Douk Audio U3 PRO HiFi Mini Class A Headphone Amplifier – High-Power Desktop Amp for 18-600Ω Headphones, 1500mW Output, 3.5mm & 6.35mm Jacks, DC 5V

The Douk Audio U5 headphone amps are a compact and affordable option for those looking to enhance their audio experience. Customers have expressed mixed opinions about the sound quality, with some praising it for its clean sound and power while others have complained about the static noise and the distortion of the true sound of their vinyl records. However, most seem to agree that the amp is suitable for low impedance line level sources and can drive most headphones seamlessly. Some reviewers recommended using a higher voltage power supply for better sound quality, although the instruction leaflet advises against using anything above 20V. Customers also noted that the amp does not make any popping noise when turning on, but it may produce a static sound as it gradually pulls in the audio signal. As for the build quality, most reviewers appreciated the metal Construction and compact design, but some complained about the bright blue LED, which can be a distraction in a dark room.