MIDI latency is 'remembered' in Live set. Very odd behaviour...

[rev_engineer]

I am using a Push 2 and some MIDI-generating M4L devices to send MIDI from a Live track to an external Xoxbox 303 via an NI Komplete Audio 6 (using MIDI cable, not USB). I then send the 303 audio signal back to a Live audio channel via the NI's audio input. It's generally working fine.

I've just opened a finished set which used this setup but that has recorded 303 parts. I'm deleting the recoded audio loops and reinstating the MIDI so I can perform the tune live, but there's pretty severe MIDI latency. I started a new dummy set as a test and checked the basic setup as described above: no latency. I re-opened the finished set, deleted everything but the MIDI channel and the audio channel coming back from the 303: latency. I deleted literally everything in the finished set and made a new MIDI channel and a new audio channel from the 303: latency. I made another dummy set (no latency), copied the working MIDI and audio channels and pasted them into the finished set with everything else deleted: latency. I then tried it the other way around - I copied the MIDI and Audio tracks from the otherwise empty finished set (latency) and pasted them into a new set: no latency.

Seems that my finished track is somehow 'remembering' the latency even when literally everything else is deleted (so it's effectively a new set) and it's using fresh tracks to send MIDI and receive audio. This is really weird behaviour!

Any thoughts would be wonderful. Gig is in 2 days :-/

[rev_engineer]

Ferchrissake. It was a plugin lurking in a return channel - Soundtoys Little Alter Boy. Wasn't even turned on. Delete it: no latency. *sigh*