Black Pearl is a project introduced after three years of the Moonlight's evolution. Its intention was to create a headphone amplifier with at least equal sound quality followed by much higher output power, enabling the amplifier to work well also with hard to drive high impedance dynamic and orthodynamic headphones. Besides higher power the Black Pearl has got another advantage over Moonlight which is high tolerance for supply voltage fluctuations in a broad range. This let us introduce the dedicated NiMH battery for Black Pearl, providing clean supply voltage for up to 40 hours without charging. The battery has got two sockets for connection with the amp and the charger simultaneously. You can continue listening to the music when the battery is empty charging it at the same time. The charger is based on a linear power supply which will not deteriorate sound quality like a switched mode power supply would do.