Four Military-grade JAN6418 Tubes: Fully Powered Tubes, MAX Performance

The PB6 utilizes four military-grade JAN6418 directly heated pentodes vacuum tubes manufactured by Raytheon implemented in a 4-channel fully balanced amplification architecture. iBasso has designed the anode power supply to deliver 22.5V voltages, providing ample headroom and a robust dynamic performance. All vacuum tubes are meticulously tested and matched by engineers using the APX555 audio testing equipment, ensuring channel consistency and exceptional sound quality. The fully balanced architecture imparts a rich, warm tube character, resulting in a natural listening experience.

Tube + Class AB Dual Output Modes: Tube Flavor & OPAMP Clarity Are Switchable

The PB6 supports both Tube and Class AB dual output modes. In Tube mode, four JAN6418 tubes serve as the amplification cores, delivering a delicate, rich, warm, and smooth sound, showcasing the exceptional characteristics of vacuum tubes. In Class AB mode, the PB6 employs a classic OP+BUF headphone amplifier circuit, utilizing four BUF634A for current amplification, offers enhanced resolution and excellent dynamic range.

8.4V High Voltage Battery Pack: Higher efficiency & Purer Power

The PB6 utilizes an 8.4V high-voltage polymer battery pack, which markedly improves power efficiency and transient response capabilities. In comparison to conventional designs powered by a single 3.7V battery, this higher voltage configuration provides a significant advantage in minimizing ripple interference typically produced by DC-DC conversion processes, thereby delivering a purer and more stable power supply. This design enables the faithful reproduction of musical nuances and dynamic range, allowing sound details to be fully expressed considerably exceeding that of other portable headphone amplifiers.

12VExternal Power Supply: Desktop-grade Performance

The PB6 supports external 12V DC power supply, which allows for a voltage swing of 24V. When connected to this external power source, the PB6's output power reaches 2300mW+2300mW@32Ω, thereby fully unlocking its driving capabilities. This enables the PB6 to effortlessly power full-size headphones, achieving performance comparable to that of quality desktop-grade headphone amplifiers.

High Precision 4-channel Volume Control NJW1195A: Providing A Perfectly Matched 4-channel Output

The PB6 is equipped with a high precision 4-channel volume control IC — NJW1195A — which offers fine adjustments with 0.5dB per step. This hardware-based volume control not only allows for precise volume control but also helps to inherently reduce background noise, resulting in a pitch-black background. This design effectively addresses the common issue of channel imbalance at low volume levels often associated with conventional carbon potentiometers. Consequently, PB6 ensures consistent left-right channel balance throughout the entire volume range, delivering a more accurate and reliable listening experience.

Selectable High & Low Bandwidth: Sound, Customized at Will

The PB6 offers two modes for the headphone output stage: high bandwidth and low bandwidth, allowing users to customize their preferred sound signature. The high bandwidth mode delivers excellent transient response, with superior control and sound resolution. The low bandwidth mode creates a softer, warmer soundstage. The seamless switching between high and low bandwidth modes caters to audiophiles' personalized listening preferences, providing more fun and enjoyment with the auditory experience.

PORON Suspension Damping: Suppresses Microphonic Effect

To suppress microphonic effects, all four tubes in the PB6 are suspended using PORON damping material, effectively isolating tube vibrations from influencing the sound quality. Additionally, a metal mesh shielding cover is installed externally on the tubes to effectively block external electromagnetic interference within specific frequency bands.

3.5mm Single-ended Input / Output + 4.4mm Balanced Input / Output

The PB6 not only offers a 3.5mm single-ended and a 4.4mm balanced outputs but also supports both 3.5mm single-ended and 4.4mm balanced inputs. This dual-interface design enables some innovative applications: it allows the source with only a 3.5mm output to be connected to the PB6, thereby achieving 4.4mm balanced output and benefiting from the high resolution and powerful dynamics characteristic of balanced headphone amplification.