Audio Database

The

Exclusive C3a
430,000yen(around the 1981 time)

Description
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The stereo preamplifier which pursued a beautiful sound and was completed with an advanced technology and the component partses selected carefully.

The equalizer circuitry has secured the high allowable input by the high-voltage design of 140V.

The attenuator type 4-unit volume of 22 contacts is adopted as a volume.
It has controlled with the top of flat amplifier at two places of the last stage of amplifier, and the remains noise is reduced.

The thing of special edition is altogether adopted as a part or product-line material, and contest a Mylar, the polystyrene capacitor, contest electrolysis, and contest VII are adopted as a capacitor.

In order to suppress a distorted occurrence as much as possible, the oxygen-free-high-conductivity-copper line is adopted as product-line material.

The 140micro thickness Copper-foil glass epoxy group board is adopted as a substrate.
Although the conventional glass epoxy group board was sticking and using a 35micro Copper foil, in order to aim at DCR (direct current resistance) in a substrate, and a falloff of an inductance, the 140micro Copper foil which increases 4 times over the past is adopted.

In order to secure the stable performance and robustness, all of an input/output terminal and the termination of each assembly are raising the conduction characteristic sharply, such as using gilding.
In order to stabilize a plating and to stick conventionally, nickel plating had been performed to the ground. However, since ferromagnetic material, nickel had the distorted occurrence resulting from a hysteresis.
It plated with the newly developed pin jack adopted as C3a on the ground of non-magnetic material which shows nickel, equivalent, or the stability beyond it, and the distorted occurrence was prevented and the stable contact performance has been obtained.

The hi-reliability and the mass (15A) power cord which performed the double insulation are adopted as a power cord.
Furthermore, the polar unification is aimed at by classifying the cable of a power cord by color by white and black, and managing the interconnection with AC plug.

A connecting cord is suppressing the distorted occurrence in a connecting cord, such as using for a pin plug the gilding plug which consists of a non-magnetic-material ground, as much as possible while using an oxygen-free-high-conductivity-copper line for a material. Moreover, the structure of the connecting cord is aiming at the reduction of the inductance by adopting a different star-quad scheme from the conventional coaxial structure which made the cable with which a signal line counters mutually gather. Furthermore, the perfect shielding according a signal line to an electrically conducting polymer material and a braid is performed.
There is little distorted occurrence by these and quality signal transmission is possible at a low loss.

Rear
The

Rating of a mode
Form Stereo preamplifier
Circuit system Equalizer amplifier: Differential three-step hardwired-connection Class-A SEPP circuit per step
Flat amplifier: Differential three-step hardwired-connection circuitry per step
Input sensitivity/impedance Phono1:2.5mV/50kohm
2:2.5 mV - 10mV of Phono / 25kohm, 50kohm, 100kohm
Phono3:2.5mV/50kohm
Tuner, Aux1, 2, Tape PB1, 2 or 3:150mV / 100kohm
Aux3:150mV - infinity/100kohm
Phono maximum permissible input
(0.01% of a THD, 1kHz)
Phono1, 3:700mV
Phono2:1.4V
An Output voltage/impedance Tape rec1, 2 or 3:150mV / 2.5kohm
OutputA, B (RL:50kohm) : 2V/600 ohm (rate)
15V/600 ohm (maxima)
Headphones (RL: 8ohms) : 170mV/40 ohm (Output 100mV o'clock)
500mV/40 ohm (maxima)
THD (20Hz - 20kHz) 0.01% or less (at the time of 2V output)
0.01% or less (at the time of 15V output)
Frequency characteristic Phono: 20Hz-20kHz}0.2dB
Tuner, Aux, and Tape PB:20Hz-20kHz+0 -0.5 dB
10Hz-90kHz+0 -1 dB
Tone control Bass main: }7.5dB (100Hz), a 1.5dB step
Factice: }6dB (50Hz), a 1.5dB step
Treble main: }7.5dB (10kHz), a 1.5dB step
Factice: }6dB (20kHz), a 1.5dB step
Filter Low cut: 15Hz (12 dB/oct), 30Hz (18 dB/oct)
High cut: 12kHz (12 dB/oct), 8kHz (18 dB/oct)
S/N (IHF, A network)
Short circuit
Phono:80dB
Tuner, Aux, Tape PB: 90dB or more
Attenuator - 15dB-30dB
The semiconductor used Transistor: 65 pieces
Diode: 48 pieces
Supply voltage AC100V, 50Hz/60Hz
Power dissipation
(maximum electric power consumption)
25W (Electrical Appliance and Material Control Law)
Power receptacle Power-switch interlock: Three lines
Power-switch un-interlocking.: Three lines
Dimensions Width 468x height 206x depth of 342mm
Weight 12.5kg
Adjunct A relay code with a pin plug