ToP-ART, stereo power and connections for analogue and digital sources
A-S501 is a Yamaha integrated amplifier combining ToP-ART construction with analogue and digital inputs, continuous loudness control and management of two pairs of speakers.
The design is built around a direct and symmetrical signal path, with power supply and components selected to maintain low impedance and limit noise and vibration. A-S501 can therefore become the centre of a stereo system with traditional sources, a television, digital player, turntable and subwoofer.
Key features
- ToP-ART with direct symmetrical I/O layout and anti-resonance ART base.
- 85 W + 85 W RMS into 8 ohms and a European maximum power output of 120 W + 120 W.
- Dedicated transformer, 12,000 µF capacitors and extruded aluminium heat sinks.
- Pure Direct bypasses unnecessary circuits when the most direct signal path is desired.
- Continuous loudness control separate from the main volume control.
- Optical and coaxial inputs for digital sources, subwoofer output and MM phono input.
- Speaker selection A, B or A+B and connection for two pairs.
- Aluminium front panel, selected gold-plated speaker terminals and RCA connections, plus automatic standby.
ToP-ART and symmetrical construction
ToP-ART, short for Total Purity Audio Reproduction Technology, arranges the left and right channels in a direct and symmetrical layout. The shorter path reduces the opportunities for noise or distortion to affect the signal, while the ART base and reinforcing structure limit vibrations transferred to the circuitry.
Power supply and components
The power supply uses a dedicated transformer, 12,000 µF capacitors and extruded aluminium heat sinks. Yamaha selects components according to how they behave within the complete circuit, so current reserve and mechanical stability work together with the amplifier topology during dynamic passages and at low frequencies.
Power and speaker control
The output stage delivers 85 W + 85 W RMS into 8 ohms, with 120 W + 120 W stated as the European maximum output. Terminals are provided for two pairs of speakers, selectable as A, B or A+B, together with a dedicated subwoofer output, allowing the system to use a second pair or active low-frequency reinforcement.
Pure Direct and volume management
Pure Direct bypasses unnecessary circuits when the most direct signal path is desired. The analogue loudness control is separate from the main volume control and compensates for the ear's different sensitivity to low and high frequencies at reduced listening levels, without requiring constant changes to the normal tone controls.
Digital inputs, phono and subwoofer
The optical and coaxial inputs allow direct connection of televisions, players and other digital sources, keeping the signal in the digital domain until internal conversion. The MM phono input handles a turntable with a compatible cartridge, while the subwoofer output allows an active subwoofer to be added to the stereo system.
