Four military grade jan6418 tubes the pb6 macaw utilises four military grade raytheon jan6418 directly heated pentode tubes in a fully balanced, 4 channel amplification design. Its custom 22.5v anode power supply delivers exceptional headroom and dynamic authority, while each tube is meticulously tested and matched using apx555 equipment to ensure perfect channel balance and consistency. The result is a rich, warm, and natural tube sound, powerful yet effortlessly musical. Higher efficiency purer power the pb6 is powered by an 8.4v high voltage polymer battery pack, boosting efficiency and transient response. Compared to standard 3.7v designs, it reduces ripple interference from dc dc conversion, delivering purer, more stable power for faithful reproduction of musical nuances and exceptional dynamic range, far beyond typical portable headphone amps. High precision 4 channel volume control the amp is equipped with a high precision 4 channel volume control ic mdash njw1195a mdash 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. Pb6 ensures consistent left right channel balance throughout the entire volume range, delivering a more accurate and reliable listening experience. Desktop grade performance pb6 macaw 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 2300mw2300mw32omega, 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. Tube class ab dual output modes 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 opbuf headphone amplifier circuit, utilising four buf634a for current amplification, which offers enhanced resolution and excellent dynamic range. Customisable sound tailor your sound with two selectable output stages high bandwidth and low bandwidth, allowing users to customise 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' personalised listening preferences, providing more fun and enjoyment with the auditory experience. Poron suspension damping 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. Inputs outputs the pb6 not only offers 3.5mm single ended and 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.