the M-audio keystation 88ES is not a keyboard, it's a MIDI controller only. there is not an internal hardware synth onboard, so routing back thru the delta 1010 and using it's monitor mix will not work.

keebo - you need to have the TTS-1 installed as your DX output synth in the MIDI options in BIAB (I'm not at my BIAB computer right now to tell you exactly how to set that up, sorry).

the info about ASIO is correct - you'll need that for low latency from the keyboard thru BIAB/TTS-1 to get a playable solutino. otherwise you'll have high latency and won't be able to play because of the slow response. I agree with Andrew that the m-audio native ASIO drivers should work for you by selecting "always use ASIO" like he suggests. ASIO4ALL will work as well, but I think there shouldn't be any reason the native m-audio ASIO driver wouldn't work and it's perferable over the ASIO4ALL (which is actually a WDM wrapper).

if you don't have your MIDI output selection set correctly for the DX output for TTS-1 then that would be a reason you can't hear anything while playing your keystation thru BIAB. if you can't find those menu optinos I'll look at it when I get home and help you then.