iBasso Nunchaku Portable USB Tube DAC/Amp

DUAL JAN6418 TUBES

The Nunchaku features two Raytheon JAN6418 directly heated vacuum tubes, known for their compact size, low power consumption, and reliability. Unlike most portable devices with 5V or 12V power supplies, the Nunchaku uses a dedicated 22.5V anode power supply, providing enhanced headroom and peak tube performance.

TUBE AND CLASS AB OUTPUT MODES

In addition to its TUBE output mode, Nunchaku features a Class AB amplification circuit, allowing users to seamlessly switch between these distinct sonic experiences. TUBE mode delivers a sweet and warm sound, highlighting the exceptional quality of vacuum tubes. Conversely, Class AB mode offers higher resolution and abundant dynamics for a more detailed and impactful listening experience..

UNLEASHING AUDIO EXCELLENCE

Departing from the typical all-in-one chip approach found in most dongles, the Nunchaku adopts a sophisticated OPAMP+BUF634 architecture, a hallmark of flagship audio players. This meticulous design integrates 2 Raytheon vacuum tubes, 4 TI high-performance dual operational amplifiers (OPAMPs), and 4 BUF634A buffers. Within its compact form, the Nunchaku boasts an audio circuit of unparalleled precision, surpassing the limitations of ordinary dongles and delivering an unprecedented level of sound performance.

OVERWHELMING OUTPUT POWER

The Nunchaku delivers up to 525mW+525mW@320Ω in TUBE mode, effortlessly powering flagship IEMs and most headphones. Its potent amplifier integrates 2 Raytheon tubes, 4 TI dual OPAMPs, and 4 BUF634A buffers into a compact design. Despite its power, the Nunchaku remains energy-efficient, consuming just 120mA/5V in TUBE mode and under 100mA/5V in Class AB mode, outperforming many dongles in efficiency.

CS43198 FLAGSHIP DAC

At the heart of the Nunchaku lies a dual implementation of Cirrus Logic's flagship CS43198 DAC chip. Renowned for its exceptional resolution, accurate sound reproduction, wide dynamic range, and exceptionally low noise floor, the CS43198 is a benchmark in digital-to-analog conversion.

JRC HARDWARE VOLUME CONTROL

In TUBE mode, the Nunchaku incorporates a precision JRC hardware volume control. This innovative approach ensures the DAC operates at its maximum output level, followed by a tube amplifier stage and then the JRC volume control. This unique architecture effectively reduces noise as the volume is lowered, significantly enhancing the signal-to-noise ratio and delivering a purer, more refined listening experience.

HAND-SELECTED TUBES

To ensure consistent, high-quality sound, iBasso meticulously pairs JAN6418 tubes using advanced APX555 testing to evaluate SINAD levels. This precise process, limited to 50 matched pairs daily, guarantees exceptional audio performance for every Nunchaku.