Audio Database

CA-606
Commentary

A stereo control amplifier in which all circuits are composed of an NF amplifier with a combination of PNP and NPN transistors.

The equalizer circuit uses an E-E NF type that combines PNP-NPN-PNP transistors.
This circuit uses a PNP transistor at the first stage, which is essentially lower in noise than NPN, and the operating point is rational because the emitter voltage can be freely selected. At the same time, the DC stability is enhanced by the combination of DC and AC NFs.

The intermediate amplifier has a two stage E-B NF circuit with PNP-NPN -NPN at the front and rear stages of the tone control.
This is obtained by adding DC and AC NFs from the emitter to the base. The distortion factor is small and the S/N ratio is high.

The output stage uses an emitter-follower output circuit.
Since a sufficient output level can be obtained with low impedance, there is no adverse effect such as high-frequency attenuation even if the output code is extended.

In addition to the conventional Bass and Treble, the T. T. C is a triple tone control (T. T. C) that adds a Midrange to adjust the middle and high range.
By using the rotary switch, it is possible to adjust high and low frequency in 2 dB steps, and middle frequency in 1 dB steps.

In order to eliminate the electrolytic capacitor from the signal path, a direct-coupled circuit is introduced as much as possible, and a Mylar type circuit with high circuit impedance is used where a capacitor is required between stages.
This improves the high-frequency characteristics.

A constant voltage circuit using a zener diode is used for the DC power supply.
This reduces the drift and improves the stability of the circuit.

Apart from the output circuit, it has an amplifier for exclusive use of headphones.

It is a two tape monitor circuit system that can record on two tape decks at the same time and can monitor either of them.
With the reprint switch, you can easily reprint from deck 1 to deck 2. You can enjoy a completely different source from each monitor or while reprinting.

Input circuits include Phono2, Tuner, AUX and Tape Play Back 2, and an MIC input jack with a phone plug.

Equipped with 12dB/oct NF type low filter and high filter.

Equipped with a muting switch capable of -20dB attenuation with one touch operation.

Equipped with loudness control

The mode switches are : Stereo, Reverse Mono L + R, L, R

Power switch linked AC outlet

Equipped with DIN connector.

Model Rating
Type Preamplifier
Output voltage Maximum output : 3.5 V
Rated output : 1.5 V
Total harmonic distortion factor 0.1% or Less (Rated Output)
Frequency characteristic 15 Hz to 30000 Hz, ± 0.5 dB
Hum and noise (IHF) Phono1, 2 : 75 dB or more
MIC : 80 dB or more
Tuner, Aux : 80 dB or higher
Input Sensitivity / Impedance
(1 khz kHz, rated output)
Phono1 : 2mV/50k Ω
Phono2 : 2mV/50k Ω
MIC : 3mV/50k Ω
Tuner : 180mV/50k Ω
AUX : 180mV/50k Ω
Tape Mon (Pin) : 180mV/50k Ω
Tape Recorder (Din) : 180mV/50k Ω
Recorded output Tape Rec(Pin):180mV
Tape Recorder(Din):30mV
Equalizer Phono : NF, RIAA
Mic : NF Type, Flat
Controls Bass : 50 Hz, ± 10 dB
Midrange : 1000 Hz, ± 5 dB
Treble : 15000 Hz, ± 10 dB
Loudness : + 8 dB (50 Hz), + 3 dB (10 kHz) (Volume -30dB)
SWITCH Low Filter : 30 Hz -12dB (NF Type 12dB/oct)
High Filter : 20000 Hz -12dB (NF Type 12dB/oct)
Tape Monitor 1:Source-Playback
Tape Monitor 2:Source-Playback
Tape to Tape Reprint:Source Record-Deck 1 to 2
Muting:-20dB
Semiconductor used Transistor : 18
Diode : 2
Zener diode : 1
Pwer 100 V, 50Hz/60Hz, 9 VA
External dimensions Width 415x Height 127x Depth 278 mm
Weight 5.7kg