Overview

The Yamaha A-S801 is a 100W/ch integrated amplifier announced in 2014, featuring a built-in 32-bit ESS SABRE ES9010K2M DAC supporting PCM up to 384kHz/32-bit and DSD128 (5.6MHz). It implements Yamaha’s proprietary ToP-ART (Total Purity Audio Reproduction Technology) design for optimized signal paths and anti-vibration chassis construction. Positioned as a mid-range model in the company’s traditional Hi-Fi product lineup, it offers 6 analog inputs including 1 phono (MM) input and 3 digital inputs. The unit features a robust 26.7-pound (12.1kg) chassis and incorporates a custom transformer with 12,000μF block capacitors.

Scientific Validity

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Evaluation based on measured data demonstrates good transparency but not fully reaching ideal levels. THD of 0.019% at rated output approaches transparent performance, while S/N ratio of 99dB (input shorted, 200mV) and 104dB (CD direct mode) are close but below the 105dB threshold for full transparency. Frequency response of 10Hz-100kHz +/-1.0dB provides extension beyond the audible range but exceeds the ±0.5dB ideal deviation. A damping factor of 240 achieves excellent speaker control capability. The built-in DAC’s THD+N of -106dB@1kHz and dynamic range of 116dB reach contemporary high-performance DAC standards. Channel deviation measurements of ±0.043dB via analog inputs and ±0.008dB via digital inputs demonstrate excellent results, providing scientifically audible improvement effects in some aspects but middle overall.

Technology Level

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The adoption of the ESS SABRE ES9010K2M DAC chip with PCM 384kHz/32-bit and DSD128 support represented advanced specifications for its time. The ToP-ART design featuring symmetrical amplifier layout and anti-vibration construction, combined with custom transformer and large-capacity block capacitors, constitutes a technically rational approach. However, the DAC chip is an off-the-shelf component, and the amplifier circuit fundamentally follows conventional Class AB design. From a 2025 perspective, higher-performance DAC chips and efficient Class D amplifier technologies have become commonplace, making the relative technology level standard. The degree of proprietary technology implementation is moderate, meeting industry standards but with limited breakthrough elements.

Cost-Performance

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The A-S801’s price of approximately 1000 USD represents high affordability among products with equivalent functionality and performance. Investigating competing products that meet specifications of 100W/ch output, built-in USB DAC, DSD 5.6MHz support, and PCM 384kHz/32-bit compatibility reveals higher pricing: Denon PMA-1700NE (approximately 2299 USD), Cambridge Audio CXA81 MkII (approximately 1199 USD), and Arcam A15 (approximately 1099 USD). While these products offer higher-performance DACs (PMA-1700NE supports DSD 11.2MHz) and additional features, no market alternatives exist at lower prices for the basic equivalent functionality of 100W output with DSD-compatible built-in DAC. Therefore, cost-performance achieves the maximum rating of 1.0.

Reliability & Support

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As a Yamaha brand product, it maintains industry-standard reliability. The 1-year manufacturer warranty and domestic authorized dealer support system represent typical standards. With sufficient market track record as a 2014 product release, no significant quality issues have been reported. However, compared to emerging manufacturers, it lacks particularly superior support systems or extended warranties, representing average industry response. Parts supply and after-sales service maintain stability as a major manufacturer, but advanced support such as recent firmware update compatibility is not specifically provided. Overall, it maintains standard reliability and support levels.

Rationality of Design Philosophy

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The approach of ensuring versatility through both analog and digital compatibility and achieving near-transparent measurement performance is rational. Implementing stable operation through Class AB amplifier circuits and toroidal transformer adoption is also technically valid. Particularly noteworthy is achieving 100W output with built-in USB DAC and DSD support in the same price range, providing functionality that other manufacturers offer at higher prices - an extremely rational design philosophy. General-purpose equipment (smartphone + external DAC/amplifier) would require multiple devices to achieve equivalent output and DSD support, making dedicated equipment superiority clear in terms of total cost, installation space, and operability. The design philosophy of democratizing high performance through price-disrupting approaches deserves maximum evaluation from a contemporary rationality perspective.

Advice

The A-S801 is an integrated amplifier with exceptional cost-performance that achieves high affordability among products with 100W/ch output, built-in USB DAC, and DSD support specifications. While competing products with equivalent functionality sell at higher prices, the pricing around 1000 USD can be considered competitive. The built-in DSD-compatible USB DAC enables high-quality playback from computers without requiring separate DAC purchases. Measurement performance also approaches transparent levels with technically valid design. The 100W output enables driving medium to large speakers with versatility for long-term use. With no alternatives offering equivalent functionality at lower prices currently available, the A-S801 can be recommended as a cost-performance superior choice.

(2025.8.5)