Pitch only based time stretching?


#1

Hi,

I’m wondering if the OT provides some pitch only based time stretching mode.


#2

yeah i think its in the track setting page.


#3

I noticed but it didn’t work as expected.
No matter if I have this setting to Pitch or to TSTR, sample is always maintaining its original pitch.

What I’m looking for is a time stretch/compression algorithm that just re-pitch, like a turntable does.

Anybody knows if the OT can do something that simple?


#4

Well,

The RATE PITCH/TSTR defines how Pith and Rate controls will affect the sample, so if you want to set sample tempo using this you have to do it manually, therefore if you change OT global tempo those samples will be out of tempo.

So far I can’t see any AUTOMATIC way to adjust a sample’s tempo using re-pitch.

Any one please?


#5

This was one of those things I the OT can’t do, if I remember.


#6

Search for SecretMusic’s OT video series tuts - he did one that covers timestretch and I remember he said it was ‘quirky’ so not sure if you’ll get exactly what you need


#7

+1
Unfortunately, no. I wrote to Elektron last year to suggest this. I got a very polite answer that they would consider it. I haven’t given up hope yet that OS 1.3 might provide it.


#8

@Housecliche,
as I said, you can do it manually but when you change global tempo you need to re-adjust settings, nice videos anyway.

@MichalHo,
I hope so, re-pitch is very useful in some situations where pitch doesn’t matter and transient and pristine sound does.


#9

OT buyer q: does this mean you have to work with pitch-retained samples that are magic’d out in length when the tempo is changed and it’s not simple to let a sample fit the length and re-pitch like slowing tape - i’ve asked a related q on forum that has had few takers, but in particular wrt pickup machines - i just want to know will i be listening to samples that are heavily processed ‘to fit’ all the time or can you keep them away from algorithms - i think the majority of my interest will be for non tuned samples so i would not want these being messed with until i messed with them if u catch my drift

any good soundcloud links which look at these aspects, in particular, artefacts from stretching and larger sample handling

maybe i misread the thread, what’s the gist of the issues uncovered ?


#10

The issue is that there are just two time-stretch algorithms and none of them are suitable for full mixes. They add many unwanted artefacts.

Re-pitch is the best for those situations, but it is not implemented as a Time-Stretch algorithm on the OT.


#11

Hmm, that’s rather surprising, thanks


#12

@avantronica
yes, you can turn timestretch off – for individual samples in the editor, or for machines in the machine playback setup page.
many users work with i.e. ableton to prepare samples in whichever way the OT cannot.

@gbravetti
my thoughts exactly. personally, i would have preferred to have a re-pitch algorithm instead of the beat algorithm implemented in the OT.

btw. i found the reply (actually 2 years ago, not last year, as i stated in my earlier post) in my customer zone on elektron.se:

Octatrack Support Ticket No. 59:
"2011-06-16, 16:24 Daniel said

no, not at the moment. we will look if this is a feature that we will implement

thanks daniel"

let’s hope they have not forgotten… maybe you should write them too?


#13

but does that mean you don’t get the sample fitting the length if tempo is changed, and what about pickup machines where the timestretch is forced on ?


#14

when timestretch is turned off, yes.

and what about pickup machines where the timestretch is forced on ?

they get processed using the existing beat/normal algorithms.


#15

Anyway is not my intention to work with full mixes on the OT, now I’m kinda in a hurry because I want to play some new stuff I just made with the OT with old stuff I haven’t time to re build, and that old stuff, I have them as full tracks (full mix waves), and they sounds terrible when processed with the OT time stretch/compression.

@ MichalHo,
I also prepare many of my samples in Ableton and that is ok if you planned to work at a fixed BPM, but then if you need to change BPM for any reason…

Anyway my next step will be at least get a render of those tracks without Kick and Bass, then with the Kick as single sample on another track and the Bass on the A4 the OT time stretching is not that bad.

Another temporal solution I’m just thinking about is to let OT time stretch do the work, then with RATE set to PITCH, manual change Pitch and Rate to get the pitch/tune you would get with a re-pitch only time stretching. I don’t know if Pitch and Rate have enough precision for this, may be they do. I’ll test this in deep next week.

Any way if I change master tempo after this I will need to re touch Pitch and Rate values.

If this “temporal solution” works, it would be very simple for Elektron guys to make this happens automatically.

If you decide to use re-pitch only time stretch, the Pitch and Rate controls get grayed/blocked (because you don’t care about pitch for this sample) and a very simple math calculation adjust them automatically for you.

What do you think?


#16

I don’t know how flexible the sound engine and system architecture is, but it seems they would have to lock the positive values (0-63) of the Rate parameter to the master tempo. This method would only work downwards, and within a small bpm range from the original tempo (assuming steps of 0.1 bpm), as rate can only be slowed (?) and is divided by 128 discrete MIDI values (?).
So I assume it’s up to those two factors, could rate be sped up, and could it have a finer grid than 128 steps?


#17

Actually if you want to do it manually you can get finer values using a combination of both, Rate and Pitch.

I don’t know regarding the internal sound architecture on the OT, but the re-pitch process is the simplest, and it is already implemented, they should provide some way to use it as an automatic time algorithm.

The need of more steps on the Rate and Pitch controls doesn’t matter, they could do it internally, anyway when you are using re-pitch as time algorithm, you can’t change Pitch or Rate manually, it has no sense, so Rate and Pitch must be blocked for the user.


#18

Before OS 1.0 it was not possible to reverse samples with negative rate, so speeding up a sample above original tempo could in theory be possible, but i don’t know how well the CF card would handle this if a static machine were used. So speeding the rate up sigificantly could be technically difficult or dependent on the card used.
Without speeding up being possible right now, only half of the desired functionality of a repitch algorithm is implemented. I agree about pitch and rate having to be disabled in our hypothetical mode of operation.


#19

Right now you can stream several minutes samples at 2x the normal speed using static machines without any problem.

I don’t think there could be some problem, specially for slights corrections like +/-15 BPM.


#20

True! Turning off timestretch and setting pitch to +12 doubles the sample playback rate.
I wonder what keeps them from adding the option to lock pitch/rate per sample to the global tempo.
Is it because of a lack of user demand?