Hi all!

Thanks for the input. I've checked the thru volume and all other obvious parameters i could think of. It doesn't make any difference. I've used MIDI and DAWs for some 30 years (since Notator on the Atari) but never encountered something like this.

I don't think the drivers are the problem. All other channels play fine. BIAB receives the midi note messages (visible in the big piano window e.g.). Also, the midi notes are sent out to the Yamaha 750 BUT are played at an incredibly low volume. At normal listening levels (for everything else) they are barely possible to hear provided everything else is quiet. I tried a couple of re-routings but to no avail. Using the Yamaha as input keyboard - same result. BUT, when i use Roland JV1080 as playback device the thru channel plays back perfectly! The JV1080 is, however, not a good general choice. This makes me guess that some midi message which is lowering the volume, but that the JV1080 cannot interpret, is sent out.

I don't know if there's an easy way to monitor the outgoing midistream from within BIAB.