Mobius As Sampler

alexs1

Hey, all!

Recent conversations about things like "505 Mode" and time stretching made me think how Mobius could potentially be used more like a sampler than a looper. Granted, the line between the two isn't always hard-cut, with many hardware samplers including a built-in looper or vice versa. The main difference to me though is less technical and more about the way(s) samplers are configured as a tool for certain kinds of electronic genres and live performance situations.

Mobius can accept .wav file samples to be pre-loaded into tracks and already has many features that a sampler-artist might enjoy, such as retriggering, multiply, reverse, pitchshift, and so on. Besides those functions, having tracks in Mobius routed out for audio processing (either by plugins or outboard gear) can accomplish much of the rest of what a sampler can do in terms of editing like EQ, adsr filters, etc.. In fact, there has been previous talk on the forum about iterative routing for processing audio in plugins outside of Mobius and then going back in real-time, which would definitely be productive for a hypothetical sample-mode. I don't even think Mobius would have to go as far as forming a library or file organizer for the audio bits, since a lot of that can also be done outside the program and save a lot of extra menu-digging.

While it is already possible to use sampler-like techniques within Mobius, I wonder if there could be any development into certain areas that would further enhance using it this way? For example, one thing that popular samplers like the OP-1 can do is varispeed adjustment for pitch shifting. This produces a really cool effect, and it's been discussed before as a potential alternative to the limits and challenges of zero-latency/artifact timeshift computation in Mobius. In addition to varispeed, the other really fun "key" feature of samplers is that you can play back the recorded audio as re-pitched notes on a keyboard. I could see that being an awesome way to use Mobius, too, by either 1) pre-loading a short sample or 2) quick-recording a sample that could respond to a MIDI or computer keyboard to be played in scales, where press and release values determine the duration of audio playback (depending on where you have it set to begin). You could also introduce certain variations on existing recording functions that cater more to capturing audio like a sampler, i.e. something that once recorded, puts the loop in a pause/rewind stop (as if it were just imported). Finally, returning to our thread on Drag n' Drop, it might help to build that bridge down the line so that deeper sample processing can be done in the DAW and smoothly brought back in for live-performance situations.

Not to add anything to your full plate, Jeff! This is just to float the topic and maybe imagine a possible direction for Mobius that might make it a valuable tool for some musicians who utilize hardware samplers. I would love to hear if you or anyone else here has any ideas about this!

davedraper

alexs1 Well I haven't dived back into mobius too much yet, but the functions 'start', 'stop', 'pause' etc seem to be new to it, compared to the old mobius. One of the 'shortcomings' of Mobius2+ I felt at the time was that the looping engine was always running, and I wanted to sometimes just play/replay one-shot samples as part of my performance. It seems that will be possible in the new version, though whether one can retrigger track 3 (say) whilst tracks 1,2 & 4 continue playing (perhaps) will require some investigation/scripting I guess.
The old mobius 2 used to do a speedshift (like varispeed) I remember, in cents? I seem to remember changing it + or - up to 4096, or 8192 I think, so it could be quite finely tuned, but only on the fly. As Jeff has written, true pitch-shifting is unavailable on the cheap, but I have a lot of fun using varispeed in sample manipulation these days! 🙂
Multitracking loads of pre-recorded samples however (using MIDI maybe?) seems a bit too close to reproducing a DAW perhaps?
Dave

jeff

I go back and forth on this. Internally a sample is just a loop that plays from beginning to end then stops. So why not have a "sample track" that just holds a bunch of one-shot samples and let you trigger those, either one at a time or overlapping? It's relatively easy to do and I use it all the time to inject content into loop recordings without having to actually play an instrument.

Then I look at things like Kontakt and get humbled. It's really not worth my time to reproduce all that. So I'm trying to find the line between something that makes sense for me to do vs. trying to get into the Sample Player business that already has a bunch of established options. It's similar to pitch shifting, do I try to do that myself or find ways to more tightly integrate with things people already have.

What is currently called Samples won't go away because I need that for testing and I don't want to stop and wire together Mobius+Ableton+Kontakt every time I want that. Another example: I've been working on a Metronome. Where do those beat sounds come from? They're samples you should be able to load.

So I suspect it will get more powerful than it is now. But it won't get to where you can visually trim start/end points, apply effects, do complex keyboard mappings, or arrange them in sequences.

alexs1

jeff

Yeah, software samplers like Kontakt are very extensive, even compared to what most hardware can do. For Mobius, I was picturing something more minimal. A close model perhaps is Chompi, where the sampler functions are stripped down to the essentials. In Mobius, if you exclude things like effects, sequencing, trimming, waveform shaping, sample libraries, and interface organization, you are already left with the majority of what a sampler can do out of the box (one-shot, multiply, etc.), given some light scripting. The rest can usually be accomplished through routing integration/processing with a number of external tools in plugins/DAW/gear. As I see it, the two apparent remaining features that could put Mobius on par with most standard samplers are varispeed adjustment and re-pitching for keyboard triggers. You've mentioned varispeed before as an option for addressing the shortcomings of what was previously timeShift in 2.5; is that still on the table (further down the line)? And for the latter, is it possible even to have that work (i.e., recording a loop, then pressing a note on a keyboard that would play back at the corresponding pitch)?

