Exclusive C3a

Commentary

A stereo preamplifier designed with advanced technology and carefully selected parts for beautiful sound.

The equalizer circuit has a high voltage design of 140 v to ensure a high allowable input.

The volume uses a 22-contact attenuator type 4-connected volume.
It is controlled at two places, the top of the flat amplifier and the last stage of the amplifier, and residual noise is reduced.

All parts and wiring materials are of special specifications, and capacitors are made of Mylar, Sticon, Electrolytic, and VII.

In order to minimize distortion, oxygen-free copper wire is used as wiring material.

The substrate is a 140 μ m thick copper foil glass epoxy substrate.
While conventional glass epoxy boards were used by attaching 35 μ m copper foil, we have adopted 140 μ m copper foil, which is four times larger than conventional ones, in order to reduce DCR (direct current resistance) and inductance in the board.

In order to ensure stable performance and reliability, all input / output terminals and assembly terminals are gold-plated to greatly improve the conduction characteristics.
In the past, nickel plating was applied to the base layer in order to stabilize the plating. However, since nickel is ferromagnetic, distortion caused by hysteresis occurred.
The newly developed pin jack used for C3a has been plated on a non-magnetic base material with stability equal to or better than that of nickel to prevent distortion and obtain stable contact performance.

The power cord is double-insulated, high reliability and large capacity (15A) power cord.
In addition, the core wire of the power cord is colored white and black, and the connection with the AC plug is managed to unify the polarity.

The connection code uses a oxygen-free copper wire as the material and a gold-plated plug made of non-magnetic material as the pin plug to minimize the occurrence of strain in the connection code. The connection code structure is different from the conventional coaxial structure in that it uses a star quad system in which opposing core wires of the signal wire are twisted together to reduce inductance. In addition, the signal wire is completely shielded by a conductive polymer material and braiding.
As a result, it is possible to transmit high-quality signals with low distortion and low loss.

Model Rating

Type	Stereo preamplifier
Circuit system	Equalizer amplifier : class A SEPP circuit directly connected to one stage and three stage differential Flat amplifier : 1-stage and 3-stage differential direct-coupled circuit
Input Sensitivity / Impedance	Phono1 : 2.5mV/50k Ω Phono2 : 2.5 mV to 10mV/25k Ω, 50k Ω, 100k Ω Phono3 : 2.5mV/50k Ω Tuner, Aux1, 2, Tape PB1, 2, 3 : 150mV/100k Ω Aux3 : 150 mv ～∞/ 100k Ω
Phono maximum allowable input (Harmonic distortion rate 0.01%, 1 kHz)	Phono1, 3 : 700 mV Phono2:1.4V
Output Level / Impedance	Tape rec1, 2, 3 : 150mV/2.5k Ω OutputA, B (RL: 50k Ω) : 2V/600 Ω (Rating) 15V/600 Ω (maximum) Headphones(RL8 ohm) : 170mV/40 Ω (at Output 100 mv) 500mV/40 Ω (Maximum)
Harmonic distortion factor (20 Hz to 20 kHz)	0.01% or Less (at 2 v Output) 0.01% or Less (at 15 v Output)
Frequency characteristic	Phono : 20 Hz to 20 kHz ± 0.2 dB Tuner, Aux, Tape PB : 20 Hz to 20 kHz + 0 to 0.5 dB 10 Hz to 90 kHz + 0 -1dB
Tone control	Bass main : ± 7.5 dB (100 Hz), 1.5 dB step Sub : + / - 6 dB at 50 Hz, 1.5 dB step Treble Main : ± 7.5 dB (10 kHz), 1.5 dB step Sub : ± 6 dB (20 kHz), 1.5 dB step
Filter	Low cut : 15 Hz (12dB/oct.), 30 Hz (18dB/oct.) High cut : 12 kHz (12dB/oct.), 8 kHz (18dB/oct.)
S/N (IHF, A-network Short circuit)	Phono:80dB Tuner, Aux, Tape PB : 90 dB or higher
Attenuator	-15dB, -30dB
Semiconductor used	Transistor : 65 Diode : 48 pcs
Power supply voltage	100 VAC, 50Hz/60Hz
Rated power consumption (maximum power consumption)	25W (Electrical Appliance and Material Control Law)
Power outlet	Power switch interlock : Route 3 Power switch not linked : Route 3
External dimensions	Width 468x Height 206x Depth 342 mm
Weight	12.5kg
Attachment	Relay cord with pin plug