This device is a class d amplifier. Manufactured by Audison and its model SR1DK is produced in Italy. They are good circuits and they don't get damaged easily unless the wrong sub is connected to the output of the circuit. I prepared this video last week and was waiting for the owner of the device to confirm the purchase of mosfet. He has not responded so far. For this reason, I have prepared a video of the route before placing the MOSFETs. If I can buy the MOSFETs, I will continue the video. If the owner of the device is not satisfied, I will return the device. The MOSFETs of this circuit must all be the same and preferably from the same brand. It is better to replace all MOSFETs. Since the switching in class d is different from class ab, the type of operation of the circuit is also different in the sound section. In the voltage conversion section (class d and class ab) both circuits are the same. In class ab, the sound signal is amplified in an analog way and reaches the base of the positive pnp and negative npn transistor. But in class D, this signal is modulated on a square wave or pwm and then reaches the output MOSFETs. The audio signal is separated from the square wave before the sound output MOSFETs with the help of an LC filter. Efficiency is higher in class D and it has less noise. MOSFETs are only active when an audio signal enters the circuit, but in class ab power transistors are always on. In this video, I compared and explained how Class D amplifier works with Class AB. How class D amplifier works: • Setting up MOSFET in circuits where the voltage... ------------------------------- ------------------- Financial support link connected to Shapark portal: https://zarinp.al/golmrezadarvishy -------------- ----------------------------------- Financial support link for loved ones abroad: https://paypal.me /MLavaei?country.x=I... ---------------------------------------------------- ------- Car amplifier training course - Instructor: Gholamreza Darvishi https://elecma.ir/product/%d8%af%d9%8... ----------------------------- ----------------- How does a car amplifier work: • How does a car amplifier work? ... Noise in the amplifier: • Noise removal filter in the car amplifier • Why is there noise in the amplifiers on the speakers... DC offset in the amplifier: • What does DC offset mean in the amplifier? ... Repairing a broken amplifier: • How to repair a car amplifier... Bass sound in a home amplifier: • Repairing a home amplifier.. Audio device... ------------ ---------------------------- Click on the following link to subscribe to this channel: / @electronic4hame for subscription. Click on the following link on my English channel: / @electronic4u-david ----------------------------------- -- Thank you for your support ❤️❤️❤️ of our website for preparing courses https://www.elecma.ir Our training courses include 1) analysis of switching power sources based on circuit and schematics 2) analysis of electrical protection circuit board on the map and description of circuit working principles 3) analysis of computer power circuit. Complete analysis of 4 different maps with existing types of ICs 4) Construction of variable power supply with high and low current (with matching transistor 5) Installation of flash player in the car broadcast in principle along with the construction of the signal circuit without change in the broadcast circuit 6) Review and analysis of car battery charger circuit 7) Scientific and practical examination of welding inverter or welding machine 8) Car amplifier training course 9) 220 volt power inverter training course 10) Changing the bee-book power supply to the construction of a short circuit 11) Basic concepts in electronics (scientific and practical application) Our website for preparing courses https://www.elecma.ir 00:00 Open the device 02:35 Audison Class D amplifier initial test 08:54 Replacing burnt MOSFET 14:02 Turning on the circuit without MOSFETs 16:36 Displaying the waveform without placement MOSFETs 18:52 Using lighter gas for troubleshooting