Tiido wrote on 2020-04-24, 09:07:
Monster MIDI board is indeed very loud and the line in can only take up to 5Vpp (and some boards like DB60XG have 8Vpp output that clips any existing sound card out there). 0db point on input mixer is at the very bottom and on playback mixer at first notch on most inputs as seen here :
OptimalMixer.png
Driver side crashing is most peculiar though...
First, I would like rectify that changing Line-in Playback volume mixer does not change recording level . How I came to that conclusion, I do not know ( must have been really tired) .
I have also installed Audacity (Sound Recorder wasn't cutting it) so I can visualize the clipping directly while recording .
When I try the settings you suggested, I hear almost nothing of the daugtherboard playback through line-out, but recording line-in still clips (playback volume control does not control recording volume, which is normal), so it would seem the Audiotrix 3D/XG is not quit like other OPL3-SA cards .
Also strange is that this card was designed (or at least meant ) for the DB60XG which, as you say, is also very loud, so how do they prevent from clipping with that daughterboard ? If I understand correctly the OPL3-SA output is routed through the daughterboard so effects can be applied to PCM and FM synth and the audio of daughterboard is routed to Line-in of the OPL3-SA but also to Line-out and speaker out of Audiotrix card, which would mean the output of the DB60XG would have to be split, which would provide attenuation (3.5db ?) and this is would be how clipping is avoided with DB60XG .
Other daughterboards such as Monster MIDI do not have have line input, so the routing has to be different (changed with jumpers on Audiotrix 3D/XG card) and all the output power of the daughterboard is sent into line-in of OPL3-SA, which clips .
Also correct me if I am wrong, but I would guess that the line-input gain control in the recording mixer is digital gain after the ADC of the OPL3-SA, otherwise either there would have to be a separate signal path in the analogue mixer for line-in playback and for line-in recording, or line-in record level would affect playback volume, which is not the case .
EDIT : corrected a typing mistakes