產品特色
It is three hybrid drivers and full analog multi-amplifier system.
The left figure below shows a conventional system and the right is a simplified example of FUGAKU's multi-amplifier system.
The conventional method is amplifier → passive filter → driver, in that order,
FUGAKU's method is active filter → amplifier → driver, in that order.
In conventional systems, there is a passive filter, a circuit for bandwidth division, between the amplifier and the driver, and the amplifier cannot drive the driver directly, resulting in a loss of directness in the sound.
In addition, passive filters must be small to fit into the earphone housing, resulting in a simplified design. As a result, it becomes difficult to make the frequency response ideal for the designer.
There are several other negative factors in sound quality in exchange for versatility, such as the fact that a single amplifier drives multiple drivers, so the more drivers you add, the lower the impedance, the higher the load on the amplifier, and the more prone to distortion.
To overcome these problems, FUGAKU has adopted a multi-amplifier system. This is a method that has existed in the speaker world for a long time in a small number of cases.
This is the world's first hybrid-driver earphone and full-analog multi-amplifier configuration, which first divides the bandwidth and then drives each driver with an amplifier prepared for each band.
It is no longer necessary to fit the filter into the earphone housing, and a sophisticated active filter consisting of an OPAMP can be used.
As a result, even higher-order steep filters can be built, and the frequency response that most affects sound quality can be freely designed. In addition, the ability to use large volumes of high-quality components with large volume, such as film capacitors, makes it possible to achieve high quality on a component-by-component basis.
Not only that, but since the amplifier and driver are directly connected, the driving power is high, enabling unprecedentedly direct sound. Another advantage is that as the number of drivers increases, so does the number of amplifiers, resulting in a lighter load per amplifier and less distortion.
The supposed disadvantages of this method are the reverse of the advantages of the conventional method.
This method requires a dedicated amplifier and a dedicated multi-pole cable, which reduces versatility and increases cost, but the sound quality benefits greatly outweigh the cost.
While a multi-amp system for speakers requires a separate preamplifier, active filter, and multiple power amplifiers, FUGAKU combines these components in a single housing to provide the ultimate sound on a scale equivalent to a conventional player + portable amplifier combination.
Earphone
These earphones are a high-level fusion of conventional drivers (dynamic and balanced armature types) and new drivers (MEMS speakers).
Since the active crossover is built into the dedicated portable amplifier, there is no crossover circuit inside the earphone case, and each driver is directly connected to the amplifier.
The excellent physical characteristics of the 3D sound conduit, titanium stem, and gold-plated OFC ring, which are integrally molded into the 3D printed driver unit holder, and the optimal parameter settings of the active crossover, have resulted in acoustic characteristics that are smoothly connected across the entire bandwidth.
Based on years of experience in designing, developing, and manufacturing custom IEMs and universal IEMs, we have created an enclosure shape that provides excellent fit and sound insulation.
The cable is attached downwards and an ear hanger system is adopted to suppress misalignment in the direction of rotation, achieving a very high wearing stability despite being universal earphones.
A specially designed 7-pin cable connection is used for the cable connection. Despite its small size and multiple contacts, the design is harmonious and integrated with the earphone housing.
Dedicated portable amplifier
This is a portable amplifier dedicated to FUGAKU, which is both compact and usable for a long period of time, while placing the highest priority on sound quality and multiplying the amount of material.
Based on the feedback obtained from TSURANAGI, a new circuit was used for the differential line receiver and electronic volume, while the power amplifier was brushed up, new circuits were adopted, and the amplifier was developed into a multi-amplifier with an active crossover after many improvements.
To achieve the same size as TSURANAGI without sacrificing convenience, the interior is implemented in three dimensions. The main board has a two-story structure with two boards. The first floor is a four-layer board and mainly consists of power and control circuits, while the second floor is an eight-layer board with separate functions for only the analog circuit amplifiers.
From the main board to the input/output terminals is wired with pure silver wire, the same wire material as the dedicated cable.
A large-capacity capacitor of more than 10,000μF is effectively arranged in the power supply circuit, contributing to a low-center-of-gravity sound quality. In addition, 14 ultra-high-performance linear power supply circuits are implemented to thoroughly prevent interference between circuits.
Dedicated cable
This 16-core cable with pure silver conductor is designed specifically for this system to transmit power amplifier signals to each driver without loss.
The use of newly developed high-purity pure silver wire material provides high flexibility, ease of use, and excellent sound quality despite its multi-core nature.
Based on the tuning method for pure silver wire developed for SHIROGANE, we have applied the Ultimate grade of exclusive high sound quality processing.
