4-Mic Linear Array Kit Install Issue

I restarted with a fresh installation of the 2018-08-06-raspbian-for-respeaker.zip image, while the 4 mic round pi hat does immediately appear in the Preferences/ Audio Device Settings/ as: seeed-4mic-voicecard (Alsa mixer)



The 4 mic linear boards do not appear as an Alsa device.



Is there any additional setup steps needed for the linear board?



Have any basic debugging hints?



(I am Not using the board for an Alexa device, only using some audio processing functions)





FYI Here are the 2 Respeaker related directories I could find in the Seeed provided system:





/home/pi/respeaker/

2mic

4mic_linear

4mic

6mic

ns_kws_alexa.py

ns_vs_raw.py

ns_kws.py

README.md



/home/pi/respeaker/4mic_linear/

aec_ns_kws_alexa.py

aec_ns_kws_doa.py

oa_respeaker_

4mic_linear_array.py

aec_ns_kws_doa_alexa.py

aec_ns_kws.py

kws_doa.py



(all files 08/06/16)





/etc/voicecard/

ac108_6mic.state

asound_2mic.conf asound_6mic.conf

wm8960_asound.state

ac108_asound.state

asound_4mic.conf

dkms.conf