Overview

The Luxman P-750U Mark II is the company’s flagship headphone amplifier announced in 2021. It incorporates evolved circuit technology developed over four years since the original P-750U release, featuring ODNF-u (Only Distortion Negative Feedback-ultimate) technology. The unit delivers high output power of 8W+8W/16Ω balanced and 4W+4W/8Ω unbalanced, equipped with diverse connection terminals including 4-pin XLR balanced output. Housed in a large 13.3kg chassis with 42W power consumption, the design pursues high sound quality through substantial material investment, including high-purity 6N conductors in the main signal path.

Scientific Validity

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The measurement performance is strong in several areas, achieving THD+N 0.0005-0.009% (20Hz-20kHz), frequency response of 20Hz-20kHz (+0, -0.1dB) and 10Hz-170kHz (+0, -3.0dB), output impedance below 500mΩ, channel separation exceeding 90dB, and channel balance within 0.05dB across 70dB dynamic range. These metrics generally reach transparency levels. However, the S/N ratio of 95.3dB (A-weighted) falls short of the 105dB transparency threshold, placing it in an intermediate range. While competitive products achieve world-class measurements across all parameters, this results in a relative deduction.

Technology Level

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The ODNF-u technology has evolved from conventional ODNF, improving distortion characteristics by enhancing sub-amplifier error detection accuracy. Technical completeness is high-level, including adoption of high-purity 6N conductors, four-stage gain settings, and fully balanced circuit design. However, the basic circuit approach remains an extension of conventional technology with limited innovative technical elements. While performance improvements through substantial material investment are confirmed, technical advantages are relatively limited compared to modern approaches that achieve equivalent measurement performance more efficiently.

Cost-Performance

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Against the current market price of 2310 USD, the SMSL SH-9 (approximately 267 USD) exists with equivalent or superior functionality and measurement performance, including balanced output, high power (6W/16Ω), THD+N below 0.0001%, and SNR above 130dB. 267 USD ÷ 2310 USD = 0.12, indicating very low cost-performance. Products achieving equivalent or superior performance at about one-tenth the price exist in the market for key functions including balanced output, high power output, and low distortion, presenting significant price competitiveness challenges. Excluding chassis and internal wiring quality feel and brand value, pure acoustic performance-to-price ratio is significantly disadvantaged.

Reliability & Support

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Luxman, established in 1925 as a long-standing audio manufacturer, has established reliability within the industry. The 3-year warranty period and nationwide authorized service network repair system are at industry standard levels. However, specific data regarding failure rates and long-term reliability is limited, with no confirmed special advantages compared to high-performance products from emerging manufacturers. As a pure analog design requiring no firmware updates, software-related issues do not occur, but functional expansion through updates cannot be expected.

Rationality of Design Philosophy

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While the direction of achieving transparency levels in most measurement standards is rational, the traditional design philosophy of large chassis and high pricing raises questions when modern approaches exist that achieve superior performance at far lower cost. Evolution of ODNF technology is commendable, but the fundamental circuit approach remains an extension of traditional methods continuing from the 1970s. Although claiming sound quality improvements through high-purity conductors and substantial material investment, the existence of products achieving better measurement results at significantly lower prices presents major challenges to the economic rationality of the design philosophy. While the pursuit of scientifically meaningful improvements is appreciable, it represents a highly inefficient design.

Advice

The P-750U Mark II achieves solid measurement performance in key areas and will provide satisfaction for users prioritizing acoustic transparency despite the SNR limitation. However, for those seeking pure acoustic performance, alternative products like the SMSL SH-9 achieving equivalent or superior measurement results at about one-tenth the price are strongly recommended. This product is limited to users who find special value in Luxman brand worth, Japanese-made reliability, and luxurious chassis design, and can tolerate the substantial price difference. Those prioritizing only objective acoustic performance should recognize that multiple more rational choices exist. While suitable for users with ample budget seeking comprehensive satisfaction including brand value, it cannot be recommended for users prioritizing cost-performance.

(2025.8.4)