Delivery time approx. 2-3 months
The next generation of portable reference amplifiers from Brise Audio
- Pure analog portable amplifier with balanced input/output
- Uses pure silver wire with maximum conductor volume
- Internal high-quality sound processing optimized for pure silver wire
- Provides a balanced output even for unbalanced input signals
- Input: Balanced/unbalanced (5-pin 4.4mm / 3-pin 3.5mm)
- Output: Symmetrical (5-pin 4.4mm)
- Integrated circuit technologies developed by FUGAKU (BIS2.0, BOS1.5, BPS1.5)
- Compared to TSURANAGI-V2: Maximum power at 16Ω increased about threefold to 2000mW+2000mW, THD+N reduced to one third, and residual noise reduced by half
- Equipped with the high-quality electronic volume IC MUSES72320
- Drives headphones with a low-distortion current-feedback amplifier
- Eliminates input/output coupling capacitors by using two power supplies and a DC servo
- Upgraded from a conventional extruded aluminum housing to a more robust CNC-machined aluminum structure
- Improved feel and texture through the use of forged carbon and Ultrasuede®
- Approx. 8 hours of continuous playback (may vary depending on usage conditions)
Product concept
To keep pace with the evolving portable amplifier environment in recent years, we developed WATATSUMI as a reference for next-generation portable amplifiers.
The original TSURANAGI was developed as a reference evaluation environment for cable development.
This portable amplifier features a balanced 4.4mm input and output that has become mainstream in the portable audio world, striving for sound quality that doesn't become a bottleneck for our cables.
More than four years have passed since the release of the original TSURANAGI, and our cable range has evolved with it.
At Brise Audio, we now offer a variety of models, including SHIROGANE, which uses pure silver conductors, and OROCHI, which contains a large volume of conductors.
In recent years, the high-end headphone market has seen an increase in low-impedance headphones, leading to a higher demand for low-noise amplifiers.
At the same time, there is an increase in high-end headphones that require a lot of power, which increases the demand for amplifiers with high output power.
With these factors in mind, we developed WATATSUMI to redefine our high-end cable evaluation environment.
WATATSUMI takes the concept of the original TSURANAGI and strives for improvement in every aspect. To achieve this, we redesigned the circuitry from scratch, adopting the low-noise BIS2.0 input stage from the FUGAKU. The output amplifier has also been improved.
design
The WATATSUMI has increased the number of components to achieve a significant improvement in sound quality.
To maintain a comparable size to previous models, the case was CNC machined from a solid block of aluminum, allowing for higher density and a more flexible internal layout.
The battery capacity has been increased by more than 10% compared to previous models, and the battery decoupling capacitors have been increased to 4000μF - four times the previous amount.
To effectively accommodate the larger battery, increase noise resistance in the circuits, and improve heat dissipation for the power supply and power amplifier, a custom CNC-machined aluminum shielding enclosure was used.
The power supply and power amplifier circuits mounted on the PCB are thermally coupled to the shielding case, and the structure that dissipates heat via side vents follows the same design as FUGAKU.
While the amplifier generally does not generate significant heat, the power amplifier that drives earphones and headphones can temporarily generate high levels of heat when outputting large currents.
Since amplifier performance in terms of distortion and noise can fluctuate with temperature changes, a heat dissipation structure has been implemented to suppress temporary thermal fluctuations and ensure consistent sound quality under all conditions.
The WATATSUMI eliminates the toggle switch for selecting the input signal and replaces it with an automatic selection function that detects the insertion and removal of the plug.
To avoid noise when plugging and unplugging the connector, the 4.4mm output jack is also monitored and the output relay is switched off when no earphone or headphones are connected.
To prevent accidental operation or damage to the volume control, a protective guard has been installed around it. This guard is integrated into the aluminum housing and CNC-machined in one piece.
The volume control has been changed from brass to a titanium alloy, and its durability has been further improved with a PVD coating.
Accordingly, the case screws were also replaced with ones made of pure titanium.
The battery indicator has been increased from three to four levels, allowing for more accurate monitoring of the remaining battery charge.
The bottom of the device is partially coated with Ultrasuede to prevent damage to the device and surrounding surfaces.
A forged carbon plate, similar to the FUGAKU, is attached to the top of the device, which contributes to both the aesthetics of the design and weight reduction.
Audio performance development
The circuit board still consists of 6 layers, but the thickness of the copper foil has been doubled to reduce wiring resistance.
This contributes in particular to improved bass reproduction and texture.
In contrast to the TSURANAGI series, which used a mirrored layout between the left and right channels, the WATATSUMI series redesigned the component arrangement and routing. The layout is essentially left-right symmetrical, with some sections mirrored between the channels.
The input amplifier, electronic volume control and voltage amplifier are located in the center, while the output amplifiers are arranged symmetrically on the left and right sides.
The single-point ground, which serves as the circuit's reference, is placed at the top center, and the layout ensures that it is as far away as possible from the left and right circuits while minimizing the distance to the output amplifiers.
By reducing the wiring impedance, implementing a symmetrical layout, and reviewing the circuit components, the THD+N value at the high current output was reduced.
The result is improved source fidelity, delivering pleasant and stable sound quality with minimal distortion even at higher volumes.
Pure silver wire with maximum conductor volume
While WATATSUMI uses pure silver wire internally, it plays the same role as TSURANAGI as an amplifier for evaluating the connected cables.
It is designed with a neutral sound signature to utilize the full potential of any connected cable or playback device.
Pure silver is said to have about 5% higher electrical conductivity than pure copper.
In current-carrying paths, such as amplifier outputs, losses due to line resistance are more noticeable, so the high conductivity of silver is a significant advantage.
By using pure silver wire with a larger conductor volume than SHIROGANE, the output resistance has also been reduced to a minimum.
Specifications
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