Accuphase C-11 (1989)

Name: Accuphase C-11
Brand: Accuphase

Stereo preamplifier with balanced circuitry and dual phono inputs, released in July 1989.

Overview

The Accuphase C-11 is a stereo preamplifier manufactured in Japan and released in July 1989. It features balanced XLR inputs and outputs, along with dedicated MM and MC phono inputs for turntable connectivity. The "C" in its model name designates it as a control amplifier (preamp) within the Accuphase lineup.

Specifications

Production Year	July 1989
Original Price	￥220,000
Frequency Response (Balanced Input)	1.0 Hz to 400 kHz +0 -3.0 dB; 20 Hz ~ 20 kHz +0 -0.2 dB
Total Harmonic Distortion Factor	0.005% (at all input terminals)
External Dimensions	Width 445 x Height 95 (including legs) x Depth 325 mm
Weight	9.3kg
Power Consumption	28W
Input Sensitivity/Impedance (AD MC)	0.13mV/0.032mV/100 Ω
Rated Output/Impedance (Balanced Output)	2.0V/50 Ω, XLR connector
Included Remote	Remote Commander RC-3

Design

The C-11 employs a balanced input/output circuit with XLR-type connectors. Its high-level amplifier uses a cascode differential input and class A push-pull output stage. The phono stage has separate dedicated circuits for MM and MC cartridges: an FET para-input circuit for MM to maintain high input impedance, and a low-noise component design for MC. Relay switching is used in the signal path via a logic-controlled, sealed audio-grade relay with a crossbar twin contact system. Volume is adjusted remotely using a motor-driven manual potentiometer to preserve sound quality. Tone controls use an additive filter design, and the unit includes a loudness compensator linked to volume level, a subsonic filter at 17 Hz (-12dB/oct), and a -20dB attenuator.

Market

The Accuphase C-11 had an original retail price of ￥220,000. In 2011, a used C-11 paired with a P-11 power amp was listed for nearly $2400 USD, with suggestions to negotiate around $2000. A fully serviced unit was listed for $2,102.84 approximately four years prior to the listing date. A separate sale noted a locally sold unit at ~$900. A 2011 Bluebook valuation listed the C-11 alone at $820. A current listing on Taste For Audio shows a price of €1,350 for a unit in "Very Good Condition."