オーディオ・音響・アナログレコードのAurorasound（オーロラサウンド）

Product Overview This is an orthodox style pre-main amplifier composed of full-stage vacuum tubes. Input stage ECC83, ECC82, output EL34(6CA7) push-pull and Lundal output transformer with UL connection make 31W+31W output power.This is an orthodox style pre-main amplifier composed of full-stage vacuum tubes. Input stage ECC83, ECC82, output EL34(6CA7) push-pull and Lundal output transformer with UL connection make 31W+31W output power. Amplifier uses the 22mm thick solid maple wood frame and 4mm top solid aluminium plate, thus the body structure is perfectly rigid and no deflection. The heavyweight transformer and sensitive vacuum tube parts are supported by this body to reproduce the substantial mid-low frequencies and delicate high frequencies.　This is designed and manufactured carefully hand crafted so that it can not only meet the needs of the modern digital high-resolution era, but also has sufficient functions and performance for analog playback. This can be used for long years to come as The Tube Amplifier that will remain unchanged for decades.

Standard,   RCA line x4

Features

Various input options

As a basic pre-main amplifier, it is equipped with four RCA line inputs, selector SW and volume. There are three options: 1: XLR balanced input x1 + RCAx3 line, 2: phono input (MM) + RCAx3 line, and 3: RCA/XLR input x1 as a power amplifier. There is a back panel replacement for each one, so please choose in advance.  The phono and XLR input options are semiconductor circuit.

Circuit

The  ECC83(12AX7) is used in parallel for the input stage to reduce the internal impedance of the vacuum tube, reduce noise, and increase the drive power to the next stage. The phase inverter stage adopts a Mullard type using ECC82(12AU7) to achieve stable signal delivery to the final stage. The EL34(6CA7) at the power stage is connected to the output transformer made by Lundal and ultra-linear. The EL34 is self-biasing, so it can be replaced with other brands of EL34 without adjustment. A bias voltage checkpoint is provided near by the socket to check the operating status of the EL34 over a long period of time.The  ECC83(12AX7) is used in parallel for the input stage to reduce the internal impedance of the vacuum tube, reduce noise, and increase the drive power to the next stage. The phase inverter stage adopts a Mullard type using ECC82(12AU7) to achieve stable signal delivery to the final stage. The EL34(6CA7) at the power stage is connected to the output transformer made by Lundal and ultra-linear. The EL34 is self-biasing, so it can be replaced with other brands of EL34 without adjustment. A bias voltage checkpoint is provided near by the socket to check the operating status of the EL34 over a long period of time. By adopting orthodox circuits and standard vacuum tubes, we have taken care to ensure stable operation and maintenance free for many years.

Specifal Parts

Vishay, PRP, and Japanese TAKUMAN are for resistors, WIMA for film capacitors, and TDK-EPCOS is for electrolytic capacitors. We are committed to quality and reliability in these selections. The power transformer and choke transformer are customized by Japanese manufacture, and the rectifier diode is made of ROHM silicon carbide, which is the lowest noise and high voltage resistance of modern times. Speakers and RCA terminals are also carefully selected with thick gold plating.

Bonnet  cover is bundled	Wood Knobs

Top view	Hand wiring and 70um cupper patter PCBHand wiring and 70um cupper patter PCB

各種オプション

Specifications