Primare-A20_MKII-pwr-upg 维修电路原理图.pdf

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1、How To Update A20 From MKII To MKIII Make sure the amplifier is not connected to the mains. Take the top-cover off the amplifier. Locate and change the following components: R5, R105 to 280R R1, R101 to 380R R2, R4 to 7,5K R36, R136 to 620R C19, C119 to 470pF The seize is either 0805 or 1206 dependi

2、ng on the age of the amplifier. The pictures is applying on 0805. On the 1206 variant they are located a bit different, check Service Manual. After this is done, power up the amplifier and check that it works. Power it off and remove the two Shortlinks on the board, power it up again and let it be w

3、arm. (Just let it run without any signal for half an hour). Measure the bias on the pins where the shortlinks where located, you should adjust it With the potentiometer to 13mVon each channel. Recheck after another half an hour. Power it off and refit the shortlinks. Refit the cover. Now you are don

4、e! RadioFans.CN 收音机爱 好者资料库 Overwiev of the A20 Bias Trimmer Left Channel Shortlink Left Channel Shortlink Right Channel Bias Trimmer Right RadioFans.CN 收音机爱 好者资料库 Close Look Right Channel Temporarily remove the heatsink on REG2 R4 C119 R101 R136 Close look Left Channel /Bjrn Holmqvist Primare Systems AB C19R1R5R105