The "future post"
With Martin's help (and Thái from Thorvin) I've been trying to set up the new lab machine's sound cards, now with some urgency after Eric G's report.
In Lab B it appeared as though I would need to make jumper adjustments on the audio network hub on each student station, but repeating the setup in Lab C I achieved similar results without changing the jumper...(?)
I have an email in to Thái right now regarding some remaining questions and will update this post when I know more.
The remaining issues revolve around the Sanako Duo recording streamed transfers. One concern is that it records to both channels during a stream from the teachers station (as in cassette, teacher-as-source and cd audio being transferred directly). Watching the transfer in "graph" mode on the SW I see that it goes to both student and program channels. If the student plays it back immediately after re-gaining control of the player they get a "echo-ey" effect - like pseudo stereo - that interferes with their ability to record their own voice.
Another issue is that each of the "transfer" streams ends up at the SW with a different recording level. Cassettes sound OK, but teacher-as-source is way too loud and CD audio is rather quiet. The recording level on the student microphone is also boosted when these transfers take place - almost as if there is some instruction coming from the TS that overrides the SW settings.