Douk Audio A5 PRO TPA3255 Bluetooth HiFi Class D Stereo Amplifier Review

The Douk Audio A5 PRO is a compact class-D stereo power amplifier priced at $114.99. It builds on the base A5 with upgraded Bluetooth 5.1 connectivity including a reset button, bass and treble knobs, and a headphone output, positioning it as a flexible centerpiece for a desktop or small living-room system.

Power comes from TI's TPA3255 chip, with a maximum output of 300W x 2 into 4 ohms and support for 4-8 ohm passive speakers. The design uses Post-Filter Feedback (PFFB) technology and a 4-layer immersion gold PCB, which Douk Audio says reduces distortion, improves frequency response and manages heat effectively; the measured THD+N is 0.003% and SNR is 113dB or better. Premium parts include Rubycon and WIMA capacitors. Working voltage is DC 24-48V, so the output you get depends on the 32V/5A or 48V/5A adapter variant you choose.

Inputs are Bluetooth 5.1 or stereo RCA, and the amp drives banana speaker jacks, a 3.5mm AUX output and a 3.5mm headphone jack rated 500mW at 32 ohms for headphones from 16-600 ohms. All three outputs play at the same time and share the same volume, treble and bass controls. The tempered glass access panel on top lets you swap the two pluggable NE5532 op-amps for dual types such as 2134, 2604, 5532, 2068 or Muse02 without disassembling the unit, and adjustable internal LED lighting plus a transparent panel round out the futuristic look.

Douk Audio ships worldwide with free and expedited shipping options at varying cost by country. Packages under 2kg travel by airmail in roughly 10-25 days, while orders over 2kg ship via DHL/UPS/FedEx in about 5-8 days, and any import duties or customs charges are the customer's responsibility. Returns are free within 30 days for a full refund, and every item carries a 1-year warranty. Exclusions cover orders placed by mistake, man-made damage or misuse, a change of mind, and anything outside the warranty terms.