Pin assignment of Phonejack LYRA TD MSC

[matti122]

It seems there is a issue with the wiring of the Phonejack connector on Lyra TD MSC. The Phonejack is connected to the differential output of the DAC1 from ZL38063. Because of this it is not possible to connect a speaker to the Phonejack.

[kewalmshah]

hi @matthias122 , we have tested LyraTD-MSC very well with the external speaker as well. Its just that you need a AUX to AUX cable to connect. Also speaker is at the output path for audio signal, hence it is connected to the DAC output

[matti122]

hi kewalmshah, thanx for fast post. The phonejack will work if you are using a mono AUX-2-AUX connection for a special reason but anyway there’s an issue with the wiring.

Refer to schematics inside ESP32-LyraTD-MSC User Guide Version 2.3, Appendix A: PhoneJack Pin 3 and 4 are fed by ZL38063_DAC1_M and ZL38063_DAC1_P respectively. Pin 3 and Pin 4 is where you connect Stereo Left & Right usually. However these 2 signals come from U8A Pin 7 and Pin 8 which is DAC1_P and DAC1_M (ZL38036) and are not the Left & Right signals but are differential + and – signals from one DAC!

I am using a mono mobile speaker for my setup with a stereo plug in but only one audio channel (mono). So this device adds both signals from the stereo plug which in fact is differential + and differential – from one DAC which in sum is zero. That is the reason why I hear nothing while you will get a signal (but only mono) on both channels.

BTW I also have the ESP32-LyraT board and this works flawlessly. The PhoneJack here is fed by ES8388_LIN2 and ES8388_RIN2 respectively which is correct and working.

[theronic]

I'm getting terribly soft and distorted audio from the 3.5mm headset mini-jack on ESP32-LYRATD-MSC despite setting correct sample rates (including resampler) on Bluetooth audio sink example. Could this be the cause?

[diimdeep]

Is this confirmed issue? is it fixed?