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Printed Circuit Board Project
1¡¢The PCBs sold in the store do not contain any components, and you should prepare them by yourself.
2¡¢To complete this project, high level knowledge of electronics and rich experience in terms of soldering and testing are required.
3¡¢Due to time zone and language communication restrictions, we can only provide limited technical support, and you need to solve problems by yourself.
4¡¢ We do not provide information other than the product introduction page.
MOFI-JLH2003 Single-End Class A Power Amplifier PCB Project
It is based on the core circuit of the JLH2003 Power Amplifier.
Tech highlights:
Fully Discrete .
Single-End Class A.
Monarual design.
single-point grounding, ground resistance is close to the 0.02 ohm, low noise design.
PCB is small and flexible, very friendly for all kinds of chassis installation.
More cost-effective sound modification potential.
total 4 Power Transistors per channel for power output.
Maximum input voltage£º3.8VPP
Gain: 11X
input resistance: 47K
Output Power: Class A 8Wate 8¥Ø
Recommend to use CRC filter after rectifier.
Schematic & key point of debugging
PCB comes with component parameters for easy installation.
We only refer the schematic of the amplification part of the circuit. If you need full circuit parameter, please read the component value with the PCB by yourself; we do not provide additionally.
please keep test point voltage close enough to it, +-20% is also permitted.
Instructions
Since the PCB holes are plated through, you only need to solder the parts from the bottom of the board. Do not drill or enlarge the holes because that would damage the through-plating.
Clean both sides of the blank PCB with paper towel and isopropyl alcohol or electronics flux remover, then solder the components to the board, starting with the lowest profile parts.
Make sure the correct part goes into each position on the circuit board. Measure each resistor with your multimeter to ensure it`s the proper value.
Clean up the solder flux residue from the board with isopropyl alcohol (or electronics flux remover) and a brush.
Inspect all solder connections carefully, using a magnifying glass, to make sure there are no solder bridges or cold solder joints. Use a multimeter in ohms scale to check for short circuits. As a minimum, you should verify that the V+ and V- DC inputs are not shorted to ground, or to each other, and that the output pad isn`t shorted to ground. Correct any mistakes before proceeding to the next phase.
Tips:
please prepare external heatsink.
Adjust 100R-VR clockwise to the maximum resistance value before powering on.
After power-on, slowly adjust 100R-VR counterclockwise until 110mV can be measured between TP-a&C,TP-a&D,TP-b&E and TP-b&F.