Hey man, I just got another OP-1 after around a year of not having one, so I haven’t had enough time to successfully recreate this on the OP-1 specifically. So take my advice with a grain of salt, but I use a very similar method to this on my SP404 and SP555. And for me its all in the levels when your sidechaining thru a single source.
As far as the levels go on my beats:
I will have the kick playing the loudest, on my SP404 I put it at max volume (so like 99 on the OP-1) The kick has to be significantly louder then the other elements of the track to make the entire track duck out. Also having a kick with good sub bass if really important as well. Something about those lower frequencies really helps get the song to pump.
Then I will have the snare the second loudest, Loud enough to where its punching through but a little bit quieter then the kick.
Third is the main sample/melody, which will be significantly lower then the kick and snare, BUT once all of your elements are laid down feel free to solo the sample/melody and kick and play with the sample volume to find the right volume setting for maximum Ducking. Too loud or too quiet and it wont duck when the kick hits.
Fourth is hi hats/percs, This is more so just my preference but I usually will have the hi hats a little quieter then the main sample/melody but loud enough to where their still good in the mix,
Lastly for me is bass, I usually have the bass around the hi hats/Sample’s loudness, but once again this is mostly just preference.
On my SP the volume range goes from 0 (quietest) to 127 (Loudest) Here are the estimated levels I set for my tracks
Kick (115-127)
Snare (75-90)
Hi hats (40-65)
Sample/Melody (40-65)
Bass (40-65)
I hope this helps you out a little man, peace 