how do I sync the time signature of Ableton with the patch?! Help!

So im using vcv to generate generative music within Ableton and use it for live looping. I was able to synchronize the general tempo to run the sequences and external VST instruments but I can’t seem to be able to synchronize the time signature. I want to be able to change time signatures live and have the sequences restart accordingly so they are neat and organized for the loopers. but I can seem to find a way. Within the CV-midi module the CLK/n option lets me have the different resolutions and then a basic clock divider that doesn’t align itself with Abletons time signature. any ideas? Thanks in advance!


MIDI-CV and CV-MIDI modules doesn’t have stable clocking/timings about their CLK and CLK/N ports (as outputs for MIDI-CV, as inputs for CV-MIDI).

Take a look about this post

For my new clocking module, it can’t sync correctly from external MIDI source (such my Arturia’s BeatStep Pro, as master clock source). The tempo fluctuates constantly around the real value. Noticed the same behavior by using Impromptu Modular CLOCKED module (set as 24 PPQN, like my BeatStep Pro and MIDI-CV module) as slave.

Concerning Ableton Live, maybe you’ll can consider Link module, or Link v2 module. I don’t have tested them because I don’t use Ableton Live.

I find having Rack being clock source syncs clock on my Keystep 37 and seems stable well, mostly, (at 24ppqn). Much less jitter than the other way around…

What OS are you using?

(This problem seems affect Windows platforms and USB).

I’ve tried 24 PPQN, but not stable, except at lowest tempo (near BPM 30, minimum value for BeatStep Pro).

The BSP is upto date: have lastest firmware, lastest Arturia MIDI driver, lastest MIDI Control Center application.

My OS is Windows 10 Pro x64 22H2.

don’t know if that can help, but having issues with soundcard stability in windows with USB, instead of having plugged directly in the USB port on the laptop i have plugged through an USB hub

no logic explications but it works for months now

I think you should have an automation lane in ableton to control a specific group of module in VCV,to control immediately the time signature in VCV

I’m not an expert but for sure I’ts possible

ERRATA: you want make that in live,I don’t view solutions

Are you talking about time signatures or tempo change? Because time signatures are 3/4 or 9/8 or whatever, and I don’t see how that is relative to a sequence in Rack. Unless you are using a trigger to reset the sequence at the beginning of every “bar”.


I’ve tested direct (motherboard) USB3.1, and via USB 3.1 HUB : same results.

Not a laptop, but a mid-case PC.

Me and auretvh are explaining you that you have to send a midi CC to change tempo signature

A midi clock don’t send signature

VCV sequencers just receive tempo from the DAW

Yeah, I don’t fully understand the question, but as you said, changing time signatures has got nothing to do with tempo, and can be done with a simple automation from the DAW. Changing tempo is an entirely different ball game. Especially if you are relying on jittery Midi clocks.


I think you should visualize the clock signal via an oscilloscope module in VCV,when you change the time signature in your DAW

MacOS 13.2.1, MacMini M1. I did see same on my old windows 10 PC (long mothballed) both from built-in USB 3.1/3.2 ports

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Ohmer[Dominique Camus] (Profile - Ohmer - VCV Community)

MIDI-CV and CV-MIDI modules doesn’t have stable clocking/timings about their CLK and CLK/N ports

Connect Clock out from MIDI-CV to Clocked BPM input & set Clocked BPM mode to P24.

Sync works tight for me. If you use the Host module with VSTs though all bets are off. As near as I can tell, Rack reports the sample delay accurately, but it doesn’t measure the additional delay for VSTs in Host modules.

It works for you, perfect but… what is your OS?

I’ve tried what you’re mentionning, but the sync issues occurs from both CLK and CLK/N (MIDI-CV), even by using P24 mode from CLOCKED (connected to BPM input).

The sync issues seems to concern Windows & USB only, not OSX, not Linux. Voila

What I remember is that the CLK/N – if you wanted to get a 16th note clock from the MIDI-CV for example – was wobbly, but that CLK worked OK.

So far it’s good for me, down to the zooming the waveform of recordings and seeing it line up with the bar lines perfectly. I don’t know what your setup is.

Are you talking about USB audio, or USB MIDI? What is the clock source? What is the clock slave?

I really have no trouble: Windows 11, Intel Core i7, Ableton Live Suite, Rack Pro.

If you’re trying to sync external midi, yeah sync from MIDI devices that should be solid wander all over the place.


What I remember is that the CLK/N – if you wanted to get a 16th note clock from the MIDI-CV for example – was wobbly, but that CLK worked OK.

Not for me, either CLK/N and CLK outputs, unfortunately.

From my MIDI controller (Arturia BeatStep Pro) and from DAW (Rack either as VST2, VST3, CLAP). About controller, I don’t have any trouble from other DAWs I’m using (Bitwig Studio 4, now 5 betas, REAPER 6.79, lastest Ableton Live 11 Lite). Only VCV Rack (v2.3.0 preview). As slave my new clocking module BPM isn’t stable, observed by scope, exactly same behavior concerning Impromptu Modular CLOCKED as slave (any mode was tested).

I’ve tried to connect the Arturia BeatStep Pro direct on motherboard (USB 2, USB 3) and USB hubs (USB 2, USB 3) but same results: constant jitters.

Thanks for your report here.

Yeah clock from external midi means windows is there to fuck things up. Bad clock jitter from external midi over usb is a feature built into Windows.

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It is exactly that. I wan to loop live and the loop starts at the beginning of abletions bar. and I want my vcv sequences to be synced with that so that live looping works

So if your tempos are synced as you say, and all you want to do is reset the sequencer at the beginning of a bar in Ableton.

You should be able to create a new midi track in Ableton, put in one note at the beginning of the bar, and send that notes gate to trigger the reset in the sequencer via VCV midi-gate.

Or, create an automation lane and automate the reset.

Sorry, I don’t use Ableton, but it should be similar in all DAWs.

Ignore this if I’m completely off.:smiley:

If you’re using session view and changing Live’s time signature by triggering scenes, easiest way to do this is to use clip envelopes on your VST track to align the changes. In order to set up the clock and divider, here’s my usual method:

  1. Set VCV MIDI->CV module to send 24 PPQN from Clock/N output
  2. Link to clock of Improptu CLKD, set to receive 24 PPQN
  3. Set up a clock divider - I’d recommend DocB’s CDiv - clocked by 8th notes from CLKD (or 16th notes if you’re really getting freaky), link that divider to retrigger your sequence
  4. In Live, set your VST to configure automation parameters, then select the clock divider parameter you’re using
  5. For each clip in Live you’re triggering, set a clip envelope to the respective scene’s time signature (using 8ths it’d be 8 for 4/4, 7 for 7/8, 6 for 6/8 or 3/4, etc)