Stability issues trying to sync Ableton via Expert Sleepers + 'CV Clock In'


I am trying to send a clock signal from VCV to Ableton via an ESX-8CV + ES-6 so that Ableton is the slave. For this purpose, I am using the ‘CV Clock In’ device from CV Tools.

However, I am getting a strangely unstable clock, whereby the tempo in Ableton will always oscillate between two closely related values e.g. 120.9 BPM and 121.4. BPM.

I have tried various clocking configurations, including unipolar square-wave LFOs, Impromptu Clocked etc. but am getting the same instabilities (well actually, the inconsistencies are more or less pronounced, depending on which VCV Clock source is used).

I was just wondering if anybody has had any experience with this, and if you had any advice? All I can think of is adjusting the pulse width, but this hasn’t had much affect.

I’m actually trying to do the same thing in Max/MSP with similarly unstable results. If anybody has any advice for getting better results out of either of these two programs, I would be greatly appreciative.

I am using a Windows 10 desktop computer with a Behringer UMC1820 audio interface, connected with an ES-3/ES-5/ES-6/ESX-8CV over ADAT. If there’s any other info that I can provide which might be useful, please let me know.


I’ve no experience with Expert Sleepers, but have synced Ableton and VCV Rack using the techniques Omri talks of in this video, basically sending a square wave

I have an Expert Sleepers ES-9 and had similar issues with externally clocking Live. I don’t think it’s a problem with Expert Sleepers but rather that Live is inherently unstable when externally clocked with clock pulses. I’ve had much better results doing things the opposite way: use Live as the master clock and VCV as the slave (but note that you’ll want to sync VCV using audio clock pulses sent from Live, not MIDI; for some reason external MIDI clock into VCV isn’t always stable).

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Thanks for your perspective on this. I sort of guessed the problem didn’t lie with ES, but I didn’t realise that about Ableton’s CV clocking issues; good to know.

I’m surprised it’s that bad though. Os has murmured on ModWiggler that Ableton should support his modules natively, and I absolutely agree with him. The guy clearly knows what he’s on about with this stuff.

Anyway, yes, I’ve seen that clocking the other way round wouldn’t be an issue, although I haven’t tried it myself, as I basically need it to be this way round.

I got decent results this morning by sending a clock to ‘Sync In’ on the Arturia Keystep, and then sending a MIDI Out to the Behringer UMC1820 audio interface.( I say “decent”, although it’s just the usual jittery MIDI clock. Better than before though.)

It’s mainly just for syncing effects in Ableton, so the clock doesn’t need to be as stable as it is for CV generation, so this might have to do for now.

If anybody has any suggestions for combating shitty Ableton CV sync, I’m all ears. I’ve had a quick look at the ‘CV Clock In’ device in Max, and it doesn’t look too complicated…maybe it’s worth throwing together a fresh device to see if it can iron out any creases.

I’m subscribed to Molten Music Technology on YT and he mentioned there’s a new module that permits a modular system to use Ableton Link, not ultra cheap though and obviously does nothing for VCV Rack, but it’s an interesting thought for someone to produce a VCV Rack module that can sync with Ableton Link. The module is…

That’s great to see hardware implementations of Ableton Link in a module like that.

Your reply prompted an idea to play around with a certain VCV competitor’s app on my iPad yesterday, as that is essentially a hardware Link module too (seemingly mentioning the competitor by name is enough to get your post on here removed).

So yes, there is already a very good Ableton Link modulae available from Stellare Modular:

Yes, had that pointed out in another thread. I would have found it but I had searched the library for the phrase “Ableton Link” so never spotted it.