Polybrute only syncs when record enabled

[robotstars78]

Hey all! I'm hoping the hive mind can help me a little.

I'm running Cubase Pro 11. I love it. I've always loved Cubase.

My issue is confusing the hell out of me though!

I've recently bought myself a shiny Arturia PolyBrute, and it all works well (after some teething trouble getting it to sync with the actual synth and talk to it properly), except in the sync department. That bit is causing me no end of trouble.

I'm currently at the stage where the synth will sync and stay in sync, but ONLY if I have the PolyBrute Connect VST track record enabled (the little record button on the track itself has to be switched on). If it's switched off the synth runs ahead of the project time. Which isn't great when I want to be jumping around to different tracks to record data. Currently I've had to disable the auto-record enable setting in Cubase preferences. A feature I'd really like to keep on! I've also noticed that if I have monitor enabled on the VST track, it also pulls it back into sync (how weird!)

I guess I should say it IS in sync, I can change the project tempo in Cubase and any synced LFOs or effects on the PolyBrute also change correctly. It's more the time offset - the PolyBrute playing ahead of the Cubase project - that's the issue. I have "constrain delay compensation" turned off (although turning it on makes no difference).

I've uploaded a quick video to show you what I mean - https://vimeo.com/674404808

In Cubase Projoect Synchronisation set up I have Midi clock set as a destination to the PolyBrute. I've linked pictures on this message so you can see it.

Edit: I realise I can add a time offset to the track (around 100ms seems to work ok), it's just a faff when I then need to remove it when I'm directly editing that specific track.

Interestingly, if I don't have record enable selected and let the track just play ahead of the project slightly, it's also not particularly well synced with itself. it sounds like the notes are slightly out of quantize with each other - only very slightly, but it's definitely not a perfect tempo. Click record enable and boom, all back in sync and playing beautifully!

Also, it doesn't matter what I set my ASIO latency set to. I can have it right down at 8ms or all the way up at 2048 and it makes no difference

Any ideas??!

[larioso]

There is one bug acknowledged where PB sends it's own start/stop of sequencer when on external clock which created problem when started from daw sequencer suddenly become like slave to PB with timing issues.

Not all sure this is your problem, but good to know I think.
When PB getting start/stop on input it should not send it's own like you pushed play on PB as well.

To possibly create a workaround, did you try record the sequencer itself?
Having the midi you can quantize it in Cubase.
If setting to send sequencer/arp midi is on, you can record that. Usually on midi channel 2, same as sequencer.

Or at least knowing about this start/stop issue you can think of a better way to work around it until fixed in next fw update.

[robotstars78]

Thanks for the advice Larioso.

I actually just solved the issue!

Posting this in case it helps others. I found out that it was ASIO Guard causing the issues. Whenever I don't have the track selected (ie with record enable on), ASIO Guard jumps in to protect the latency of everything by adding in delay latency... Which is of course absolutely fine, EXCEPT when you're playing an external instrument into it which of course circumnavigates ASIO guard. Hence why it was playing BEFORE everything else in the track. I've disabled ASIO guard and all is working well. Of course it adds to the workload of your machine, but hopefully it'll all be ok now!

[larioso]

Good catch and thanks for feedback.

As I recall there are settings which instruments are part of ASIO GUARD or not.
If your machine crumbles, I mean.

From manual
Restrictions
The ASIO-Guard cannot be used for:
● Realtime-dependent signals
● External effects and instruments

If you select Studio > VST Plug-in Manager and click Show VST Plug-in Information, you can
deactivate the ASIO-Guard option for selected plug-ins.

[robotstars78]

Oh you little beauty... I had NO idea I could do that!

I did actually make it work for me without having to turn ASIO guard off at all. I'd got it set to high priority/boost, all of that jazz. I changed it to the settings in the picture below and it all works nicely now. However, I think your method for simply turning off ASIO guard for the Polybrute VST and leaving everything else as it was is much more elegant.