Accuphase C-220 (1977)

Name: Accuphase C-220
Brand: Accuphase

Dedicated high-fidelity phono preamplifier released in June 1977 with switchable MC/MM head-amp and dual output options.

Overview

The Accuphase C-220 is a stereo control amplifier developed exclusively for phono playback, released in June 1977. It functions as a dedicated preamplifier for records, with no auxiliary or tape input terminals. The unit features two phono inputs, each with independently adjustable input impedance (100 Ω, 30 kΩ, 47 kΩ, or 100 kΩ), and includes a built-in switchable head-amp for both MC and MM cartridges, selected via relay control. A reviewer described it as a "world beating phono preamplifier," noting the RIAA equalizer as its standout feature.

Specifications

Frequency Response	20 Hz to 20 kHz ± 0.2 dB
Harmonic Distortion	0.01% (20 Hz to 20 kHz, rated output)
Phono Inputs	2 (DISC1, DISC2)
Input Impedance (Selectable)	100 Ω, 30 kΩ, 47 kΩ, 100 kΩ
Rated Output (Main)	2.0V/50 Ω
Fixed Output	150mV/200 Ω
Gain (DISC → Main Output)	60dB (head amp off), 86dB (head amp on)
S/N Ratio (IHF-A)	85dB (head amp off), 72dB (head amp on)
Input Conversion Noise	-139dBV (head amp off), -152dBV (head amp on)
Power Supply Voltage	100 VAC / 117 V / 220 V / 240 V, 50Hz/60Hz
Power Consumption	65W
Dimensions (Type A)	482 mm W × 82 mm H × 345 mm D
Dimensions (Type B)	445 mm W × 82 mm H × 349 mm D
Weight	10.7kg
Country of Manufacture	JAPAN

Design

The C-220 uses a full-stage symmetric push-pull circuit derived from the P-300 and C-200, improved for enhanced performance. Each amplifier stage, including the head-amp, operates in class A as a DC amplifier without an NF loop capacitor. The MC head-amp employs a differential push-pull stage using four RETs (Ring-Emitter Transistors), combining 100 small-signal transistors in parallel for high gain and superior high-frequency response. The equalizer input uses a FET-buffered differential circuit, and the power supply is stabilized via DC servo amplifier. Output includes both RCA and XLR (Canon) connectors. Two mechanical designs exist: Type A (19-inch rack mount) and Type B (side plate). Shock noise is minimized through timed relay muting, and high-quality, low-resistance relays ensure durability.

Context

The C-220 followed Accuphase's initial product trio—the P-300, C-200, and T-100—positioning itself as a specialized phono preamplifier in the late 1970s. It belongs to a lineage of high-end preamplifiers including the C-200 and C-230. The Type A version aesthetically matches the P-20 and P-60, while the Type B version complements the C-200, P-250, and P-300.

Market

Original price was ¥220,000. Recent market values (2024–2025) range from €2,200 for units in "TOP" condition to €2,800 for fully revised and upgraded models. Common issues include failed relays and aging capacitors—especially electrolytics in the power supply and mylar/large capacitors in the preamp and RIAA stages, which are often replaced during servicing. Units frequently show age-related wear such as scratches and yellowing. Service diagrams are sought after for restoration.