The JAVA Hi-Fi Carbon Single Shot 400 combines an LDR-based preamplifier and GaN FET power amplifier in a single enclosure. Its single-ended RCA signal path provides direct signal transmission and a rated output of 400 W per channel for demanding stereo systems.

Alongside its line-level sources, the amplifier includes an 18-bit NOS R-2R DAC based on the Analog Devices AD1865, an MM phono stage and Bluetooth aptX connectivity. A headphone output, variable-level RCA output and remote control for volume and source selection provide flexible system integration.

The Carbon Single Shot 400 features a next-generation Class D output stage based on gallium nitride transistors. Compared with conventional silicon MOSFETs, GaN FET technology enables faster switching that more closely approaches the theoretical ideal, supporting high linearity, low distortion and reduced electromagnetic emissions.

JAVA GaN modules operate in a closed control loop at switching frequencies between 400 and 500 kHz. Selected through laboratory measurements and listening tests, this operating range balances efficiency, stability and sound quality, while the amplifier delivers a rated output of 400 W per channel into 8 Ω.

Instead of a conventional potentiometer, the preamplifier stage uses light-dependent resistors, or LDRs, for volume control. The control current adjusts the brightness of an internal LED, and the resulting light intensity changes the resistance to set the signal level.

JAVA’s proprietary LDR circuit separates the audio signal path from the control electronics and employs contactless input switching. With no metal or carbon wiper of the type used in conventional volume controls placed in the signal path, the sensitive analogue signal can follow a short and direct route.

The design uses NSL32SR3 LDRs. The passive preamplifier stage provides precise volume control without introducing an active gain device, while both volume and source selection can also be operated remotely.

The Single Shot configuration uses a single-ended RCA-based signal path. Two pairs of line-level RCA inputs allow two analogue sources to be connected, while the variable-level RCA output can be used with an external power amplifier or active subwoofer.

The line-level and MM phono RCA connections of the Carbon Single Shot 400 use ETI Research Silver sockets. These highly conductive connectors provide a stable, low-loss connection while keeping the signal path between the LDR preamplifier and GaN FET power stage short and direct.

This configuration is designed for systems built around RCA-connected sources that require the same rated output of 400 W per channel as the Double Shot models.

The built-in USB DAC is an 18-bit non-oversampling (NOS) R-2R converter based on the Analog Devices AD1865 and supports files with sampling rates up to 768 kHz. Its resistor-ladder architecture provides direct digital-to-analogue conversion without oversampling.

The DAC is powered by its own linear voltage regulator, while native MSB adjustment within the AD1865 improves linearity, particularly around the zero-crossing point. Digital playback is complemented by an MM phono stage fitted with an ETI Research Silver RCA socket, Bluetooth aptX connectivity and a dedicated headphone output.

A defining feature of the Carbon Series is its 9 mm-thick solid carbon-fibre outer casework. The favourable vibration-damping properties of carbon fibre reduce the influence of mechanical disturbance on the sensitive audio circuitry.

The casework also helps reduce the ingress of radio-frequency and electromagnetic interference into the amplifier. This is particularly important around the preamplifier and phono circuits that handle low-level analogue signals.

The carbon-fibre outer casework is complemented by an 8 mm-thick black anodised aluminium front panel. This mechanical construction protects the sensitive internal components, enhances durability and creates the consistent visual identity of the Carbon Series.

The upgraded power supply of the Carbon Series uses premium Mundorf capacitors. These high-quality components support the stable power delivery required by the high-output GaN FET power stage and the consistent operation of both amplifier channels.

The loudspeakers connect through ETI Research Kryo binding posts. These robust, high-current connectors provide a reliable connection between the amplifier and the speaker cables.

The audio circuitry is mounted on an inverted printed circuit board. This structural arrangement reduces the influence of mechanical vibration and resonance on the circuitry.

The enclosure rests on IsoAcoustics Gaia IV isolation feet. These mechanically decouple the amplifier from its equipment rack or furniture and reduce the transmission of environmental vibration into the chassis and internal circuitry.

Weighing 15.4 kg, the amplifier measures 440 mm wide, 415 mm deep and 130 mm high. Its wide, low-profile enclosure provides stable placement, while the carbon-fibre casework and black aluminium front panel reflect the technical construction in its exterior design.