Four ways audio input switching DIY kit AC 9V-13V Electronic key version

Product Description : Voltage: AC 9~13V Size: 95mm*53mm*27mm Kit including: PCB board *1 Three Terminal Block*5 Two Terminal Block *2 Relays*4 (removed from other machines) 2N5551*4 LED light-emitting diode*4 ST4017*1 7812 Regulators IC*1 Round bridge rectifier*1 Electrolytic capacitor 100UF*1 0.47uF film capacitor*1 16-pin IC socket*1 2.2K resistor*1 10K resistor*5 Test switch*1 1N4148 diode*4 0 ohm resistor*1 Wiring Instructions*1 Note:this is a kit only. all component included but not weld on the pcb board. buyer weld the components on the pcb board as fun for DIY. This is amplifier for DIY fun. only for professional. all information has already printed on the pcb board such as where to connect the in and output power, where connect the speaker. if you do not know how to assemble components or cannot read the pinpoint on the pcb board, we suggest you google more information before you buy. this will save a lot of money and time for you.