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MH-M18/M28/M38 Bluetooth audio receiver/amplifier tear down

Published: 09 October 2021

Last updated: 05 January 2023

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The MH-M38 is a stereo audio receiver with loudspeaker outputs which can play music from a smartphone wireless via Bluetooth.

MH M38 Bluetooth audio receiver circuit redesigned

Because I wanted to miniaturize this module for my electronic larynx, I have redesigned it.
You can download the newest version of the schematic at GitHub.
MH M38MH M38 Bluetooth audio receiver schematic
Questions about the design

The resistor R2 is superfluous, I dont know why it is used.
The TC8871 can be turned off by making pin 1 high. These 2 pins are connected to the MH-M38 pin 18, but this is constant 0V. So it makes no sense.

MH-M38 tear down in progress

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