Overview

The sixth-generation MC275 is a 2-channel vacuum-tube power amplifier rated at 75W per channel into 4/8/16Ω (150W mono parallel). McIntosh’s Unity Coupled output transformers, Sentry Monitor protection, and polished stainless chassis remain the defining features. Manufacturer specs cite 0.5% THD, 105dB S/N (at rated output), and damping factor >22; third-party lab work confirms wide bandwidth and comparatively low source impedance for a tube design, but performance remains well short of modern transparent solid-state amplifiers [1][2].

Scientific Validity

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Third-party measurements show unusually wide bandwidth (–3dB ≈ 91kHz) and small FR interaction with a simulated speaker (≈±0.5dB from the 8Ω tap). However, THD+N stays well above transparent thresholds: ≈0.05–0.1% at modest levels depending on tap/load, and up to the 0.5% spec near rated power. A-weighted S/N at 1W was about 100–101dB, below the 105dB “transparent” yardstick; channel separation exceeded 90dB. Damping factor is specification >22 (order-of-magnitude below modern high-feedback designs). Net-net: good for a transformer-coupled tube amp, but not transparent by strict modern criteria [1][2][4].

Technology Level

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In-house transformer design (Unity Coupled), robust safety/connection systems (Sentry Monitor, Solid Cinch), and long accumulated know-how support a respectable technology score. That said, the approach is mature analog with limited digital/software integration or novel control techniques today [1].

Cost-Performance

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Current US street price for MC275 VI is 7,500 USD [3]. The cheapest finished product we can identify that is equal-or-better in user-visible functions and measured performance is TOPPING PA7: 2-channel power amp with balanced and unbalanced inputs; measured/quoted THD+N down to 0.0003% at 8Ω/20W (balanced), SNR up to 127dB, and 135W×2 into 8Ω at <1% THD+N (far higher clean output than MC275). Price: 296.65 USD [6].
Calculation (policy formula, single comparator):
296.65 USD ÷ 7,500 USD = 0.0396 ⇒ 0.0 (rounded to one decimal).
Equivalence note: same core function (stereo power amplification), with lower distortion and higher SNR/output power on the comparator [6].

Reliability & Support

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McIntosh provides a 3-year limited warranty (tubes 90 days) via authorized dealers and service agencies; historically, the brand maintains serviceability and parts for many years. The tube output stage is inherently consumable/heat-stressed versus solid-state, moderating the score. Net result: slightly above average support and history with tube-amp caveats [1][8].

Rationality of Design Philosophy

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Prioritizing vacuum tubes and large output transformers is a conservative, heritage-driven choice that predictably trades measurable fidelity (THD+N, damping factor) for a particular operating philosophy and industrial design. Costs concentrate on non-performance-critical factors (materials/finish/transformers) rather than improvements to measurable audibility; as such, the direction is scientifically irrational relative to transparent-first design goals.

Advice

Buy MC275 VI only if you specifically want a premium tube amplifier with McIntosh aesthetics, build, and dealer ecosystem. For audibly transparent amplification at a fraction of the price and with far lower distortion/noise, choose a modern solid-state power amp like TOPPING PA7 (desktop/stereo systems) [6]. If you need very high continuous power for difficult speakers, consider a high-power solid-state unit such as Emotiva XPA-DR2 (balanced inputs, 550W/8Ω per ch claimed; check latest pricing/availability) [10].

References

[1] McIntosh, “MC275 2-Channel Vacuum Tube Amplifier.” https://www.mcintoshlabs.com/products/amplifiers/MC275B (accessed 2025-08-28). Key specs and downloads.
[2] Stereophile (J. Atkinson), “McIntosh MC275 power amplifier—Measurements.” https://www.stereophile.com/content/mcintosh-mc275-power-amplifier-measurements (accessed 2025-08-28). Lab results incl. FR, THD+N, output Z, S/N.
[3] Paragon Sight & Sound, “McIntosh MC275 VI Stereo Amplifier – In-Store Only.” https://www.paragonsns.com/products/mcintosh-mc275-vi-2-channel-tube-power-amplifier (accessed 2025-08-28). US price 7,500 USD.
[4] Electori (JA), “MC275VI.” https://www.electori.co.jp/mcintosh/mc275vi.html (accessed 2025-08-28). JP specs and MSRP 1,540,000円.
[5] PhileWeb (JA), “エレクトリ、McIntosh製品の価格改定を7/1より実施.” https://www.phileweb.com/news/audio/202505/29/26479.html (published 2025-05-29). Price revision incl. MC275VI→1,540,000円.
[6] Apos Audio, “TOPPING PA7 / PA7 Plus Power Amplifier.” https://apos.audio/products/topping-pa7-pa7plus-amplifier (accessed 2025-08-28). Price and key THD+N/SNR/output specs.
[7] ShenzhenAudio, “TOPPING PA7 Speaker Amplifier.” https://shenzhenaudio.com/products/topping-pa7-speaker-amplifier (accessed 2025-08-28). Alternative price listing.
[8] McIntosh, “Home Audio Electronic Products – Warranty.” https://www.mcintoshlabs.com/Warranty/Home-Audio-Electronic-Products-Warranty (accessed 2025-08-28). 3-year product/90-day tube terms.
[9] Stereophile (F. Kaplan), “McIntosh MC275 power amplifier.” https://www.stereophile.com/content/mcintosh-mc275-power-amplifier (accessed 2025-08-28). Background/design notes.
[10] Emotiva, “XPA-DR2 Differential Reference Two-Channel Power Amplifier.” https://emotiva.com/products/xpa-dr2 (accessed 2025-08-28). Functions and headline power.

(2025.8.28)