Author Topic: Chinese TDA7377 2.1 Amplifier Kit  (Read 1067 times)

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Offline Harvey17Topic starter

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Chinese TDA7377 2.1 Amplifier Kit
« on: December 05, 2019, 09:54:47 pm »
I've just put together one of these little Chinese kit TDA7377 amplifiers - https://www.aliexpress.com/item/32804621834.html

All working quite well considering, however there is quite a loud THUMP on the subwoofer at switch on. The datasheet for the TDA7377 states the chip has silent turn on/off, so I'm guessing the cause is the offset of the NE5532 used as a pre-amp for the subwoofer section.

So, simple question is - any suggestions as to how to get rid of this? Are there any suitable opamps to replace the NE5532 with 0-offset? Am I missing some simple way of fixing this problem?



:o
 

Offline magic

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Re: Chinese TDA7377 2.1 Amplifier Kit
« Reply #1 on: December 05, 2019, 11:17:49 pm »
Maybe there is some shutdown pin on the chip amp which could be used to keep it disabled for a moment after power on?

Another thing is that this TDA7377 may not actually be a TDA7377 and the NE5532, by the looks of it, most likely is not an NE5532 ;)
 

Offline SiliconWizard

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Re: Chinese TDA7377 2.1 Amplifier Kit
« Reply #2 on: December 06, 2019, 03:06:21 pm »
Looking at the TDA7377 datasheet (assuming the one on this board is genuine), there's a "stand-by" pin (pin 7). To delay the power-on of the amp, you'd need to connect it to the power supply through an RC network. Check what this pin is connected to on the board.
 


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