ESP32 LyraT v4.3 Aux input circuit is highly confusing and surely wrong

[danak6jq]

Thank you!

Dana

[Horst Schlawutzke]

Hello there and thnks for the topic,
in order to remove the caps, would you hint me to locate them?
I can't find a pcb layout, so in the moment I am stuck.

[bobolink]

I’m interested in this topic as well.

Dana,
Does the AI-Thinker board have these parts?

Bob

[danak6jq]

Hello there and thnks for the topic,
in order to remove the caps, would you hint me to locate them?
I can't find a pcb layout, so in the moment I am stuck.

It's true the PCB has no silkscreen; fortunately, the "ESP32-LyraT Getting Started Guide" contains a link to a component layout:

https://dl.espressif.com/dl/schematics/ ... layout.pdf

Locate and remove C62, C64, C65 and C66. It is perhaps easiest to find these initially using text search in the component layout PDF.

Cheers,
Dana

[danak6jq]

I’m interested in this topic as well.

Dana,
Does the AI-Thinker board have these parts?

Bob

I can confirm that the AI-Thinker dev boards that I have, do not have these parts.

Cheers,
Dana

[danak6jq]

It's true the PCB has no silkscreen; fortunately, the "ESP32-LyraT Getting Started Guide" contains a link to a component layout:

https://dl.espressif.com/dl/schematics/ ... layout.pdf

Locate and remove C62, C64, C65 and C66. It is perhaps easiest to find these initially using text search in the component layout PDF.

Cheers,
Dana

This image may help.

https://drive.google.com/open?id=1XFEvd ... l11c7Yah-F

Cheers,
Dana

[Horst Schlawutzke]

This image may help.

Cheers,
Dana

Dana, my hero!
(probably the best answer I ever got from a forum)

regards Horst

[danak6jq]

Dana, my hero!
(probably the best answer I ever got from a forum)

regards Horst

Aw, you'll make me blush! I'm glad that I could help.

Cheers,
Dana

[nat250s]

Any update on this issue? I am now running into this problem using aux in for a project I am working with. Removal of the specified capacitors helps but doesn't eliminate the issue.

https://github.com/ns96/cassetteflow

[crosswick]

There is another pretty huge issue with the standard passthru example which also affects audio quality for some reason, and hasn't been fixed for years...

Basically the audio is only passed through the audio codec mixer and never even reaches the ESP32. This is what fixed it for me:

https://github.com/espressif/esp-adf/is ... -578473334