Headphone amplifier with Microe LM4811 click board

Hardware
1

Hello to all zynthianers !

Just have recieved micro electronica headphone amp click board with lm4811 to add a high quality headphone output to the new zynthian. Can’t figure out how to connect it properely to GPIO to make it work.

photo_2025-07-08_14-11-27
photo_2025-07-08_14-11-27721×1280 143 KB

photo_2025-07-08_14-11-20
photo_2025-07-08_14-11-20721×1280 123 KB

The company producing the board says it can be controlled directly but there is no proper manual or instruction what pins have to be connected to GPIO to make it work. It suppose to be connected to Rpi via special microbus board adapter. But standalone operation is also announced.

There are only 3 active pins on the board except ther power pins: CLK (I assume clock), U/D (volume regulation) and RST (reset pin).

Did anyone here had an experience with this or similar LM4811 board connecting it to zynthian with successfull result.

Please help ! The support of Microe doesn’t respond yet…

2

Hi @dhrupadiya - here’s the datasheet on the LM4811:

It provides basic info on the chip itself, see page 12 - APPLICATION INFORMATION.
Hopefully the board manufacturer provides a schematic, or you can figure out what board pins correspond to the chip’s pin numbers from the board itself.

2 Likes
3

Thia is only for small low-impedance earbuds or very small speakers.
With increasing headphone impedance – good headphones are often higher than 60Ω, some even 600Ω or more – , this device gives dreadful performance. It would be a regression even from existing V5 design.
Make an NE5534 headphone amp, or even one with discrete transistors! It is not that difficult!

2 Likes