The RPX-33 dual mono topology headphone amp from Rudistor Sound Systems of Italy, uses a mixture of clean, optimized and pure audiophile electronics to deliver the finest sound available. Its sleek design, built to match the Ultrasone Limited Edition 9 headphone, ensures the ultimate audiophile experience. The RPX-33 was designed to provide the listener with high transparency, real life soundstage, deep and full bass and refined mid-highs, with astonishing dynamics, and absolutely crystal clear sound. The electronic design for the RPX-33 was precisely calculated and very cleanly implemented to ensure the shortest signal path, a must in the audiophile world. The power supply uses a capacitance multiplier to deliver pure DC power for that pure sound and black background.