You are right that the official soundcard should be better documented. Here is what I remember, i.e. it may be flawed:
- ADC Left - Level adjustment of the left input
- ADC Right - Level adjustment of the right input
- ADC Left Input - Configure left input connector:
- No Select - Disconnect input
- VINL1[SE] - Tip & sleeve single ended/unbalanced
- VINL2[SE] - Ring & sleeve single ended/unbalanced
- VINL2[SE] + VINL1[SE] - Tip, ring & sleeve single ended/unbalanced
- [VIN1P, VIN1M][DIFF] - TRS differential/balanced
- ADC Right Input - Configure left input connector:
- Same options as ADC Left Input
- Digital Left - Level adjustment of left output
- Digital Right - Level adjustment of right output
- PGA Gain Left - Gain adjustment of left input
- PGA Gain Right - Gain adjustment of right input
Note that the gain adjustment allows coarse control of the overal gain of an input, allowing configuration for line, mic, etc. The level adjustment is an overal 0…100% level.
The input connector configuration can be useful for a few variations:
- Balanced signals on TSR - [VIN1P, VIN1M][DIFF]
- Unbalanced mono on TS - VINL1[SE]
- Two unbalanced (e.g. stereo) on TSR mixed to mono - VINL2[SE] + VINL1[SE]
VINL2[SE] is unlikely to be useful for most people but maybe you have a stereo signal on TSR and want to pick up the right channel only.
There are many other settings that are disabled by default and can be enabled in webconf but they are probably unrequired and it seems too much effort for me to document all of those|
[Edit] I have added this description to the V4 user guide. It could also be added to V5 but I didn’t want to touch that as I don’t know how we are porting the common (V4/V5) docs across. Anyone feel free to validate this description and update.