Description:  This is a kit parts. You should solder it by yourself.    Features:  1. High sensitivity;  2. Low power;  3. Wide operating voltage range;  4. Low power consumption;  5. DIY design;  6. Colorful display;  7. Mode adjustable;    Parameter:  No. Parameter Value  1 Model: ASD-84;  2 Standby current: Less than 1mA;  3 Soldering difficulty Level: Easy;  4 Working voltage: DC 5V;  5 Display LED: 8*4;  6 Display color: Red+Blue;  7 LED Size: 2*5*7;  6 PCB Size: 94*39.5mm;    Instructions:  Step 1: Complete the installation in the normal way following installation manual and schematic. (Please request separately).  Step 2: Connect audio;  Step 3: DC 4-9V voltage;  Step 4: Adjust the working mode;  Step 5: Test and use.    Mode setting:  Mode Set Method Remarks:  Factory Testing Mode Press button S1 before Power on It is used to detect all LED whether can be ON;  Fast Flashing Mode(3) Short press S1 less than 1second The refresh frequency is very fast;  Medium Flashing Mode(2) Short press S1 less than 1second The refresh frequency is general;  Slow Flashing Mode(1) Short press S1 less than 1second The refresh frequency is slow;  High Sensitivity Mode(H) Long press S1 more than 2second It can detect weaker audio signals;  Medium Sensitivity Mode(B) Long press S1 more than 2second It can detect general audio signals;  Low Sensitivity Mode(L) Long press S1 more than 2second It can filter more interference audio signals;    Using attention:  1. Please make sure all the components in the right direction and right place.  2. Please check whether pseudo/float welding. This is very important.  3. The soldering iron can't touch the components for a long time, otherwise, the components will be damaged because of the high temperature.  4. It is recommended to use a stable power supply, otherwise, it may interfere with the audio signal output.    Component list:  NO. Component Name PCB Marker Parameter Quantity:  1 Metal Film Resistor R15 10ohm 1;  2 Metal Film Resistor RX1-RX4,RY5-RY12 47ohm 12;  3 Metal Film Resistor R13-R14 470K 2;  4 Ceramic Capacitor C5 0.001uF 102 1;  5 Ceramic Capacitor C2-C4 0.1uF 104 3;  6 Electrolytic Capacitor C1 220uF 1;  7 Red LED D1-D16 2*5*7mm 16;  8 Blue LED D17-D32 2*5*7mm 16;  9 Audio Socket J2,J3 SMD3P 2;  10 Power Socket J1 DC3.5 1;  11 WD1084 U1 DIP-16 1;  12 Button S1 6*6*5 1;  13 USB to DC Cable;  100cm 1;  14 Audio Cable;  100cm 1;  15 PCB ASD-84 94*39.5mm 1;    Application:  1. Electronic teaching;  2. Exercise soldering skills;  3. Circuit application;     Frequency asked questions:  1. Why can't work?  A: Please make sure all components in the right direction and right place and check whether pseudo/float welding. This is very important.     Install tools you need preliminary preparation by yourself:  1>. Soldering iron;  2>. Multimeter;  3>. Solder wire;  4>. Iron stand;  5>. Diagonal cutting pliers;  6>. The screwdriver;  7>. Tweezers;  8>. Long nose pliers;  9>. Suction tin;  10>. Cleaning sponge;  11>. Screwdriver set.