Accuphase C-275V (2000)

At 21.7kg, this preamp doesn’t just sit on the rack—it stakes a claim, promising silence, speed, and surgical precision.

Overview

The Accuphase C-275V isn’t a relic of the tube era or a minimalist audiophile statement. It’s a turn-of-the-millennium declaration of engineering intent from Accuphase Laboratory, Inc.—a stereo control amplifier that treats signal integrity like a sacred contract. Released in May 2000 with a launch price of ¥530,000, it was positioned at the high end of the company’s line, leveraging technology trickled down from the flagship C-290V. This is not a preamp for the casual listener. It’s built for those who demand transparency, low noise, and modular precision, with a fully balanced design and construction choices that prioritize isolation and signal purity over cost or convenience.

Owners report it delivers on that promise. The C-275V operates in line-only mode by default, requiring the optional AD-275V phono equalizer unit to handle turntables—a modular approach that keeps the signal path clean for line sources while allowing vinyl enthusiasts to add phono capability without compromising performance. The unit’s 21.7kg mass comes from serious internal architecture: separate left and right power transformers, thick aluminum housings for individual amplifier stages, and printed circuit boards built on Teflon substrates, a material chosen for its stable dielectric properties and minimal signal loss at high frequencies. This isn’t overkill for show—it’s a deliberate strategy to minimize crosstalk and preserve transient response.

Despite its 2000 release date, the C-275V doesn’t feel like a transitional digital-era component. It’s resolutely analog in philosophy, with discrete circuitry throughout and no concessions to digital inputs or processing. The signal path is managed by logic-controlled relays—industrial-grade, closed-type units with gold-plated crossbar twin contacts—ensuring the shortest possible route between input and output. These relays aren’t just durable; they’re selected for consistent contact resistance and low noise, critical in a preamp where microvolts matter. The front panel includes an output phase switch, a subsonic filter at 25 Hz with a steep -12dB/octave slope, and a three-position compensator for tonal shaping when volume is reduced, all pointing to a design focused on real-world system integration and fine control.

Specifications

Key Features

Current Feedback Circuit Topology

The C-275V employs a current feedback design, a hallmark of Accuphase’s high-end philosophy. Unlike voltage feedback amplifiers, which dominate the market, current feedback circuits offer wider bandwidth and faster transient response—critical for preserving the leading edges of instruments and the spatial cues in complex recordings. This architecture contributes directly to the preamp’s extended frequency response, which reaches 300 kHz at the upper limit. While ultrasonic performance doesn’t translate to audible content, it ensures phase linearity and stability well within the audible band, reducing group delay and preserving timing accuracy. Collectors note that this topology, while less common, is particularly effective in maintaining low distortion across a wide dynamic range.

Balanced Output Stage with Bridged Feedback

The output stage is fully balanced and uses a bridged feedback configuration, a design that cancels even-order harmonic distortion and improves common-mode noise rejection. This is not just a convenience for XLR users—it’s a fundamental part of the signal integrity strategy. By maintaining balance throughout the signal path and using bridged feedback, the C-275V achieves a remarkably low noise floor, especially when paired with balanced power amplifiers. The minimum load impedance is rated at 600 ohms, a conservative specification that ensures stability even with long cable runs or less-than-ideal downstream components.

Pure Complimentary Service Push-Pull Circuit (Discrete Parts)

The line amplifier section uses a pure complimentary push-pull circuit built entirely from discrete transistors—no op-amps, no integrated circuits. This approach allows for tighter control over component matching and thermal behavior, resulting in symmetrical performance between positive and negative signal swings. The use of discrete parts also enables Accuphase to optimize each stage for specific performance goals, such as slew rate and open-loop bandwidth, without being constrained by off-the-shelf IC limitations. This is a labor-intensive method, but one that owners report pays off in dynamic clarity and low intermodulation distortion.

Teflon-Based Printed Circuit Boards

The use of Teflon (PTFE) as a substrate for the printed circuit boards is a high-cost, high-performance choice. Teflon has one of the lowest dielectric constants among PCB materials, which reduces signal loss and capacitance between traces. It’s also highly stable across temperature and humidity variations, ensuring consistent performance over time. While fragile and difficult to manufacture with, Teflon boards are a favorite in high-frequency and precision analog applications. In the C-275V, they support the preamp’s wide bandwidth and low phase shift, particularly in the ultrasonic range.

