Drum Loop Tempo Incorrectly Guessed By OT2?

Elektron Gear Octatrack
1

Hi Everyone,

I have a question for experienced users.

I set my project tempo at 95 BPM as the drum loop I was using was at that tempo.

However, when I brought the loop in it was not playing in sync.

I assumed that perhaps the quoted tempo in the sample name was incorrect and ended up time-stretching the drum loop.

I later realised that perhaps the OT2 had calculated the original tempo of the drum loop as being slower as I saw “87” in the sample slot.

My question is - did I do the right thing or should I have adjusted the “original tempo” in the AED? Would that have solved the problem?

I have read of problems with the Octatrack miscalculating the original tempos (tempii?) of loops.

Many thanks in advance for any advice!

Les

2

If you disable timestretch in SRC Setup (TSTR off), the loop will be played at original tempo, if sample rate is 44.1 khz.

Edit : likely wrong sample rate problem : 95 x 44.1 / 48 = 87.23 bpm

OT calculates tempo from power of 2 lengths : 1, 2, 4, 8, 16 bars for instance. And the calculation range is 85 / 170 iirc in the manual (different in reality from my tests).

So if your loop has a particular length, you’d want to change TRIM value in AED > ATTRIBUTES.

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3

This is very important though with OT, correct?

yeah, this lol.

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4

Right - the sample came from Yurt Rock and was at 48 khz so I guess this was the problem and not a fault with the Octatrack.
I’m guessing there’s not an easy fix within the device and that I would have to use something like Logic to change the sample rate or just live with the time-stretch. It’s not so bad with a drum loop as it would be with a melodic loop like a Rhodes etc.

Thank you for your help

Les

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5

Yes. Almost a semitone pitch change…
And I’d avoid timestretch.
Btw I noticed that artefacts are reducted if the pitch correspond (pitch corresponding to vinyl behavior). For instance no artifacts with tempo x2 and pitch +12 (tested with phase cancellation). But OT pitch isn’t precise, nor tempo.

6

Correct.
Any DAW or audio editing software (audioshare) will convert resolution.

Octatrack manual does state clearly it reads 16 bit, 24 bit, 44.1khz samples.

While you can techincally play 48khz samples, they wont play back as intended. Again, as the manual states, with any sample loaded into the machine, when browsing samples, look for the smiley face, if its smiling, that sample is the right format, if its sad, check the resolution or bit rate.

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7

I have some samples from them.
All 48khz…
I didn’t notice that at first also, so you’re not alone…
I use the free web app Digichain to batch convert them to 44.1 kHz while chaining them together for Octatrack sample chain goodness.
I recommend the program… it makes it very easy and it’s created by fellow Elektronaut @brian3kb .

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8

Thanks for your help everyone. I have updated my video (Video 4) so that no-one thinks that the problem was due to the Octatrack.

User error - although the sample in question was on my Compact Flash Card when I bought the OT2 used. I’ll be more careful in future.

I use Samplism on my Mac which does have the option to convert 48 kHz samples to 44.1.
I will definitely check out Digichain - thanks for the heads up.

Best wishes everyone!

Les

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