[Wagg]

Hello,
I use latest kodi and latest Netflix addon in my nvidia shield.
Sound is going to my old amp through optical, and there is no sound in passthrough mode. Without passthrough mode, I cannot hear the voices.
I would like to find a workaround for getting dolby digital instead of dolby digital+
Thank you

You need to go into Kodi System settings/system/audio, change number of channels to 2.0, then go down to Enable Dolby Digital (AC3) transcoding and turn it on.

... and also mix stereo to multichannel otherwise it doesn't work.

Just a question, does it affect the sound natively in dts or dolby digital?

May I understand that using passthru mode:
When signal is in dd+ or pcm it is processed to get 5.1 dolby digital
When the signal is already in dts or ac3 there is no processing it is really a passthru
?

You don't need to mix stereo to multichannel- at least for me it would just output a stereo source to the front 2 channels. I'd let my receiver do the decoding. As long as you can handle a DD standard signal should work out without mixing it.

This is Dolby Digital only, does nothing for DTS, DTS extended formats like EX and HD have the DTS core built in so you don't need to transcode it.