External Instrument delay problem

Cubase
1

Hi,
I’ve added some external midi instruments to my set-up - all working fine and playing back in sync with each other.

The problem?

  1. If I add a VST instrument to the arrangement - eg Groove Agent, it plays out of sync with the midi instruments. It plays about an 8th note late out of sync - which at 130BPM is 231ms.

  2. If I hit render in place on a midi part - eg drums of Roland TR-8 the audio file renders out but is delayed/late by approx quarter note.

  3. If I turn on Constrain Delay Compensation - eveything plays in sync.

  4. Neither external instruments or the VSTi have any insert or send effects on them and are showing zero channel latency when I view in the Cubase mixer.

Any thoughts on what I’m doing wrong - I’m assuming that I should be able to get external and VSTi to play in sync with each other?

Thanks in advance

2

So why do you turn it off? Does the button lit orange?

3

Sorry…I meant when I click the button and it turns orange, everything plays in sync.

But I want to work as I normally do so fully using VST FX and instruments as I build the mix without having to hit the DLC button to get things in sync?

4

I think what is confusing me is:

  1. External instruments have a delay when I hit render in place and examine the audio file. This is regardless of any use of CDC.

  2. The external instruments are out of sync with VSTs - but when I activate Constrain Delay Compensation everything syncs up.

I feel like the two points above must be related - but I can’t work out what I need to do to resolve so that:

  1. Render in place of external instruments is accurate - no delay

2.Live playback of External instruments together with VSTi is in sync

5

So to simplify things even further:

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Track 1 is midi going out through channel 10 to Roland TR-8
Track 2 is recording the audio coming back from the midi with monitor button engaged - the audio is in sync
Track 3 is then adding a new instance of Groove agent playing an identical beat.

If I now re-enable monitor on track 2 after adding the Groove agent plug-in - then the audio coming into track 2 is now out of sync by an 1/8th note.

So it is the action of adding Groove agent that is pushing the audio input to go out of sync?

If I now enable CDC then everything goes back into sync again.

image

6

On the same mini test project - if I add another External instrument - Roland V-synth playing a drum part.

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If I play the part on the Instrument track (track 3) it is out of sync.
If I play it on the midi part (track 2) which just goes out via the correct midi channel it is in sync with the original Roland TR-8 beat on track 1

7

OK - gave up on test project went back to main mix.
Tried Render in place of the external instrument - track at top of screen shot = out of sync.

But also tried just recording the input straight into cubase - the green track at the bottom =in sync.

So there is definitely a difference in render in place vs record audio when it comes to introducing delays with external instrument track types?

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8

Can anyone give me any pointers? Pulling my hair out here :frowning:

9

OK - worked it out - like most things it’s a learning curve.

I had set up one catchall external instrument called MIXER that was routing the combined audio of the TR-8 and TB-3 back through a mixer into the same pair of ins on my Focusrite.

Instead, this morning I tried creating two separate external instruments one for each synth, different midi channels but both coming in through the same audio inputs…and bingo - eveything in sync.

So - the learning here is that multiple external instruments can share the same audio input - my mistake was assuming that they couldn’t.

Problem solved.