HIFI CDM12 clock PCB empty board CD clock DIY empty board, excluding electronic parts
Product Description :
CDM12 clock board can also be used to improve the clock of other CD players, the effect is obvious!
In order to satisfy some fans who like to do it themselves. The component specifications have been printed on the board surface, no additional drawings, thank you!
IC uses a single op amp, this shop uses the ultra-low noise AD797, you want to save money can use 5534 can also work properly. Three electrolytic capacitors can be used for CD1 with 47-220uf, CD2 with 22~68uf, and CD3 with 10~47uf. Q1 uses the commonly used low power NPN transistor, the shop uses 2N2222A. T1 uses L7812. There are also 2 small patches 0805 on the back, which are 1 ohm resistors in parallel. If they are not found, they can be connected directly.
The crystal oscillator can freely choose the temperature compensation or the ordinary active crystal oscillator. I suggest that if you do not buy the best temperature compensation, (40 yuan to 90 yuan), use ordinary active. Pingyi Wenbu did not have much improvement in the workmanship, just selling a hoe. As the coaxial output board of our store said, why not use an audio transformer? Because cheap transformers can damage the sound quality, many veterans know. Not to save the transformer money, if you go with dozens of audio transformers of a hundred dollars, then you lose the price.
The power supply can be selected from 15 to 24V. The recommended value is 18V.
Note: After installing all components, do not install crystal oscillator, adjust the adjustable resistor to make the output reach the voltage requirement of your crystal oscillator, generally 3.3V or 5V. After the voltage is normal, reinstall the crystal oscillator, and then try to measure the voltage. It will be 0.xV lower and adjust it back. If you replace a different op amp, just in case, please be sure to disconnect the crystal power supply (remove the inductor and disconnect it) and re-adjust the voltage.
The parts on the picture are only for display, The actual shipment is an empty board. You need to purchase additional parts yourself to install. All you buy is an empty printed circuit board, you must pay attention!
As different computer display the colors differently,and the color maybe is little difference from the actual items,but we can guarantee the style is same,but maybe some not same performance on different bodies as on the models.Hope you can understand it.thank you！
US, Australia, New Zealand: 2~3 weeks France: 2~4 Weeks
UK, Germany, Canada: 3~5 weeks Other European Countries: 3~5 Weeks
Asian Countries: 3~5 Weeks Others: 3~8 Weeks·
Items will be shipped in within 4 days after payment is received.
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