Ableton -> Mio10 -> OT -> Apollo 8
At least the tempo change moves nice to the Bassdrum
Yeah, gear that’s synced to midi clock can show fluctuations on the display.
A lot of devices do this.
If it’s just the display, no problem.
If the tempo actually changes, that needed to be investigated.
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On each beat, the tempo is calculated by the OT to set the display. The combination of jitter and rounding errors make it jump around a bit. Some synths use averaging over several beats so the display doesn’t jump that much, some don’t, or use a smaller window.
Best way to check if there’s a real issue is to record the click from the externally synced OT on a track in your DAW, and evaluate the jitter (are the recorded beats aligned with the DAW"s grid, are they fluctuating?). You’ll find some misalignment and some jitter which is normal especially with Ableton that reputedly has a not-so-stable clock. If it sounds fine to you ears, then there’s not much to worry about. If you’re making an occasional punch-in/punch-out overdub of your synced hardware in your DAW, you might need to manually align those. EDIT: good practice is to record a preroll of a bar in case you need to recover the lost attack of a kick or whatever.
However, once you have worked with a system synced to a really stable, sample-accurate clock (like the ERM multiclock or similar) you’ll find it hard to go back to software generated clock. This is especially obvious when you use several different sequencers for beats/percussion in parallel or do many overdubs of synced hardware in your DAW in which case a multiclock almost mandatory because all the manual adjustments to re-align the takes will disrupt your workflow way too much.
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Yeah, that’s jsut a reflection of how bad MIDI timing is, even with hardware that has good timing. I’ve seen a USB interface fluctuate by more than 10x that amount so it could be worse.
The frustrating thing is that it’s more than enough to mess up any seamless loops you’re using in the OT, and completely break pickup machines. I’ve never successfully slaved the OT to any other piece of hardware without at minimum occasional pops and clicks when live sampling, it just doesn’t handle the slightest clock jitter gracefully at all.
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Midi clock is 24ppqn so the best you can get, at 120BPM, is +/- 21ms accuracy which is sloppy. If a general purpose computer is master clock, it’ll probably be much worse than that, depending on what protocol is used to convert to midi. I stripe my DAW with SMPTE and use a SMPTE-to-midi synchronizer and get pretty much jitter-free sync, I guess ERM multiclock could do even better but that would be a marginal improvement over what I get now. Of course the hardware on the receiving end adds its own tolerance to the equation, but in my experience the hardware devices do not introduce extra variable offset to incoming midi clock, they might however add a fixed offset (my SP16 does so) which is why a ERM multiclock with it’s variable offset per output is still on my wishlist despite the price. (At half the price it would be a no-brainer)
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What are you using for SMPTE to MIDI conversion?
I stopped relying on midi sync from/to my daw already years ago. OT sends clock to AK, Shruthi and Bass Bot v2 via Mio4, which works pretty good.
I’ll just set my daw to the same tempo (part names in OT contain the tempo), use metronom with 2 bars count in and then just trim recordings.
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A Yamaha MSS-1 (vintage gear but saved me the 580€ for a ERM multiclock). Works great (but takes up some real estate on my desk).
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MIDI clock jitter tends to be more like .5ms (so +/1 .25ms) for hardware with really good timing (Octatrack, Atari ST, late 90s Akai hardware) and more in the 5ms to 10ms range for USB interfaces (the operating system makes a big difference here, with Windows 7 being notoriously bad, Windows XP and most versions of MAcOS being passable, and some reports of people being able to get some USB interfaces with more recent versions of MacOS close to good hardware timing), but anything above 2ms is starting to get a bit sloppy for really tight rhythmic sequences (for loose playing or slow pads or something you probably wouldn’t even notice 10ms).
It’s not the resolution of the clock that determines how tight the timing is, it’s the amount of jitter. Even a clock signal with 4ppq resolution is going to be extremely tight if the timing between pulses is really consistent. It determines the theoretical MAXIMUM amount of jitter, but anything that came anywhere near that limit would be unusable.
I’ve measured the jitter from my old MOTU Express XT interface on a Windows 7 machine (Notorious for having some of the worst USB MIDI timing of any operating system) and it was around +/- 3.5ms, which was more than enough that if I tried to record layers of synced notes (recording multiple passes with the internal arpeggiator in a synth with the DAW as the master clock was where it was especially noticeable) was essentially impossible because the jitter was so high you would hear audible flamming.
These days if I’m using the Octatrack I manually set the tempo and set it to respond to star/stop commands but not clock, so it will start in time with the DAW transport but will run on its internal clock and act as the master clock for anything else I’m using. That works really well, the OT’s internal clock is stable enough that I’ve recorded 90-120 minute live jams once or twice a week for the last four months and they’ve stayed in time with the DAW’s grid perfectly from beginning to end without any external clock.
If I absolutely need to send clock from the DAW I’ve got an Expert Sleepers USAMO but even that isn’t stable enough for the Octatrack (it’s more than stable enough that it sounds perfectly tight, but it still drifts enough to break pickup machines if I try to sync the OT to it - I have a feeling that’s more on the OT than the Usamo, though, because the same thing will happen with any hardware clock source I’ve tried).
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thx everybody for all the valuable feedback here!
I managed to solve the jitter and also the recording delay problem:
1.) get the clock signal for the OT from one of my Overbridge connected Elektron devices via Ableton - no jumping around anymore
AND for the recording
2.1) Route the audio from Apollo to an External Instrument in Ableton with adjusted Hardware Latency Compensation (Good starting point is to route the audio from OT to an audio channel, record some bars and then measure the delay in the audio clip)
OR
2.2) Route the audio out of the OT to the In of an Overbridge connected Elektron device
Cheers
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That’s an interesting point. I’ll try this out. If an Overbridge connected device could be a reliable clock source for my whole system with the DAW remaining the master, that would be awesome, because I would then be able to do tempo ramping much easier than the way I do this right now. That would basically be single channel alternative for the multiclock. I’ll use the Digitone for this, I always found it’s clock nice and tight.