(I' m a bit miffed with the site: I've just drafted quite a long and careful reply to the thread, and when I clicked to load it, I got an error message that 'my form is no longer valid', and the whole thing is lost. I wasn't that long !)

To say it all again, maybe a bit more quickly:

I've worked through ewverything Rachael and Ron suggested (thanks !) except maybe what Ron meant by the overrides (no reference to Thru in opt.pref.overrides ?)
I've worked a second time, carefully, through the various possible variations in Midi Drivers/Midi Options and Channels. I've set to 'boost Thru velocity' right up. Through out it all the situation remains stubbonrly that when Biab is at rest I can vary the Thru patch, play live on my input keyboard, and hear it from the synth; when I set the Biab song rolling, I can hear everything else from the synth, but not Thru.
I don't use Asio, and everything is 'hard' so latency is not an issue.

Also, 'Thru' works perfectly in two other applications, from the same setup , both for recording and playalong, without needing specific adjustment.

It must be something very simple. But what ?

Ian G.

Late-developing enthusiast for jazz / blues. Principally pianist