuit route, bypassing the buffer amp, the tone, loudness and balance controls to virtually eliminate any signal degradation for the purest sound quality.


Continuously Variable Loudness Control


The A-S501 also features a new analog loudness control on the front panel that uses electronic volume for higher sound quality which lets you adjust the loudness effect as desired. Separate from the overall volume, this controls the balance of the low and high frequencies providing full tonal range at any volume level by compensating for the natural loss in the human ear at soft levels.