Accuphase C-2400 (2003)

Name: Accuphase C-2400
Brand: Accuphase

Stereo control amplifier released in August 2003 with AAVA volume control and optional phono stage compatibility.

Overview

The Accuphase C-2400 is a stereo control amplifier released in August 2003. It uses the company's proprietary Analog Vari-gain Amplifier (AAVA) volume control, which has 16 weighted V-I conversion amplifiers and current switches, so there is no mechanical contact. Amplifier circuits and power supplies are separated left and right to prevent interference. For analog playback it takes the optional AD-2800 phono equalizer unit, and it also works with the AD-290/AD-290V phono stages from other Accuphase models.

Specifications

Production Year	August 2003
Original Price	¥ 580,000
Frequency Response (Balanced/Unbalanced)	3 Hz ~ 200 kHz +0 -3.0 dB; 20 Hz ~ 20 kHz +0 -0.2 dB
Total Harmonic Distortion	0.005% (at all input terminals)
Signal-to-Noise Ratio (Balanced)	111 dB (IHF-A, input short, rated output)
Input Sensitivity / Impedance (Balanced)	252 mV / 40 kΩ (rated output)
Rated Output / Impedance (Balanced/Unbalanced)	2 V / 50 Ω
Gain Switch	12 dB, 18 dB, or 24 dB selectable
Tone Control (Bass)	±10 dB at 50 Hz, turnover 300 Hz
Tone Control (Treble)	±10 dB at 20 kHz, turnover 3 kHz
Subsonic Filter	10 Hz: -18 dB/oct
Power Consumption	33 W
Dimensions (W×H×D)	465 × 150 × 403 mm
Weight	17.6 kg

Design

The AAVA volume control combines the amplifier and the volume regulator, so nothing mechanical wears out. Sixteen V-I conversion amplifiers and current switches, run by a CPU, set the volume by combining current signals, which are then converted back to voltage. The tone control uses an additive active filter method. It keeps the signal path flat while it adjusts the response. Input/output switching uses logic relays for a direct signal path. The amplifier circuit is split into five unit amplifiers (input buffer, AAVA, balanced output), physically separated left and right on the motherboard. Power transformers and smoothing circuits are isolated per channel too. The unit also has a headphone amplifier, phase switch, attenuator (-20 dB), and EXT-PRE function for hooking up an external preamp. The AD-2800 phono stage connects through a DIN connector and has Teflon-based circuitry in an aluminum case. It offers two-stage gain switching (MM/MC) and three-stage MC impedance selection (10 Ω, 30 Ω, 100 Ω).

Context

The C-2400 inherits design technology from the C-2800. It shares phono stage compatibility with the AD-2800, AD-290, and AD-290V units used in the C-2800, C-290, and C-290V models. The Accuphase lineup lists it as a preamplifier.

Market

Current market prices include €10,750 (Kleinanzeigen, Feb 26, 2026), €6,250 (Marktplaats, Mar 5, 2026), SEK 40,000 (Hifitorget, Nov 15, 2025), CZK 239,000 (Bazos Czechia, Jan 23, 2026), and €4,280 (Audio-markt, May 1, 2024). A bundled listing for C-2400 with P-6100 and DP-400 reached CZK 275,000 (Bazos Czechia, Jan 14, 2026).