Nunchaku

Dual Raytheon JAN6418 Tubes | 22.5V Anode Power Supply
The Nunchaku utilises two Raytheon JAN6418 directly heated vacuum tubes, renowned for their compact size, low power consumption and operational stability. Unlike most portable products that use 9V or 12V power supplies, the Nunchaku features a dedicated 22.5V anode power supply for the JAN6418 tubes. This higher voltage provides increased headroom, allowing the tubes to operate at their full potential.

The dual JAN6418 tubes give the Nunchaku a distinctly analogue sound signature, with a warm, smooth and relaxed tube character that delivers an engaging analogue-style listening experience.

Tube and Class AB Output Modes | Switch Between Tube Warmth and Precise Sound
In addition to Tube mode, the Nunchaku also features a Class AB amplification circuit, allowing users to switch between the two output modes. Tube mode delivers a sweet, warm and smooth presentation that highlights the character of vacuum tubes, while Class AB mode provides higher resolution with stronger dynamics and improved clarity.

Dual OP-AMP x4 + BUF634A x4 | Premium Configuration Comparable to Flagship Players
Unlike many dongles that rely on all-in-one headphone amplifier chips, the Nunchaku uses a dedicated OP-AMP + BUF634A architecture commonly found in flagship audio players. The design incorporates two Raytheon tubes, four high-performance TI dual OP-AMPs and four BUF634A buffer amplifiers. This sophisticated internal structure allows the Nunchaku to deliver sound performance far beyond conventional dongle DACs.

525mW + 525mW @ 32Ω | Powerful Output Performance
In Tube mode, the Nunchaku delivers up to 525mW + 525mW at 32Ω, providing enough power to drive flagship IEMs and a wide range of headphones with ease. Despite its compact size and powerful amplification stage, power consumption remains impressively efficient at approximately 120mA / 5V in Tube mode, while Class AB mode consumes under 100mA / 5V.

Dual CS43198 Flagship DACs | Highly Regarded DAC Architecture
The Nunchaku features dual Cirrus Logic CS43198 flagship DAC chips, renowned for their excellent resolution, dynamic range, natural sound reproduction and extremely low noise floor. iBasso’s tuning expertise further enhances the performance of the dual DAC design for an immersive listening experience.

JRC Hardware Volume Control
In Tube mode, the Nunchaku utilises JRC hardware volume control. The DAC operates at maximum output while the hardware volume stage adjusts listening levels. As volume is reduced, background noise is also lowered, improving the overall signal-to-noise ratio.

0.96-Inch OLED Display & Multi-Function Knob
The Nunchaku is equipped with a 0.96-inch OLED display and a custom multifunction encoder knob, allowing users to control all functions directly from the device. An Android app is also available for additional adjustments and settings control.

PORON Suspension Design
Following extensive testing, iBasso implemented a suspended tube mounting structure using PORON material. This design helps absorb vibration and significantly reduces microphonic effects for improved sound stability.

Tube Matching with APX555 Precision Testing
Due to manufacturing tolerances inherent in vacuum tubes, minor variations can exist between units. To ensure consistent sound quality, iBasso manually matches JAN6418 tube pairs using APX555 audio analysis equipment and DINAD testing before assembly. The detailed testing process limits production capacity to approximately 50 matched tube pairs per day, ensuring high-quality audio performance.