The GR-290 is running 1.6D , mixerctl -a gives:
outputs.master=255,255
outputs.master.mute=off
outputs.mono=255
outputs.mono.mute=on
outputs.mono.source=mixerout
outputs.headphones=255,255
outputs.headphones.mute=off
outputs.tone=255,255
inputs.speaker=127
inputs.speaker.mute=off
inputs.phone=191
inputs.phone.mute=on
inputs.mic=191
inputs.mic.mute=on
inputs.mic.preamp=off
inputs.mic.source=mic0
inputs.line=191,191
inputs.line.mute=on
inputs.cd=191,191
inputs.cd.mute=off
inputs.video=191,191
inputs.video.mute=on
inputs.aux=191,191
inputs.aux.mute=on
inputs.dac=191,191
inputs.dac.mute=off
record.source=mic
record.volume=255,255
record.volume.mute=off
record.mic=0
record.mic.mute=off
outputs.loudness=off
outputs.spatial=off
outputs.spatial.center=0
outputs.spatial.depth=0
Thanks in advance for any ideas.
-Mel