Hi,
I recently bought a Creative Soundblaster USB sound adapter,
for recording on my laptop (the inbuilt sound card doesn't bring the
line inputs out to a connector, so it's useless for recording).
Alsa recognises the device, but alsamixer shows several channels that
only half make sense to me.
There are two pairs of RCA connectors labelled line in and line out;
and a headphone jack with a volume control. Plugging anythinginto the
headphone jack seems to mute the line output.
Muting either `speaker' control from alsamixer also appears to mute
the line output. Also it's as if the speaker volume controls are in
series for line-in. But for PCM output, speaker 1 affects output
levels, but not speaker 0.
When a signal is going into `line in' it appears always to be echoed
to `line out' regardless of any settings other than the speaker
levels.
Can anyone (perhaps who has used this device under Windows) explain
the controls to me?
Simple mixer control 'PCM',0
Capabilities: cvolume cswitch cswitch-joined
Capture channels: Front Left - Front Right
Limits: Capture 0 - 128
Front Left: Capture 24 [19%] [off]
Front Right: Capture 24 [19%] [off]
Simple mixer control 'PCM Capture Source',0
Capabilities:
Mono:
Simple mixer control 'PCM',1
Capabilities: cswitch cswitch-joined
Capture channels: Mono
Mono: Capture [off]
Simple mixer control 'Mic',0
Capabilities: pvolume pvolume-joined cvolume pswitch pswitch-joined
cswitch cswitch-joined
Playback channels: Mono
Capture channels: Mono
Limits: Playback 0 - 255 Capture 0 - 128
Mono: Playback 0 [0%] [off] Capture 0 [0%] [on]
Simple mixer control 'Auto Gain Control',0
Capabilities: pswitch pswitch-joined
Playback channels: Mono
Mono: Playback [off]
Simple mixer control 'Speaker',0
Capabilities: pvolume pswitch pswitch-joined
Playback channels: Front Left - Front Right
Limits: Playback 0 - 255
Front Left: Playback 196 [77%] [on]
Front Right: Playback 196 [77%] [on]
Simple mixer control 'Speaker',1
Capabilities: pvolume pswitch pswitch-joined
Playback channels: Front Left - Front Right
Limits: Playback 0 - 255
Front Left: Playback 190 [75%] [on]
Front Right: Playback 190 [75%] [on]
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