Hey friends. I posted this advice on the op1users subreddit and it was suggested I post it here too. When prepping for a show last week I made a discovery which might benefit many of you.
I’ve seen a few posts from folks like me who love to perform with the OP1 but sometimes want to finesse the loops they’ve sketched out in a DAW like Ableton before using them in a live performance. I’ve seen a few people say when they bounce their tape files and import them back onto the OP1 (as mono AIFF files named “track_1, track_2” etc) they find all of their audio appears on the tape timeline as one long clip, even when they made the file with gaps of silence between the clips.
A few have suggested that you just have to scrub through manually and cut your loop points, but it’s very hard to do that accurately on the OP1 interface. I noticed that when the OP1 starts up after new tape files are transferred it does do a process on each track called “scanning track clips”. I thought surely there must be some way to make the OP1 recognise that silence is not part of a clip.
After a bit of experimenting I had a hunch that the clips scan might be looking for when the sound level drops below the -96dBFS noise floor of a 16-bit audio file. Then I remembered that I usually have Ableton set to render with one of the POW-r dither settings.
Without getting too into the weeds on how dithering works, many DAWs have these POW-r dither settings which shape the noise floor so it sits at a higher level in the less audible higher frequencies, but lower in the more audible ranges. This is normally a great thing, but it does mean if (huge if) what the OP1 is scanning for is that magic -96dBFS silence, it’s never going to find it.
I tried rendering my tape files out again using the totally flat Rectangular + Triangle dither settings Ableton has and sure enough my clips showed up on the timeline perfectly! It was a total game changer for my show. I could quickly select the In/Out points of my loops on the fly using Shift < > and they played exactly how I made them in the DAW.
I did find when there was less than a few seconds of silence the clips weren’t recognised totally accurately so further experimentation might reveal what the minimum gap is. You’ve also gotta watch out for reverb tails or anything like that confusing where the exact end of your loop is. It’s gotta be true digital silence.
I’m excited that this also opens up possibilities for doing more fancy things in stereo. I do a lot of Mid/Side processing in my mixes which is impossible on the OP1, but I could bake such things into a Left and Right tape file, then hard pan two of the tracks on the OP1 and playback would be the same.
Hope that helps a few of you out!