VCV Host: Tempo Fluctuation

My first post!

When clocking a VCV Host instance using an input (coming from Impromptu Clocked in this instance, but applies to any clock module) and the various clocking options, the tempo of the contained plugin rapidly fluctuates by +/- ~1BPM

For sequencing or tempo-dependent VSTs this often causes instability. Some examples I’ve tried below:

FL Studio - attempts to resync running patterns approx one every 6-7 seconds - this momentarily brings the whole VCV patch to a halt (possibly due to high CPU usage while the VST is adjusting)

FXPansion Tremor - as above

Cherry Voltage Modular - Sync coming into the VM patch from Host drifts by a sixteenth-note every 10 seconds or so

A screenshot from Loomer Architect:

I’m aware of the following Issue - https://github.com/VCVRack/Rack/issues/1150 - but this was closed by Dev. I was unsure how best to follow up on that closed issue, so thought I’d throw it out to Community for points of view.

My thoughts:

Either VCV Host should improve clock processing to provide a stable, unchanging tempo to contained plugins

or

We should have an alternative method to provide tempo to the plugins, such as directly setting a tempo in VCV Host, or being able to provide a CV-based tempo (e.g. V/BPS) to its inputs.

My preference would probably be for the latter - as possibly even very infrequent changes to tempo for VSTs have the potential to make them “glitch”, and that might be unavoidable when reading clock triggers.

1 Like

Can you show a screenshot of Clocked?

Thanks for the bug report! I’ve reproduced it using Loomer Architect and I’ll investigate the cause.

3 Likes

Host 1.0.4 includes a fix - all the behaviours reported above have been eliminated!

Many thanks to all concerned :smiling_face_with_three_hearts:

3 Likes

A post was split to a new topic: Vcv Host : Opening Carla / FX/ Patchbay

That’s great - thanks for confirming that the fix is working for you.

1 Like

@Richie Should the clock be still stable in 1.2.2?
I’m exploring my Maschine VST and hardware again and it runs quite wonky in VCV Host (clock from CLKD at 24ppqm) but smoothly in Reaper.

image

It shouldn’t be doing that, or at least not to that degree… I don’t have the Maschine VST but I do have Loomer Architect, which shows a bit of clock jitter but only a fraction of a BPM, nowhere near as much as you’re seeing.

It actually works more smoothly at slower clock divisions, so if you were to give it a quarter-note clock, you’d probably see the jitter reduced to negligible levels - I see jitter of no more than a fiftieth of a BPM using Architect with a quarter-note clock.

That’s what they call the the inclusion of “human feel.” You don’t want to be a robot, now, do you? :slight_smile: