Octratrack - Live looping sync issue

Elektron Gear Octatrack
1

Dear Friends,

I am currently facing an issue with perfect looping on the OT.

What I am trying to do :

  • Record 4 bars of syntakt and digitakt from inputs A-B and C-D and loop it on two flex machines (one per instrument)
  • Pattern 1 has a recorder trig (on grid, trig 1)
  • Pattern 2 has no recorder trig
  • Scene 1 mutes the track with the recorded buffer (flex track)
  • Scene 2 mutes the tracks with the live input (thru tracks)

The goal here is to use the fader from live to recorded track to bring in new voices smoothly.
Then I can switch to pattern 1, record the audio with the new voice, go back to pattern 2 and do it over again till all my voices are in the audio.

How I do it :

  • Recording setup is set as :
  1. INAB A B for ST INCD C D for DT
  2. RLEN : 64 (4 bars)
  3. TRIG : ONE
  4. LOOP OFF
  5. FIN 0.063
  6. FOUT 0.0.63
  7. QREC PLEN
  8. QPL OFF
  • Flex machine setup
  1. LOOP off
  2. SLIC off
  3. LEN off
  4. RATE PTCH
  5. TSTR OFF
  6. TSNS 64

Switching to pattern 1 triggers the recording for 64 steps length
Going back to pattern 2, I trigger my two flex machines with a trig on step 1.

The problem :

When the recorded buffer starts playing, it is not synced with the live audio.
Both kick are slightly off sync so it sounds awful.

Mitigation :
I tried setting the playing trigs of patt 2 -1/32 with the micro timing
This syncs the audio but creates an imperfect loop

I checked the recorded buffer on its own via audio editor and playing it, I hear a perfect loop (minus a click that I can fix with increased FOUT)

I’m pretty sure it’s something dumb that I am missing but I can’t seem to find info or someone else that ran into this issue.

Maybe I just need more coffee.
Thank you in advance for your help or suggestions

2

If you’re listening to the live audio through the OT with DIR I think you might need to enable a latency compensation setting in the settings. The OT has a little latency to it that you may need to account for, another possibility is setting a short delay in your audio interface if it has the capability, or you can do it in a DAW.

I think that’s what’s going on based on your description anyway, a latency thing.

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3

There’s a Delay compensate setting in the OT in case.

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4

IIRC there’s something about using FIN/FOUT that messes up the sync of the audio (settings other than zero add length to the audio file or something like that). I don’t remember exactly what the deal is, but it’s in the manual. Try your technique with FIN/FOUT both set to zero.

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5

This applies when using looping samples, and it’s the FOUT that needs to be set to 0 otherwise it will go out of sync with the sequencer. It’s a weird undocumented quirk IIRC, I only found it after troubleshooting and finding a post about it on this forum. I don’t think it’s the culprit in this instance however as the samples aren’t being looped but are trigged instead, so it’s probably just OT’s processing latency causing its sound to be delayed slightly vs the live sound.

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6

This is through the Main out.

My audio interface is a mixer without compensation for latency.
I use the OT for live performances.

7

found the setting in the manual, will put it at 1/32 and report

8

It’s only a true of false setting, this doesn’t allow me to sync properly the loop and the live audio, sadly

9

do you have any clue how to fix it ?

10

It’s not clear what your signal routing is exactly, it might help us if you draw a rough little diagram of the setup.

11

here you go

12

Would looping samples instead of triggered samples fix that ?

13

I don’t know if this could be related to a MIDI sync issue, others will be more knowledgeable about that.

I’m guessing you’re using the DIR setting in the OT’s mix menu to route the live input to the main outs? Does the issue persist if you use a thru track instead?

You shouldn’t need to loop samples no, doesn’t seem like that would help you in this instance.

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14

ST (T1) and DT (T2) are thru tracks (that I record and play with flex tracks T5 and T6)

T8 is my master track.

In my mixer menu, DIR is at 0 for both AB & CD

15

MIDI is originating from DT, Thru ST and to the OT

16

Ok, if my understanding of the OT is correct it might not be a processing latency thing if you’re using thru tracks, because listening to live input that way should invoke a bit of delay which should match stuff being played on flex tracks.

What is the time difference between the two kicks, and is the recorded sample ahead or behind? Maybe record a short sample that demonstrates the effect so we can get a better idea of what’s happening?

I’m not very experienced in MIDI sequencing stuff so hopefully others have better suggestions, because it might be something to do with how MIDI sync works.

17

Even weirder, I realized that, only the DT input exhibits this behavior.

Its kick is 1/32th (live) before the record plays, so I need to offset the T6 playing the recording buffer with microtiming of -1/32.

ST’s playing’s trig on T6 can be on the grid without desync from the output.

18

https://file.io/1rL7U0RP6lG1

Here is an audio file
Since the ST is sidechained, you can hear how awful it is when it is not in synch with the DT.
DT has the kick.

I started the recording with the playing trig for the DT recorded buffer offset by -1/32 (still can hear some phasing and the end of the loop being incorrect), then I removed the offset and made your ears bleed

19

Any microtiming trig set on?
Which device is sending the clock?

Did you set the settings of the F.IN / F.OUT to zero?

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20

microtiming set on the DT buffer play so it’s in sync, I checked for other microtiming trigs and didn’t see any

DT is sending the clock, thru ST and to OT

I gotta check the F.IN and F.OUT to zero, didn’t do that yet