I just resurrected my node with an Alinco DR-135 which I've been using for years with my node, its audio levels are fixed via the data port connections.
The node computer has been changed to an old HP T5000 thin client with the IRLP Debian 8 install (9 or later wont install due to 128MB ram limitation).
Card: VIA 8235
Chip: VIA Technologies VIA1612A
in alsamixer I cannot find a way to adjust the mic level, I can turn the 20dB boost on and off. With it off audio level too low, with it on its way too hot.
Tried every slider there is up down makes no different to the mic level.