Real-time loop start and length control

Hello dear Octatrack users,

I do not yet own an octatrack and want to know if an important tool I use often exists in Octatrack before I make my buying decision.

Is it possible to control a sample’s loop start and loop length parameters in real-time as the sample is playing. What I am after is:

either I play a sample by sending the OT a MIDI Note and then control the loop start & length by sending it MIDI CC.

or a sample is being played by the sequencer and I control the loop start & length either by sending MIDI CC or using on-board controls (knobs, crossfader).


Yes, you can assign these parameters to scenes and use the cross fader, or move the knobs.

100% yes, but you’ll need to use a Flex machine rather than a Static machine if you want the best results when messing with these parameters in real-time.

I’m not so sure a Static machine wouldn’t work just fine. Dateline has said that he only uses the static machines himself.

I’m not so sure a Static machine wouldn’t work just fine. Dateline has said that he only uses the static machines himself. [/quote]
It’s subtle, but there is a difference (Page 65 of the manual):
Apart from Flex samples being loaded to the RAM memory of the Octatrack and Static samples streamed from the Compact Flash card, a few other differences between the two machine types exist. The track LFOs can not modulate the STRT parameter of a Static machine. The crossfader can, but if the modulation is too fast the Static machine will not be able to update the start point position correctly, resulting in the sample not being played. Once the Static machine catches up the sample will be played back from the correct start position. Parameter locking
the STRT parameter will however make the sample play back exactly according to the locked position. Flex samples do not experience these limitations and will always play back from the correct position no matter how heavily modulated the STRT parameter is.

Thank you so much to all of you for your comprehensive and clear answers. I guess I’ll start saving money towards an Octatrack to replace the computer.

One last question: can I control these Flex Machine parameters with a MIDI Controller? I guess I can, right, when I assign them as Playback parameters, which are MIDI controllable.

I see the Octatrack as the centerpiece of a larger hardware performance setup that will also include a Korg Volca Sample and the wonderful microgranny (Bastl Instruments) as well as a few synths, and MIDI Controllers (Lemur, QuNeo, Novation Remote 25SL).


I haven’t tried controlling those parameters myself yet, but yes, you can control those parameters with CCs. Take a look at Appendix C in the manual. Playback param #2 and #3.

Cool. Thanks glaciertree. So all my questions are answered. Now time to start saving money. :slight_smile:

I think with the faster compactflash cards that came out since Octatrack was released in 2011, this should not always be a problem.

It’s Dataline, by the way :slight_smile:

True, and not a big deal anyway, I mean in the sense that if you find a Static machine does have playback issues during a wild modulation of the Start/Length params, then just switch to a Flex.

Typically, that’s what I do: if I know I’m gonna mangle a sample to hell and back, it goes into Flex, otherwise I use Static.

Thank you poonti. As the samples I will end up using will not be long ones, I think Flex machines, being limited with the on-board memory as far as I know, will be more than enough for me.

Please note, OP! I didn’t see this mentioned in the thread anywhere. There’s a distinction not yet made here that could frustrate you if you’re anal retentive like me.

The OT has great modulation options for all lockable parameters BUT loop point is not one of these, probably because not all samples have loop points. You can only modulate start point.

That said, you can change the loop point in real time, but that’s in the sample editor. More interestingly, you can modulate start point, and if you’re using retriggering, that effectively becomes your loop, even when your sample doesn’t have any looping in it.

Things quickly get more fun/freaky from there. Just bear in mind the OT is far removed from the traditional sampling paradigm in mostly a good way, but you have to get its voice architecture in your head before it starts to make sense and you get the most out of it. There’s things the OT can do that nothing else can, and there’s things other samplers do that are awkward on the OT.

Hi license,

Thank you. So here is the question then:

What I do in Ableton Live is:

  • I put a sample in Simpler
  • I turn Loop on
  • I assign Start and Length to MIDI CCs
  • trigger the sample with a MIDI note and play around with Start and Length

This turns into a simple granulator, with which I can play one grain or many consecutive grains by means of an arpeggiator. I also control Transpose sometimes, depending on sampled material.

Can I do this on the Octatrack? I see Start and Len parameters in the Playback screen for Flex machines. Can’t I assign them to MIDI controllers or control them live on the Octatrack?

Can one actually trigger samples on the octatrack by sending MIDI notes to it?

Yes to all those questions.

Great!! Thank you!

Great :slight_smile: