ZK-MT21 Bluetooth Amplifier Board 2.1 Channel 50Wx2+100W Stereo Mini Amp | HiFi Subwoofer Audio Amplifier Receivers with Treble and Bass, BT and AUX Inputs, DC 12-24V DIY Power AMP for Home Speakers

Key features

• 【Hi-Fi Sound Quality, Customizable Audio Effects】Built with premium amp chips and optimized circuitry, the ZK-MT21 Bluetooth amplifier produces crisp highs, natural mids and rich deep bass for immersive near-field listening. Independent knobs adjust treble, bass, master volume and subwoofer frequency, so you can tailor the audio easily. It works seamlessly with most passive speakers such as bookshelf speakers, outdoor satellite speakers and car audio setups.
• 【Powerful Output, Broad Speaker Compatibility】This ZK-MT21 2.1 channel amp offers 50W×2 for L/R channels plus 100W for the subwoofer. It effortlessly drives passive speakers up to 6.5 inches (15–50W, 4–8Ω) and subwoofers up to 8 inches (20–100W, 4–8Ω). Packing strong performance in a tiny form factor, it’s perfect for speaker upgrades, DIY audio builds, compact soundbars and projector or small TV audio systems. It breathes new life into vintage home theater speakers too.
• 【Bluetooth 5.0 & Plug-and-Play AUX Input】The ZK-MT21 home stereo amplifier receiver comes with stable Bluetooth 5.0 for fast, seamless wireless pairing with your phone, tablet or laptop. It reaches up to 39 ft (10 m) and supports auto-reconnect to previously paired devices. For wired audio, just plug into the 3.5mm AUX port for simple plug-and-play use.
• 【12–24V DC Wide Voltage Input】This ZK-MT21 mini audio amplifier works with 12V–24V DC power supplies. Use a wall adapter (15V 6.33A or 19–24V 5A+ recommended), or a 20V drill battery for portable builds. Higher voltage delivers more stable power, stronger output and better sound quality. A low-ripple power supply also helps cut unwanted background hiss.
• 【Compact Form Factor & Multi-Protection for DIY】Measuring only 3.54 × 3.7 × 0.87 inches, the ZK-MT21 power amplifier fits perfectly for home audio, small parties, portable DIY speakers and car audio upgrades. It includes built-in over-voltage, under-voltage, overheat and short-circuit protection to keep your setup safe and running reliably.