Commentary

This stereo control amplifier is based on the C-200 and C-200S and has been greatly improved by introducing the latest technology.

The cascode bootstrap push-pull differential input method is based on the full-amplification stage push-pull method. The cascode bootstrap improves the high-frequency characteristics while obtaining a large gain. At the same time, it also improves the distortion factor due to the increase in input impedance.
This circuit is used for an equalizer amplifier and a high-level tone control amplifier.

A DC servo system is used for the equalizer amplifier and high-level tone control amplifier, and the input and output of the MM disk are completely directly connected.
The DC servo amplifier uses an IC. The output of the IC does not directly control the signal system of the differential input amplifier, but controls the base current of the constant current source.
This servo circuit minimizes the influence of servo system noise on the signal system and has excellent DC drift control capability. Therefore, it can be used as an equalizer amplifier with a high low-frequency gain for excellent effect.

The head amp section consists of a differential push-pull input and a RET pure complimentary service circuit. The input section, which affects sound quality, is connected directly without using a capacitor.

A multiple power supply system has been adopted in which independent constant-voltage power supplies by RET and IC are arranged in 6 places each on the left and right of the head amplifier, equalizer amplifier and high-level amplifier.
Each is located very close to the circuit and maintains a low impedance across a wider band, reducing interference between units.

The headphone amplifier section uses a DC-configuration A-class pure complimentary service direct connection dedicated amplifier.

A motherboard method is used to connect unit amplifiers, power supply and some functions in a printed circuit.
The glass-epoxy motherboard contains a socket to plug in each unit amplifier, a power transformer and rectifier, a filter condenser and a front panel push switch.
Each part is connected by printed circuitized conductor paths, which eliminates variations in characteristics due to uneven routing that often occurs in wire wiring, and provides uniform performance.

The tone control section uses a 2 dB step method with an independent left / right 11-contact rotary switch, which has been used since the C-200.
There is also a turnover switch and an ON-OFF switch to cancel the tone control.

It is equipped with a Loudness Compensator that adjusts the sound perception and energy balance during low sound playback.
You can choose between two curves depending on the playback level and listening room characteristics.

Equipped with subsonic filter and high filter.

Features include a -20dB attenuator switch, a 5-contact rotary switch mode switch, a disk input impedance selector switch, and an output ON-OFF switch.

There was a wood case sold separately.

Model Rating

Type	Stereo Control Center
Frequency Response (New IHF)	highlevel : 20 Hz to 20 kHz + 0 -0.2 dB Disc : 20 Hz-20 kHz ± 0.2 dB
Total Harmonic Distortion Factor (New IHF)	0.005% or less (20 Hz to 20 kHz)
Input Sensitivity / Impedance (Rated Output / New IHF0.5 v Output)	disc1, discFront MM : 2.0mV/0.5mV/100, 47k, 82k, 150k Ω (head amp off) Disc2MM : 2.0mV/0.5mV/47k Ω (head amp off) Disc MC : 0.1mV/0.025mV/100 Ω (head amp on) Tuner, aux, tape play : 126mV/31.5mV/47k Ω
Rated Output / Impedance	output : 2.0V/2 Ω Tape rec : 126mV/200 Ω (at disc input)
Headphone jack	Output impedance : 0.3 Ω Output : 0.25W (8 ω, 1 khz, 0.01% distortion)
S/N	disc(head amp off): 85 dB (rated input, input short-circuit, A-correction) 82 dB (new IHF) disc(head amp on): 72 dB (rated input, input short-circuit, A-compensation) 74 dB (new IHF) tuner, aux, tape play : 110 dB (rated input, input short-circuit, A-compensation) 88 dB (new IHF)
Input Conversion Noise	disc(head amp off):-139dBV disc(head amp on):-152dBV Tuner, aux, tape play : -128dBV
Maximum Power Level	10 v (distortion factor <0.005%, 20 Hz to 20 kHz)
disc max input (1 kHz, distortion rate less than 0.005%)	head amp off:400mVrms head amp on:20mVrms
Minimum Load Impedance	output : 1k Ω Tape rec : 10k Ω
Gain	tuner, aux, tape play → tape rec:0dB output:24dB disc (head amp off) → tape rec:36dB Output : 60 dB (head amp on : + 26 dB)
Tone Controls	Stepped with 11 contact rotary switch Turnover Frequency Bass : 200 Hz, 500 Hz Treble : 2 kHz, 7 kHz Bass 500 Hz : ± 10 dB (100 Hz), 2 dB step 200 Hz : ± 10 dB (35 Hz) in 2 dB steps Treble 2 kHz : ± 10 dB (10 kHz), 2 dB step 7 kHz : ± 10 dB (35 kHz), 2 dB steps
Loudness Compensator (Volume -30dB)	comp1:+3dB(100Hz) comp2 : + 10 dB at 100 Hz, + 5 dB at 20 kHz
Filters	Subsonic filter : 17 Hz, -12dB/oct High Filter : 8 kHz -12dB/oct
Attenuator	-20dB
Semiconductors used	Transistors : 102 FET : 29 IC : 11 50 diodes
Power Supply	100 VAC / 117 V / 220 V / 240 V, 50Hz/60Hz
Power Consumption	80W
External Dimensions (including legs)	Normal : width 445x height 160x depth 373 mm With Wood Case : width 466x height 190x depth 385 mm
Weight	13.4kg
Sold Separately	Woody case A-8(￥16,000)