Nonexistant IEC958 digital audio prevents analog audio working

This problem is with KDE in both Leap:15.6 and Tumbleweed

I’ve just installed a new H81 chipset motherboard. The previous one had a dud memory slot and also had a back panel spdif connector which I’ve never used.
With the previous MB when I plugged in the speaker jack it automatically switched to analog.
Now with the new MB which has no sign of digital audio on the outside when I plug the jack in it oscillates between digital audio and analog.
I’ve scoured the web for a way to banish digital audio also no settings in bios.
Does anyone know how I can remove digital audio for good

Use alsamixer.

You don’t need to remove it as such - just configure the sound with the preferred profile and output device. If you have ‘pipewire-pulseaudio’ installed, you can use ‘pavucontrol-qt’ to configure as required. If necessary, install it first (package of the same name).