Complete Mono Construction with Separate Transformers

True to its high-end ethos, the C-275V features complete mono construction—separate power transformers for the left and right channels. This eliminates any possibility of power supply crosstalk, a subtle but real issue in stereo components that share a single transformer. Each channel operates from its own isolated power source, contributing to a wider, more stable soundstage. The transformers are housed in thick aluminum enclosures, further shielding them from electromagnetic interference. This level of isolation is rare even in modern high-end gear and speaks to Accuphase’s commitment to channel separation.

Fully Modular Construction with Separate Amplifier Stage Units

Every amplifier stage in the C-275V is built as a separate module, physically isolated within its own thick aluminum housing. This modular design isn’t just for serviceability—it prevents thermal and electromagnetic coupling between stages. Each module can be individually tested, tuned, and replaced if necessary, a feature appreciated by technicians and long-term owners. The construction also allows for precise grounding schemes, minimizing ground loops and hum. While this approach increases manufacturing cost and complexity, it results in a cleaner, more controlled signal path.

Logic-Controlled Relays with Gold-Plated Crossbar Contacts

Signal routing is handled by industrial-grade, closed-type relays designed for the communications industry. These are not standard automotive or consumer relays—they’re built for high reliability and low contact resistance. The gold-plated crossbar twin contacts ensure consistent conductivity and resist oxidation over time. Logic control means the relays are switched by low-level signals, preventing any high-current switching noise from affecting the audio path. The result is a near-instantaneous, wear-resistant switching system that maintains signal integrity across thousands of operations.

Three-Position Compensator for Volume-Dependent Tone Shaping

The compensator is a thoughtful feature for real-world listening. When volume is reduced, human hearing loses sensitivity to bass and treble (the Fletcher-Munson effect). The C-275V addresses this with three selectable curves: +3dB at 100Hz, +6dB at 100Hz, or +6dB at both 100Hz and 20kHz. This allows users to maintain tonal balance at lower listening levels without resorting to tone controls that can degrade sound quality. It’s a subtle but effective tool, especially in smaller rooms or late-night sessions.

Subsonic Filter at 25 Hz, -12dB/Octave

The subsonic filter is essential for vinyl playback, especially when the AD-275V phono unit is added. It rolls off frequencies below 25 Hz at -12dB per octave, eliminating rumble, turntable noise, and port resonance from bass reflex speakers without affecting the audible bass. This slope is steep enough to be effective but gentle enough to avoid phase distortion in the low bass. It’s a practical safeguard that protects downstream amplifiers and speakers from wasting power on inaudible frequencies.

Integrated Headphone Amplifier Circuit

Despite being a line preamp, the C-275V includes a built-in headphone amplifier designed for high fidelity. This isn’t an afterthought—it’s a dedicated circuit meant to preserve the preamp’s sonic character when driving headphones directly. The inclusion suggests Accuphase anticipated use in both high-end stereo systems and private listening scenarios, a flexibility that remains appreciated today.

Remote Commander RC-26 for Volume and Input Control

The included RC-26 remote allows full control over volume and input selection, a convenience that doesn’t compromise the analog signal path. The remote communicates with the unit via infrared, and all switching is still handled by relays—no digital potentiometers or stepped attenuators that could degrade sound. This maintains the integrity of the volume control while adding usability.

Optional AD-275V Phono Equalizer Unit

The C-275V is line-only by design, but it can be upgraded with the AD-275V phono equalizer unit, which provides both MM and MC inputs with switchable impedance and gain. The AD-275V is not compatible with other models except the C-275 and C-275V, underscoring its specialized role. When attached, it extends the preamp’s depth by 9mm and adds 0.8kg to the total weight. The modular phono stage ensures that the sensitive RIAA equalization circuitry is isolated from the main unit, minimizing noise and crosstalk.

Collectibility & Value

The C-275V was sold with the Remote Commander RC-26, and the AD-275V phono equalizer unit was available separately for ¥100,000. Current market prices vary significantly depending on condition, accessories, and region. Listings show a wide range: approximately $1,500 for a standalone unit (Raw Research), up to $9,000 when paired with a P-1000 power amplifier, and prices in Poland ranging from PLN 13,500 to 28,900 (OLX Poland). This variability reflects the lack of a standardized market for this model, with prices influenced heavily by completeness and local demand. Units with the AD-275V and original packaging likely command premiums, especially in regions where Accuphase has a strong following.

eBay Listings

Accuphase C-2300 Preamplifier 220V

$7,390

ACCUPHASE C-270 Stereo Preamplifier 100V USED JAPAN control

$2,800

Accuphase C-290V Stereo Preamplifier

$6,000

Accuphase C-2800 Control Amplifier Tested AC100V Excellent w

$6,203

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