Kojo Technology Nve-03 Car Audio Power Filter + Ground Box
$420.00
Description
Product Website: http://kojo-seiko.co.jp/products/nve03.html
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Product Introduction:
New concept: A conditioner that combines a power filter and ground box!
“Pure Conditioner”
In the past, power filters for car audio systems comprised mainly of composite circuits with large-capacity electrolytic capacitors and choke coils to significantly reduce battery voltage fluctuations and low-frequency noise. Voltage fluctuations in batteries affect the stable operation of in-vehicle electronic devices and have a significant impact on the sound quality of the car audio system. While there persists a market need to address the above issue, the situation is exacerbated by the increasing digitisation of electronic devices in the car including the car audio system which introduces overwhelming amounts of various high frequency noises.
The newly released Kojo Technology Nve-03 is designed to suppress and attenuate such high frequency noises generated by inverters, switching power supplies, internal clocks etc., by arranging film capacitors with excellent high-frequency characteristics by capacitance (decreasing high-frequency impedance). It is also equipped with Kojo’s grounding technology. The result is the realisation of a new concept: A “Pure Conditioner” that also reduces ground noise.
> Use of High-Performance and High Reliability Film Capacitors
The filter uses Okaya Electric noise suppression capacitors and TDK EMI suppression capacitors, which possess excellent high-frequency characteristics and are also used in Kojo’s home audio products. These components provide high reliability and noise reduction thus contributing to the realisation of good sound quality.
> Filters Designed Based On Sound Characteristics
While it is desirable to increase the attenuation frequency band to achieve better noise reduction, doing so in excess will affect the sound characteristics(reproduced sound).
For example, the sound may become very clear but lack emotion or even feels boring. Thus Kojo places great importance on the sound characteristics in the design of the filter and prioritise the listening test before conducting the analysis to confirm the filter characteristics.
The figure shows the frequency characteristics of the filter adopted in the Nve-03. Attenuation begins around 200KHz and reaches about -40dB at around 1MHz, i.e.
for a noise level of 1V, the Nve-03 will attenuate it to 1/100, or 0.01V.
> Effective Board Layout and Internal Wiring Materials
The film capacitors used in the filter are mounted on a board. While the filter characteristics are greatly influenced by the film capacitors employed, the board layout is equally important.
Kojo made full use of its knowledge of board layout technology to achieve higher noise reduction with a beautiful attenuation curve.
In addition, the board layout uses reinforced wiring with a tin-plated single-wire material that actively utilizes the skin effect. To withstand large currents, copper busbars are used for the interface between the large-capacity terminal block and the filter board(to be described later).
> Terminal Block Which Supports High Current + ve-02 Grounding Add-On
The Nve-03 input/output terminal block is of 5-terminal type and able to withstand up to 100A to accommodate the filters of high-capacity power amplifiers.
Connections can be made with an AWG#4 (recommended) cable. In addition, the middle of the five terminals is dedicated for expansion with the Kojo Technology ve-02 Car Audio Ground Box to further improve the sound quality.
> Grounding Section
The Nve-03 also provides grounding in addition to its filter function. Similar to the Kojo ve-02 Car Audio ground Box, it is laminated (layered) with thin plates of different metals. By increasing the surface area of the body ground, the high-frequency impedance is reduced.
The configuration of the 9 layers is as such: (1) steel, (2) copper, (3) brass, (4) copper, (5) brass, (6) copper, (7) brass, (8) copper, and (9) aluminium.
> Body Material for Improved Sound Quality + Robustness
As mentioned above, the grounding section is laminated with different metals which increases the surface area to improve the sound quality. In addition, the Nve-03 chassis can also be seen as part of the grounding section.
Thus, the chassis material also has a great impact on the sound quality. Through repeated prototyping and auditioning, Kojo succeeded in achieving both good sound quality and robustness by using aluminium for the top cover and steel for the bottom chassis.
> Design
The Nve-03 is Kojo Technology’s second car audio accessory! The brand logo and model name are laid out in the centre of the top cover. The N in the model name refers to the noise filter mounted inside, while the ve stands for grounding(virtual earth).
The top cover is made of black anodized aluminum and the bottom chassis has a satin-like black paint finish to give it a heavy, robust and luxurious feel.
The top cover includes The ▲: INPUT and ▼: OUTPUT marks which are inspired by the flow of electricity to improve the visibility of the polarity of the power supply input/output terminal block. It also has the ▼:ADD VE mark which resembles the earth to indicate the terminal for expansion with the Kojo ve-02 Car Audio Ground Box.
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Product Specifications:
Terminal Blocks: M5 5 terminals (recommended power cable: AWG#4)
Input/Output Voltage: DC12V
Input/Output Current: 100A (peak)
Dimensions: W130×H45×D145 (including terminal block and L-shaped bracket)
Weight: Approx. 1.1 kg
Accessories: Instruction manual / Warranty card / L bracket x 2 / L bracket mounting screws (M3 x 4) / Round terminals (M5-AWG4 x 4)
*This product is for car audio use only. Do not use it for any other purpose as it is dangerous. Improper use may damage the equipment or cause personal injury.
