No sound at all - onboard ASRock K7S8X motherboard

I’ve also found this Alsamixer - ALSA wiki but that only gives me the option of changing the master volume level

Are you certain?

According to the script you ran, the following controls are available on your PC:

!!Amixer output
!!-------------

!!-------Mixer controls for card 0 [SI7012]

Card hw:0 'SI7012'/'SiS SI7012 with CMI9761B at irq 18'
  Mixer name	: 'C-Media Electronics CMI9761B'
  Components	: 'AC97a:434d4982'
  Controls      : 40
  Simple ctrls  : 27
Simple mixer control 'Master',0
  Capabilities: pvolume pswitch pswitch-joined
  Playback channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Mono:
  Front Left: Playback 31 [100%] [0.00dB] [on]
  Front Right: Playback 31 [100%] [0.00dB] [on]
Simple mixer control 'PCM',0
  Capabilities: pvolume pswitch pswitch-joined
  Playback channels: Front Left - Front Right
  Limits: Playback 0 - 255
  Mono:
  Front Left: Playback 255 [100%] [0.00dB] [on]
  Front Right: Playback 255 [100%] [0.00dB] [on]
Simple mixer control 'Surround',0
  Capabilities: pswitch
  Playback channels: Front Left - Front Right
  Mono:
  Front Left: Playback [off]
  Front Right: Playback [off]
Simple mixer control 'Surround Jack Mode',0
  Capabilities: enum
  Items: 'Shared' 'Independent'
  Item0: 'Shared'
Simple mixer control 'Center',0
  Capabilities: pvolume pvolume-joined pswitch pswitch-joined
  Playback channels: Mono
  Limits: Playback 0 - 31
  Mono: Playback 31 [100%] [0.00dB] [off]
Simple mixer control 'LFE',0
  Capabilities: pvolume pvolume-joined pswitch pswitch-joined
  Playback channels: Mono
  Limits: Playback 0 - 31
  Mono: Playback 7 [23%] -36.00dB] [on]
Simple mixer control 'Line',0
  Capabilities: pvolume pswitch pswitch-joined cswitch cswitch-exclusive
  Capture exclusive group: 0
  Playback channels: Front Left - Front Right
  Capture channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Front Left: Playback 24 [77%] [1.50dB] [on] Capture [off]
  Front Right: Playback 24 [77%] [1.50dB] [on] Capture [off]
Simple mixer control 'CD',0
  Capabilities: pvolume pswitch pswitch-joined cswitch cswitch-exclusive
  Capture exclusive group: 0
  Playback channels: Front Left - Front Right
  Capture channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Front Left: Playback 21 [68%] -3.00dB] [on] Capture [off]
  Front Right: Playback 21 [68%] -3.00dB] [on] Capture [off]
Simple mixer control 'Mic',0
  Capabilities: pvolume pswitch pswitch-joined cswitch cswitch-exclusive
  Capture exclusive group: 0
  Playback channels: Front Left - Front Right
  Capture channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Front Left: Playback 0 [0%] -34.50dB] [off] Capture [on]
  Front Right: Playback 0 [0%] -34.50dB] [off] Capture [on]
Simple mixer control 'Mic Boost ( 20dB)',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [off]
Simple mixer control 'Mic Select',0
  Capabilities: enum
  Items: 'Mic1' 'Mic2'
  Item0: 'Mic1'
Simple mixer control 'Video',0
  Capabilities: pvolume pswitch pswitch-joined cswitch cswitch-exclusive
  Capture exclusive group: 0
  Playback channels: Front Left - Front Right
  Capture channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Front Left: Playback 24 [77%] [1.50dB] [on] Capture [off]
  Front Right: Playback 24 [77%] [1.50dB] [on] Capture [off]
Simple mixer control 'Phone',0
  Capabilities: cswitch cswitch-exclusive
  Capture exclusive group: 0
  Capture channels: Front Left - Front Right
  Front Left: Capture [off]
  Front Right: Capture [off]
Simple mixer control 'IEC958',0
  Capabilities: pswitch pswitch-joined cswitch cswitch-joined
  Playback channels: Mono
  Capture channels: Mono
  Mono: Playback [on] Capture [off]
Simple mixer control 'IEC958 Capture Monitor',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [off]
Simple mixer control 'IEC958 Capture Valid',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [off]
Simple mixer control 'IEC958 Playback AC97-SPSA',0
  Capabilities: volume volume-joined
  Playback channels: Mono
  Capture channels: Mono
  Limits: 0 - 3
  Mono: 0 [0%]
Simple mixer control 'IEC958 Playback Source',0
  Capabilities: enum
  Items: 'AC-Link' 'ADC' 'SPDIF-In'
  Item0: 'AC-Link'
Simple mixer control 'PC Speaker',0
  Capabilities: pvolume pvolume-joined pswitch pswitch-joined
  Playback channels: Mono
  Limits: Playback 0 - 15
  Mono: Playback 0 [0%] -45.00dB] [off]
Simple mixer control 'Aux',0
  Capabilities: pvolume pswitch pswitch-joined cswitch cswitch-exclusive
  Capture exclusive group: 0
  Playback channels: Front Left - Front Right
  Capture channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Front Left: Playback 0 [0%] -34.50dB] [off] Capture [off]
  Front Right: Playback 0 [0%] -34.50dB] [off] Capture [off]
Simple mixer control 'Mono Output Select',0
  Capabilities: enum
  Items: 'Mix' 'Mic'
  Item0: 'Mix'
Simple mixer control 'Capture',0
  Capabilities: cvolume cswitch cswitch-joined
  Capture channels: Front Left - Front Right
  Limits: Capture 0 - 15
  Front Left: Capture 0 [0%] [0.00dB] [on]
  Front Right: Capture 0 [0%] [0.00dB] [on]
Simple mixer control 'Mix',0
  Capabilities: cswitch cswitch-exclusive
  Capture exclusive group: 0
  Capture channels: Front Left - Front Right
  Front Left: Capture [off]
  Front Right: Capture [off]
Simple mixer control 'Mix Mono',0
  Capabilities: cswitch cswitch-exclusive
  Capture exclusive group: 0
  Capture channels: Front Left - Front Right
  Front Left: Capture [off]
  Front Right: Capture [off]
Simple mixer control 'Channel Mode',0
  Capabilities: enum
  Items: '2ch' '4ch' '6ch'
  Item0: '2ch'
Simple mixer control 'DAC Clock Source',0
  Capabilities: enum
  Items: 'AC-Link' 'SPDIF-In' 'Both'
  Item0: 'AC-Link'
Simple mixer control 'External Amplifier',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [on] 

You can get an update of that any time by typing “amixer”. Or to copy it to a text file just type: amixer > amixer.txt and open up “amixer.txt” with a text editor or word processing program.

positive, even running alsamixer in a terminal only gives me the one option

Well, I’m not a gnome user, so I can not help you there. But the script output clearly shows those mixer settings can be controlled.

You need to get a gnome user (and many on our forum rave how much they like gnome over KDE) to help you there. There is something amiss in your mixer, and its definitely desktop specific. And as a humble KDE user, I can not help.

ok, and thanks for all your help