1) The import of high-grade thick FR-4 double-sided sheet, 2OZ thick copper, gold plated full-page, high-end atmosphere on the grade.

 

2) dual-mono design, the signal flow is reasonable, the path is very short, a little ground, mounted one pair per channel output power field pipe (United States new original IRFP240 \ IRFP9240)

 

3) Each channel plate dimensions: length 98mm * width 76mm * thick 2mm;

 

4) left and right channels can be independently powered, can effectively improve the channel separation, sound field restore a more clear and distinct disadvantage is the cost of increased power supply; two channels at least 500W total power transformer above, if the use of two 500W transformer Ideally separate power supply, in terms of transformer selection, more HIFI some toroidal transformer, E-type transformers flavor feet, more resistant to listen to some, R-type transformers sound clearer, more balanced, transformer secondary output voltage: Dual 18V-20V, Recommended double bridge rectifier with four-line bridge rectifier bridge recommended IR gold seal, the current capacity of 35A or so, voltage 400V-600V can, electrolytic total capacity of around 80000uF can, as far as possible choose a new filtering electrolytic, optional think Pitt, RIFA169, PHILIPS BC (blue hexagon Q grade), the United States big D, ROE, Britain and other BHC Condition good brand electrolysis, can not find a good selection of domestic Condition Jianghai CD135 is also very good, can afford the amount of inductance In 1-1.5mH, current capacity in low-frequency choke 10-12A composition CLC filter circuit, this time may be appropriate to reduce the capacitance, and the machine can be considerably flavor but also can refer to the original machine selects CRC filter circuit (see below original machine picture).

 

5) Since the PASS A5 +/- 24V DC power supply around, each output power transistor quiescent current 1.3A, so static power per channel is about 90W, two-channel static power consumption is about 180W, enough so to choose radiator ensure cooling, 10 kg more than the heat sink is necessary to ensure that the hand can touch the radiator temperature on more than five seconds is appropriate, in addition, the heat sink temperature at around 50 degrees sound ideal.

 

 

Step 1: Marked in accordance with the board in accordance with the value of all parts from low to high, from small to big, the first resistance capacitance II transistor after, then JFET, MOSFET good order of assembly welding, soldering iron JFET pay special attention to whether the leakage, For safety reasons, unplug the iron is recommended during welding JFET, sweltering with an iron welding to prevent damage JFET. After welding is completed, please carefully check the parts installed wrong or wrong pipe welding pin order, and link templates physical picture carefully than to confirm correct after adjusting P1, P2 (blue potentiometer 5K of 3296) makes and P1, P2 parallel The two ends of the resistance of 2K resistance in Europe about 500, measured with a multimeter.

 

Step 2: The board is mounted to the heat sink, remember to use the power of the insulating spacer tube and radiator insulation, insulating materials mica, alumina ceramic insulation pads, insulation cloth, thermal effects best alumina ceramic insulation gaskets, mica or if you want to cast a ceramic insulating washer thermal grease, the 4.7K NTC resistor thermal grease smeared, according to the power tube, 4.7K NTC resistor for temperature closed-loop, rapid and stable quiescent current of machine reliability is critical, can not be sloppy!

Step 3: Connect the power cable, carefully check to make sure the connection is correct, if no auto regulator, make a series 60-100W incandescent fuse in the transformer primary position, if there is a problem on the board when power is not It will be fireworks. Energized, light bulbs flashing darken, indicating circuit without fault, if the lamp is on, the circuit will have to check whether there is a fault, continue until the fault is removed energized; measurement and P1 2V profile with a multimeter, the 2K P2 parallel resistor voltage drop How much, probably starting at about 3V, if normal, continue to the next step.

Step 4: The near IRFP240 a 5K potentiometer adjustment counterclockwise circle, close IRFP9240 a 5K potentiometer adjustment clockwise circle, close IRFP240 test of parallel 2K 5K potentiometer resistor voltage drop, which in turn adjust the two potentiometers so 2K resistance voltage drop is 4V, then with a multimeter DC millivolt source file monitoring IRFP240 0.5R / 5W resistor voltage drop, two potentiometers were adjusted so 0.5R / 5W resistor voltage drop is 0.6V, output current drift midpoint about 0.1mV can.

 

Step 5: Energized about 10 minutes, re-adjusted so 0.5R / 5W resistor voltage drop is 0.6V, output current drift is about the midpoint of 0.1mV, so repeatedly, until stabilized, heat sink temperature controlled at about 50 degrees (presumably live hand to put more than 5 seconds), the best sound. Then you can connect the speaker audition enjoy the wonderful music.