Audio Database
C-222
Commentary

As a successor to the C-220, whose production was terminated in 1980 due to the unavailability of major components, this control amplifier focuses on disc playback while improving input terminals and functions.

The circuit configuration of the equalizer amplifier and high-level amplifier consists of differential input via FET buffer, pre-drive by cascode and final by Darlington. All stages are push-pull.
As a result, the element characteristics before NFB are improved and high quality is achieved.

The head amplifier for the MC cartridge has a configuration in which a dedicated flat amplifier is inserted in front of the equalizer amplifier. The circuit configuration is directly input without the FET buffer. Low-noise elements are carefully selected. At the same time, the impedance of the NFB loop is reduced to prevent noise generation.
The MC head / N of the signal system is greatly affected by the noise of the constant voltage circuit of the power supply in the MC head amplifier section, the elements of the constant voltage power supply section are carefully selected and a thorough low-noise design is applied.
The maximum input voltage is 150 mV to prevent saturation even when a strong MC input passes through.

Each of the equalizer amplifier, high-level amplifier and head amplifier has an IC-based DC servo circuit. The DC generated at the output is detected and returned to the input to prevent DC drift.
As a result, almost no DC drift is generated, and all signal systems from MC input to output are directly connected.

Each unit amplifier is driven by an independent coil independent rectifier circuit. In addition, a constant voltage power supply circuit is installed near each unit amplifier in the multiple power supply system. Thus, a theoretically perfect independent power supply is constituted.

The signal from the input terminal is directly connected to the printed circuit board, the relay is turned on at the closest position, and the relay is controlled by the logic circuit. This minimizes the signal path and prevents signal degradation due to excess wiring.
The relay used for this purpose uses a high reliability crossbar twin-type relay developed especially for audio applications. The contact is sealed with a thin gold film on a silver-palladium alloy to shield it from the outside air and improve durability.

It is compatible with various MC cartridges, and the MC input impedance can be switched to 3 levels to enable fine control of sound quality.
In addition to the normal head amplifier gain of 26 dB for the low power MC cartridge, a gain selector switch is provided to obtain a high gain of 32 dB.

It is equipped with MM load capacitance switching function which finely adjusts the high frequency characteristics of MM cartridge, and 3 types of capacity can be added.

Equipped with 2 tape connection terminals for recording, playback and monitoring.

It is equipped with an attenuator that can lower the level without changing the volume control, and the level can be lowered to -20dB.

Equipped with a -12dB/oct subsonic filter that cuts only subsonic noise without affecting the audible band.

As an alternative to the tone control, it has a compensator that automatically adjusts the frequency response according to the position of the volume. This function can be switched from one of two characteristics to another.

Equipped with a headphone port.

There are two types of front panel designs, the C-222A with the same gold finish as the main body of the front panel, and the C-222B with only the sub-panel finished in black.
Also, there was a cabinet with natural rosewood finish sold separately.

Model Rating
Type Stereo Preamplifier
Frequency Response
Tuner, Line, Tape play : 1.0 Hz to 500 kHz + 0 -3.0 dB
20 Hz ~ 20 kHz + 0 -0.2 dB
Disc : 20 Hz-20 kHz ± 0.2 dB
Total Harmonic Distortion Factor (IHF) 0.005% (20 Hz to 20 kHz at all input terminals)
Input Sensitivity / Impedance
(Rated Output / IHF Output 0.5 v)
Disc (Head amp off) MM : 2.0mV/0.5mV/47k Ω
Disc (Head amp + 26 dB) : 0.1mV/0.025mV/10 Ω, 30 Ω, 100 Ω
Disc (Head amp + 32 dB) : 0.05mV/0.0125mV/10 Ω, 30 Ω, 100 Ω
Tuner, Line, Tape play : 126mV/31.5mV/20k Ω
Rated Output / Impedance Outputs : 2.0V/1.0 Ω
Tape rec : 126mV/200 Ω (at disc)
S/N / Input conversion noise
Input Short IFF-A Correction
Input Terminal Rated Input S/N Input Conversion Noise IHF S/N
Disc(Head amp off)MM: 85dB -140dBV 85dB
Disc(Head amp +26dB): 72dB -152dBV 78dB
Disc(Head amp +32dB): 66dB -152dBV 78dB
Tuner, Line, Tape play : 110dB -128dBV 90dB
Maximum power level
(0.005% distortion rate, 20 Hz to 20 kHz)
Outputs:8.0V
Tape rec : 19.0 v (at disc)
Headphone jack Applicable Impedance : 4 Ω ~ 100 Ω
Disc Maximum Input Voltage
(1 kHz, 0.005% distortion)
Head amp off:300mV
Head amp +26dB:15mV
Head amp +32dB:7.5mV
Minimum Load Impedance Outputs : 1k Ω
Tape rec : 10k Ω
Gain Tuner, Line, Tape play → Outputs : 24 db
Tuner, Line, Tape play → Tape rec : 0 dB
Disc (Head amp off, MM) → Outputs : 60 dB
Disc (Head amp off, MM) → Tape rec : 36 dB
Head amp is switchable between + 26 dB and + 32 dB
Loudness Compensator
(Volume -30dB)
1:+3dB(100Hz)
2 : + 8 dB at 100 Hz, + 6 dB at 20 kHz
Subsonic Filter 17 Hz, -12dB/oct
Attenuator -20dB
Semiconductors used Transistors : 109
FET : 9
IC : 13 pcs
94 diodes
Power Supply Voltage 100 VAC / 117 V / 220 V / 240 V, 50Hz/60Hz
Power Consumption 50W
External Dimensions Width 445x Height 128 (w / legs) x Depth 373 mm
W 466x H 153x D 385 mm (with wood cabinet)
Weight 9.7kg
Sold Separately Wood Cabinet A-9(¥16,000)