> **Source:** Core Electronics is an Australian maker-electronics retailer and manufacturer based in Newcastle, NSW, run by a team of makers and educators. We design and manufacture our own product lines (PiicoDev, CE originals) and are official retailers for iconic maker and industrial brands including Raspberry Pi, Arduino, Adafruit, SparkFun and DFRobot. Orders ship Australia-wide from our Newcastle warehouse. Prices are in AUD and include GST. Pricing, stock and dispatch on this page are generated from the store's live catalog. Full machine-readable index: https://core-electronics.com.au/llms.txt # Stereo 3.7W Class D Audio Amplifier - MAX98306 **Type:** Product page · **SKU:** ADA987 · **Brand:** [Adafruit](https://core-electronics.com.au/brands/adafruit-australia) **Page:** https://core-electronics.com.au/stereo-3-7w-class-d-audio-amplifier-max98306.html ([markdown](https://core-electronics.com.au/stereo-3-7w-class-d-audio-amplifier-max98306.html.md)) This incredibly small stereo amplifier is surprisingly powerful - able to deliver 2 x 3.7W channels into 3 ohm impedance speakers. Inside the miniature chip is a... ## Pricing - **Price:** $16.35 (inc GST) — $14.86 AUD, exc GST - **Quantity discounts:** 10+ $14.42 (exc GST) · 50+ $14.12 (exc GST) ## Availability & dispatch - In stock, ships same business day if ordered before 2PM (Australia/Sydney). - We can dispatch 2 today, and up to 500 more in 8–12 days. ## How to buy - **Build a cart:** compose `https://core-electronics.com.au/cart/link?items=ADA987:1` (comma-separated SKU:qty pairs) and share the link. Opening it shows a confirmation page with live pricing and stock before anything is added to the cart. - **Verify the cart first:** fetch `https://core-electronics.com.au/cart/link/ADA987:1.md` for live line prices (inc & exc GST, quantity discounts applied), stock and dispatch estimates, and totals. Append `/to/{AU-postcode}` (or `/to/{country-code}:{postcode}`) before `.md` for delivery options and prices to that destination. Unknown, retired, or out-of-stock SKUs are flagged. (Query form `cart/link.md?items=...` also works but some robots parsers refuse query strings here.) - **Checkout** is completed on-site and includes a captcha at the payment step. Share the cart link; checkout takes it from there. - **Search the catalogue:** `https://core-electronics.com.au/search/{query}.md` (URL-encode the query; pages 2-3 at `search/{query}/{page}.md`; `search.md?q=` also works) - **Payment methods, purchase orders, policies and contact details:** https://core-electronics.com.au/llms.txt ## Description This incredibly small stereo amplifier is surprisingly powerful - able to deliver 2 x 3.7W channels into 3 ohm impedance speakers. Inside the miniature chip is a class D controller, able to run from 2.7V-5.5VDC. Since the amp is a class D, its incredibly efficient (over 90% efficient when driving an 8O speaker at over a Watt) - making it perfect for portable and battery-powered projects. It has built in thermal and over-current protection but Adafruit could barely tell it got hot. This board is a welcome upgrade to basic "LM386" amps! The inputs of the amplifier go through 1.0uF capacitors, so they are fully 'differential' - if you don't have differential outputs, simply tie the R- and L- to ground. The outputs are "Bridge Tied" - that means they connect directly to the outputs, no connection to ground. The output is a 360KHz square wave PWM that is then 'averaged out' by the speaker coil - the high frequencies are not heard. All the above means that you can't connect the output into another amplifier, it should drive the speakers directly. Comes with a fully assembled and tested breakout board with 1.0uF input capacitors. They also include header to plug it into a breadboard, 3.5mm screw-terminal blocks so you can easily attach/detach your speakers, and a 2x4 header + jumper to change the amplifier gain on the fly. You will be ready to rock in 15 minutes! **Speakers are not included, use any 3ohm or greater impedance speakers.** - Output Power: 3.7W at 3O, 10% THD, 1.7W at 8O, 10% THD, with 5V Supply - Passes EMI limit unfiltered with up to 12 inches (30 cm) of speaker cable - High 83dB PSRR at 217Hz - Spread-Spectrum Modulation and Active Emissions Limiting - Five pin-selectable gains: 6dB, 9dB, 12dB, 15dB and 18dB. Select with a jumper or by setting the G and G' breakout pins (see [schematic for breakout board showing gain pin settings](https://core-electronics.com.au/attachments/localcontent/MAX98306schem_284775db8dc.png) for details) - Excellent click-and-pop suppression - Thermal and short-circuit/over-current protection - Low current draw: 2mA quiescent and 10uA in shutdown mode ## Technical Details [Datasheet, schematic, and Fritzing library available in the product tutorial](https://learn.adafruit.com/stereo-3-7w-class-d-audio-amplifier/downloads) Dimensions (without 0.1" header): - Length:28.25mm/1.11in - Width:24.15mm/0.95in - Height:3.03mm/0.12in - Weight:2.33g ![](https://core-electronics.com.au/attachments/localcontent/rohs_icon_8216055e11.jpg) ## Guides for this product - [How to Use Speakers and Amplifiers with Your Project](https://core-electronics.com.au/guides/analogue-electronics/how-to-use-speakers-and-amplifiers-with-your-project/) ## Videos for this product - [How to Use Speakers and Amplifiers with Your Project](https://core-electronics.com.au/videos/how-to-use-speakers-and-amplifiers-with-your-project) ## Images - [Product image 1](https://core-electronics.com.au/media/catalog/product/9/8/987-00.jpg)