Overview

The E-4000 is Accuphase’s 12th-generation Class-AB integrated amplifier succeeding the E-480. It uses a four-fold parallel push-pull output stage (180 W/8 Ω, 260 W/4 Ω), an instrumentation-amplifier signal path, and Accuphase’s AAVA volume control now enhanced with ANCC (noise/distortion cancelling) for lower noise. Key specs include damping factor 800, FR up to 3–150 kHz at 1 W, and MAIN IN S/N 125 dB. [1]

Scientific Validity

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On audibility-relevant metrics the E-4000 is close to the transparent threshold: THD is 0.05% (20 Hz–20 kHz, both channels, 4–16 Ω), IMD 0.01%, damping factor 800, and MAIN IN S/N 125 dB (A-wtd). Frequency response reaches 20 Hz–20 kHz within −0.5/−0.2 dB (input/main-in) and 3–150 kHz at 1 W. The THD figure is above the 0.01% “ideal” line but below clearly problematic levels, so transparency is borderline but broadly achieved in practice. [1]

Technology Level

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Engineering is sophisticated: AAVA with ANCC reduces noise at low-to-mid volume, the entire gain structure is instrumentation-amplifier based with balanced remote sensing, and the PSU uses a large toroidal transformer with 40,000 μF filtering per channel bank. These are rational, internally consistent design choices, although the overall topology remains conventional Class-AB rather than a breakthrough architecture. [1]

Cost-Performance

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Using the cheapest equal-or-better alternative as required, the NAD C 399 provides the same continuous power (180 W/ch into 8/4 Ω), lower wideband THD (<0.02% from 250 mW to 180 W), damping factor >150 (above the audibility threshold), and fully integrated DAC/HDMI eARC/BT. This satisfies equivalence from the user’s standpoint (functions + measured performance). US market prices on the review date: C 399 2,799 USD [3], E-4000 13,575 USD [4].
2,799 USD ÷ 13,575 USD = 0.206 → CP 0.2 (rounded). [2][3][4]

Reliability & Support

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Accuphase sells via authorized distributors with dedicated after-sales service channels; official support is routed through local distributors/authorized service stations. Long product cycles and robust construction suggest low field stress, but public warranty duration and fleet failure statistics are not centrally published, so we cap the score. [5][6]

Rationality of Design Philosophy

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The company’s focus on measurable noise/distortion reduction (AAVA+ANCC), balanced remote sensing, and strong PSU engineering is scientifically rational and maps to metrics that matter. The sticking point is pricing: measurable advantages over objectively transparent competitors are modest relative to the large premium. [1][2]

Advice

If you want a meticulously built analog integrated and value Accuphase’s industrial design and ergonomics, the E-4000 will deliver near-transparent performance. For buyers optimizing rational value, the NAD C 399 (~2,799 USD) is the cheapest objectively equivalent pick; if you want more headroom with modern conveniences, the Rotel RA-1592MKII (200 W/8 Ω, ~3,699 USD) is another strong option still far below the E-4000’s price. [2][3][7][4]

References

[1] Accuphase Laboratory Inc., “E-4000 Catalog (EN),” https://www.accuphase.com/cat/e-4000_e.pdf, accessed 2025-08-20.
[2] NAD Electronics, “C 399 Data Sheet (12-22-2023),” https://nadelectronics.in/wp-content/uploads/2023/12/C-399-data-sheet-1.pdf, accessed 2025-08-20.
[3] Crutchfield, “NAD C 399 Integrated amp with DAC and Bluetooth,” https://www.crutchfield.com/p_745C399/NAD-C-399.html, accessed 2025-08-20.
[4] A&B TV (Authorized Dealer), “Accuphase E-4000 2 Channel Integrated Stereo Amplifier,” https://www.abtvaustin.com/product/accuphase-e-4000-2-channel-integrated-stereo-amplifier-e-4000-1348298, accessed 2025-08-20.
[5] Accuphase Laboratory Inc., “Support,” https://www.accuphase.com/support.html, accessed 2025-08-20.
[6] Accuphase Laboratory Inc., “Distributor list,” https://www.accuphase.com/distributor.html, accessed 2025-08-20.
[7] Crutchfield, “Rotel RA-1592 MKII (Black),” https://www.crutchfield.com/p_440A15922B/Rotel-RA-1592-MKII-Black.html, accessed 2025-08-20.

(2025.8.21)