Accuphase C-11 (1989)

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

Overview

The Accuphase C-11 is a stereo preamplifier made in Japan and released in July 1989. It has balanced XLR inputs and outputs, plus separate MM and MC phono inputs for a turntable. The "C" in the model name marks it as a control amplifier (preamp) in 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 uses a balanced input/output circuit with XLR-type connectors. The high-level amplifier has a cascode differential input and a class A push-pull output stage. The phono stage has separate circuits for MM and MC cartridges. The MM side uses an FET para-input circuit to keep input impedance high. The MC side uses a low-noise component design. Signal path switching is done by a logic-controlled, sealed audio-grade relay with a crossbar twin contact system. Volume is adjusted remotely with a motor-driven manual potentiometer, which preserves sound quality. The tone controls use an additive filter design. The unit also has 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."