Description

Visit store Items for sale About us Product Details Description: End of ultra low noise electret microphones pre-amp amplification board, using ST imported K472 electret microphones special amplifier chip, chip with low noise. Gain adjustable, power supply wide,and can be difference output, can also be single-ended output. Gain adjustment: resistance R3 is gain adjustment resistance, when the default delivery is 30 db (resistance to 1 k), if not appropriate, can consult the table below change R3 resistance to obtain different gain, changes the resistance when the need to take off the original R3 SMD resistor (if you feel bad patch welding, welding the R3 can also use the plug-in beside two reserved welding plate above (gain is 0 to 40 db variable). Microphones connected: microphones positive + and negative -, GND on the board as a shield, don't need connected microphones (also can not meet, meet, but it is better to avoid interference) Output connection: 1: difference Output: connect signal +, -, middle is GND grounded. 2: single-ended output: connect signal +, middle GND connect grounding 3: Dual -channel output : signal +when a channel, signal - when a track, GND grounding in the middle Three kinds of output connection can choose according to need Operating voltage: DC 2.3 v to 5.5 v The board size: 25 mm * 20 mm Note: the board power supply had better not use the switch power supply, otherwise the low noise, interference may be serious. Package included: 1PCS K472 Low Noise Electret Microphones Amplifier Board For Differential Single-Ended Output Payment Method Shipping Policy Returns & Refund Policy Feedback Payment Method EBAY Managed Payment. But we only Accept your Ebay Address , please Make sure it's 100% right. Payment must be received in 5 business days of auction closing. Please leave note for your special request (e.g. Colors or Size) in PayPal when you pay the order. Any special request cannot be accepted after 24 hours of payment, because most of orders will be processed instantly and same day dispatched. Shipping Policy 1. We only ship to the confirmed address provided by eBay. please make sure your ebay address is 100% matches the address you would like us to ship to. If not, please let us know before we sent you the package, or we will not be responsible for any loss. hope you could understand. 2. Orders will be processed instantly and dispatched within 1-3 business days except hoilday, so we do NOT accept any email/message note after you place orders. 3. All package need to wait 30 days,Please take care it.Less than 30 days,we can't take a refund. Returns & Refund Policy All package need to wait 30 days (US only n eed 7-10 days) , Please take care it.Less than 30 days,we can't take a refund . If the item is defect when you receive it or you are not satisfied with it, please return it within 14 days for a replacement or money back. But the items must be back in factory condition. Please keep in touch with us and double check the return address before you return it. If is item is defective in 12 months, you can return it to us. We will send you a new replacement after receiving the defective item. Feedback We maintain high standards of excellence and strive for 100% customer satisfaction! Feedback is very important to us. We request that you keep in touch with us immediately BEFORE you give us neutral or negative feedback, so that we can satisfactorily address your concerns.