The SAMSON CO1U microphone uses a stereo chip where the left channel should be the final output. However, on linux, we see the post-proc(left) and raw(right) signals separately. To fix this, we can map the left channel to both channels reducing to a proper mono channel. (Compare to setting a mono signal on pavucontrol
which gives a screwed up noisy signal).
Add the following line to /etc/pulse/default.pa
(or whichever file is being used -- see http://manpages.ubuntu.com/manpages/bionic/man5/default.pa.5.html )
# SAMSON CO1U HACK
.nofail
load-module module-remap-source source_name=samson-co1u-hack master=alsa_input.usb-Samson_Technologies_Samson_C01U-00.analog-stereo master_channel_map=left,left channel_map=left,right remix=false
.fail