MH-M18/M28/M38 Bluetooth audio receiver/amplifier tear down
Published: 09 October 2021
Last updated: 05 January 2023
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