Moonchurch

I had some scripts that would allow me to record a phrase, end recording in mute.
Then another script to play that loop as a one shot from the start.

alexs1

Coming back to this, I think the best approach might be to just use an external sampler in conjunction with Mobius to achieve the desired workflow for live situations. For example, Serato Sample is a plugin that can integrate with DAW routing and is equipped with all the proper DJ tools, or a hardware like OP-1 and MPC One that can integrate with your looping through an audio interface. As for the former, that might be fun if Mobius ever supports plugin hosting. But per this thread, i.e., endowing Mobius with sampler-like abilities like one-shot keyboard pitching, sequencing, and timestretching, it seems like a moot point when it could be made simple to just choose your favorite third party sampler for live performance. Aside from that, I would still be interested in if Varispeed could be added later in development as a creative alternative to some of Mobius’ current pitch-related functions. I might post a separate feature request topic on that too.

jeff

Varispeed is already in there, for normal loops. It doesn't work for Samples, but it does for any normally recorded or loaded track loop. It would be trivial to add for Samples though. The main thing missing is a way to trigger that with a range of keys rather than just a single MIDI key binding. There was an old feature called "spread range" that was intended to do that, for use with the PitchShift and RateShift functions but its probably broken. The idea there is you would create a single MIDI key binding to RateShift and this would automatically extend out in either direction from that center point. The key the function was bound to would be zero or "no shift" and if you pressed keys on either side of that the rate would go up or down chromatically. If that's what you're looking for I can dust that off and see if it still works.

alexs1

jeff

Oh, I didn’t realize Varispeed was already in there! Is that what RateShift and PitchShift use?

I remember reading about the spread function in 2.5 but haven’t tested it out yet in the newer builds. Afaik, that would essentially be what keybed samplers do. That could be cool natively in Mobius for quick transpositions, and would maybe leave the rest of pitch stuff like varispeed tempo modulation to external samplers.

jeff

Yeah, I use the terms rate and speed inconsistently. They're the same thing. The functions have "Speed" in their names and the related parameters also have "Speed". SpeedShift speeds up or slows down the loop which means the perceived pitch changes but the loop length also changes. The most popular one in that family is Halfspeed which makes it twice as long and an octave lower. SpeedShift takes an argument that is a positive or negative integer to control how much you want to change. It changes the speed so that the pitch changes in chromatic steps. So SpeedShift 12 is the same as Doublespeed and SpeedShift -12 is the same as Halfspeed. SpeedShift 5 is up a fifth, etc.

The functions with "Pitch" in their names are disabled at the moment. These used to do what most people think of as pitch shift, changing the pitch WITHOUT changing the length of the loop. That's a lot harder. Pitch changes with varispeed is much easier.

If you bind it to a CC rather than a Note then you can go up or down with a continuous sweep rather than in scale degrees. I haven't tested that in a long time. The old code is still there, but everything around it has been changing a lot, so it may not work right. But it should be easy to fix if it doesn't.

alexs1

jeff

Coming back to this thread after having tried SpeedStep on Build 41. I'm having some trouble getting it to work as a ranged function when binding it to a MIDI Note (C3) and leaving the argument field empty. The Step Range is set to 24 in Overlays/Effects, but when I press C3 or any key chromatically on either side of it, there isn't any result in the loop.

jeff

Yes, Step Range is broken. There is another old parameter speedSequence where you count enter a list of semitone values in a string, "2 5 -5 0" and sequence through them with SpeedNext and SpeedPrev, but that's also missing. Will work on restoring those.

alexs1

jeff

Is there any Speed feature that can adjust the loop length according to tempo changes (even if it also adjusts the pitch)?

jeff

Not yet, but we're pretty close to that. When a MIDI track uses the follower options to resize itself based on the length/tempo of another track, all it is doing is adjusting it's playback rate, in much the same way the Speed functions work in audio tracks. Audio tracks could do something similar, though it's a bit more complicated since we're dealing with a continuous stream of samples and latency compensation rather than just moving a few MIDI notes around in time. But it's basically the same as SpeedBend, it just needs to be able to use the Sync Source as the control control source rather than a MIDI CC value. Definitely on the list.

alexs1

jeff But it's basically the same as SpeedBend, it just needs to be able to use the Sync Source as the control control source rather than a MIDI CC value. Definitely on the list.

Great to hear!