Overview

The TEAC AP-505 is a compact stereo power amplifier that employs a TEAC-tuned Hypex Ncore module. Rated output: 70W + 70W (8Ω, 1kHz, THD 0.8%) and 125W + 125W (4Ω, 1kHz, THD 0.8%). Maximum (JEITA): 95W + 95W into 8Ω and 170W + 170W into 4Ω. In BTL it is specified at 230W (8Ω, THD 0.8%) rated and 350W (8Ω, JEITA) maximum. It supports Stereo, Bi-amp, and BTL modes, uses a fully-balanced circuit from input to output, and includes TEAC’s “Pin-Point” feet for vibration control [1][2][3].

Scientific Validity

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We found no independent lab measurements for the AP-505. Manufacturer specs list THD 0.0015% (8Ω, 1kHz, 12.5W, JEITA), S/N 113 dB (8Ω, 1kHz, IHF-A), frequency response 10 Hz–50 kHz (+0/−5 dB @1 W), and damping factor ≥370 (JEITA) [1][2]. These numbers suggest transparency in normal use, but they are limited to 1 kHz and low power and are not third-party verified. Moreover, sub-USD 100 amps have demonstrated similar “transparent-class” distortion/noise in third-party tests (e.g., Fosi Audio V3 stereo: SINAD around ~90 dB at 5 W; AIYIMA A07 TPA3255 also measures clean at typical listening levels) [4][5]. Given the reliance on manufacturer data and the availability of budget gear with solid lab results, we set scientific validity at 0.6 (baseline 0.5, +0.1 for detailed JEITA/IHF-A disclosures).

Technology Level

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The AP-505 leverages proven Ncore technology in a fully balanced architecture with a toroidal PSU and compact chassis. However, it predates the latest NCOREx/NCx generation now used by rivals and does not push the current state of the art in distortion or power. Execution is solid but not cutting-edge [3][6].

Cost-Performance

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Current store price shows 1,999 USD regular (often on sale at ~1,499.88 USD) [7]. A finished stereo power amplifier with balanced inputs and equal-or-better published/measured performance that is cheaper is the Buckeye Amps Hypex NCx500 (2-channel) at 1,050 USD; it offers vastly higher power (manufacturer: ~380 W/8Ω, 700 W/4Ω per channel at 1% THD) and extremely low distortion/noise typical of NCOREx modules [6].
CP calculation (cheapest equal-or-better vs. target): 1,050 USD ÷ 1,999 USD = 0.53 → 0.5.

Reliability & Support

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Standard warranty/support and a fanless design (no moving-part failures) are positives. No field reliability statistics or extended program are published. Overall, typical for the category [7].

Rationality of Design Philosophy

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A compact, fully balanced Ncore implementation aimed at transparency is coherent and practical. In 2025, however, newer NCx-based designs deliver more performance per dollar, so the approach is rational but no longer class-leading [1][3][6].

Advice

If you value TEAC’s compact form factor, build, and styling, the AP-505 is a tidy way to get a balanced Ncore power stage. If your priority is measured performance per dollar, NCx-based stereo power amps (e.g., Buckeye NCx500) offer clearly superior on-paper performance at a much lower price [6][7]. For pure transparency at very low cost, budget class-D options like Fosi V3/A07 already measure cleanly at typical powers [4][5].

References

[1] TEAC AP-505 Owner’s Manual (Specifications). Rated power, JEITA maxima; THD 0.0015% (8Ω, 1kHz, 12.5W); S/N 113 dB; FR 10–50 kHz (+0/−5 dB). https://teac.jp/downloads/products/teac/ap-505/ap-505_om_efs_va.pdf
[2] TEAC (International) – AP-505 Specifications/Overview. Balanced design; damping factor ≥370 (JEITA). https://teac.jp/int/product/ap-505/spec , https://teac.jp/int/product/ap-505/top
[3] TEAC (International) – AP-505 Features. Fully balanced from input to output. https://teac.jp/int/product/ap-505/top
[4] Audio Science Review – Fosi Audio V3 (stereo) measurement thread. https://www.audiosciencereview.com/forum/index.php?threads/fosi-audio-v3-amplifier-review.45757/ ; summary with figures: https://www.audiophonics.fr/en/blog-diy-audio/67-fosi-audio-v3-review-by-audiosciencereview.html
[5] Audio Science Review – AIYIMA A07 (TPA3255) measurement thread. https://www.audiosciencereview.com/forum/index.php?threads/aiyima-a07-tpa3255-review-amplifier.18984/
[6] Buckeye Amps – Hypex NCx500 2-Channel (price/specs; NCx generation). https://www.buckeyeamp.com/shop/amplifiers/hypex/ncx500/2_channel
[7] TEAC USA Store – AP-505B (regular price ~1,999 USD; frequent sale). https://teacusa.com/products/ap-505b-stereo-ampifier

(2025.8.15)