Compact 300W DIY Audio Amplifier Board

Compact 3-channel digital power amplifier board measuring approximately 120 x 85 x 25 mm (L x W x H), weighing ~280 g. Delivers rated output of 3 × 80 W (left/right/subwoofer) and maximum output of 2 × 100 W + 1 × 120 W. Operates on AC 18–26 V input (26 V recommended). Compatible with 4–16 Ω speakers. Features low-noise circuitry with six power amplifier tubes — four for stereo channels, two in BTL configuration for subwoofer — plus two large filter capacitors and precision 1% metal film resistors. Includes dedicated potentiometers for super bass, treble, and master volume control. Designed for stable, clean audio performance at higher volumes without audible hiss or distortion. The board enables independent amplification of left, right, and subwoofer channels with tone-shaping flexibility and channel separation. Its BTL subwoofer stage enhances low-frequency headroom and control compared to standard single-ended designs. All components are selected for thermal stability and noise reduction during extended use. Ideal for compact home audio upgrades, custom bookshelf speaker builds with active subwoofer integration, desktop multimedia systems, and portable DIY speaker projects. Mounts easily using included screws; fits standard small enclosures or retrofit installations. Requires external AC power supply (not included) matched to speaker impedance and power requirements.