{"product_id":"arrarown-zk-as21-bluetooth-5-1-2-1-class-d-amplifier-board-220w-2-350w-sub-usb-aux-tone-controls","title":"ARRAROWN ZK-AS21 Bluetooth 5.1 2.1 Class D Amplifier Board — 220W×2 + 350W Sub, USB\/AUX, Tone Controls","description":"\u003cp\u003e\u003cstrong\u003eThe ARRAROWN ZK-AS21 is a compact 2.1-channel Class D amplifier module that delivers 220W to each stereo channel and up to 350W to a powered subwoofer, plus Bluetooth 5.1, USB and AUX inputs for flexible home audio use.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eWhether you are upgrading passive bookshelf speakers, building a compact powered subwoofer, or creating a DIY home theater, the ZK-AS21 combines high output, modern wireless connectivity and onboard tone controls in a small footprint. It uses efficient TPA3255 class D amplifier chips and multiple protection features to support speakers rated 30–220W (3–8Ω) and a subwoofer up to 350W (2–8Ω). The board accepts DC 16–38V and benefits from higher supply current for peak output, while an ultra-silent cooling fan helps maintain reliability during heavy use.\u003c\/p\u003e\n\n\u003ch3\u003eHow does the ZK-AS21 handle speaker power and impedance?\u003c\/h3\u003e\n\u003cp\u003eThe amplifier supplies two high-power stereo channels and a dedicated sub output with separate volume and frequency adjustment. It’s designed to drive medium- to high-power passive speakers and a dedicated subwoofer when paired with an appropriate power supply.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eLeft\/right channels: 220W per channel (dependent on supply voltage\/current and speaker impedance).\u003c\/li\u003e\n  \u003cli\u003eSubwoofer channel: up to 350W output (2–8Ω compatible).\u003c\/li\u003e\n  \u003cli\u003eRecommended speaker range: 30–220W for satellite speakers; subwoofer 30–350W.\u003c\/li\u003e\n  \u003cli\u003eRequires DC 16–38V power; higher voltage\/current increases available output (use supply rated above amplifier working power).\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat connectivity and controls are available for daily listening?\u003c\/h3\u003e\n\u003cp\u003eMultiple input options let you connect smartphones, USB sticks, PCs, or a wired audio source. Onboard tone and crossover controls allow quick adjustments so the system matches room acoustics and personal taste.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eBluetooth 5.1 for wireless streaming with improved range and stability (approx. 15 m \/ 49 ft).\u003c\/li\u003e\n  \u003cli\u003eUSB flash playback and USB sound card input for direct digital sources.\u003c\/li\u003e\n  \u003cli\u003e3.5mm AUX for wired devices; switchable from Bluetooth to AUX.\u003c\/li\u003e\n  \u003cli\u003eIndependent Treble\/Bass knobs plus sub volume and 20–200Hz sub frequency adjustment for precise tuning.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat technology and protection features improve sound and durability?\u003c\/h3\u003e\n\u003cp\u003eThe ZK-AS21 integrates modern amplifier ICs and low-noise preamps to keep distortion low and clarity high, while built-in protections guard the module and connected speakers. Cooling and circuit safeguards extend usable life under demanding conditions.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eDual TPA3255 class D chips for efficient, high-definition output and low distortion.\u003c\/li\u003e\n  \u003cli\u003eSix low-noise 5532 preamplifiers to boost signal quality and gain performance.\u003c\/li\u003e\n  \u003cli\u003eProtections: over-voltage, under-voltage, over-temperature, and short-circuit protection.\u003c\/li\u003e\n  \u003cli\u003eLong-life, ultra-silent cooling fan and covered case to assist heat dissipation and component safety.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow do I power and install the ZK-AS21 in my setup?\u003c\/h3\u003e\n\u003cp\u003eInstallation is straightforward for anyone comfortable with speaker wiring and DC power supplies. Choose a power supply that meets or exceeds the amplifier’s voltage\/current needs and observe speaker impedance recommendations for safe operation.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003ePower input: DC 16–38V; recommended supply current 10A or higher depending on desired output.\u003c\/li\u003e\n  \u003cli\u003eConnect two passive speakers to stereo outputs and a passive or active subwoofer to the sub output accordingly.\u003c\/li\u003e\n  \u003cli\u003eUse shielded audio cables for AUX\/USB connections to reduce noise; disconnect Bluetooth when using AUX if required.\u003c\/li\u003e\n  \u003cli\u003eMount the module in a ventilated enclosure and keep the fan intake unobstructed for best thermal performance.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for? The ARRAROWN ZK-AS21 is aimed at audiophiles and DIY builders who want a compact, high-output amplifier board for custom speaker systems or small home theaters. It suits users comfortable with basic wiring and selecting a compatible DC power supply who seek Bluetooth streaming, precise tone controls and high-efficiency Class D power for clean, loud playback without a bulky chassis.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: What power supply does the ZK-AS21 need?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Use a DC supply rated 16–38V with sufficient current (10A or higher recommended) matching desired output.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Can I stream audio via Bluetooth and use AUX at the same time?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: The module supports Bluetooth 5.1 and AUX, but switch to AUX after disconnecting Bluetooth to avoid source conflicts.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"ARRAROWN","offers":[{"title":"Default Title","offer_id":48423751712925,"sku":"B0DDPH2HVP","price":74.21,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0766\/9596\/1757\/files\/arrarown-front-panel_5ac40569-262c-4dfb-bf36-2c8807092d98.jpg?v=1781365419","url":"https:\/\/nexoltic.com\/products\/arrarown-zk-as21-bluetooth-5-1-2-1-class-d-amplifier-board-220w-2-350w-sub-usb-aux-tone-controls","provider":"Nexoltic","version":"1.0","type":"link"}