Ableton Live PitchLoop89 Masterclass With Robert Henke Pt 1

[Applause] [Music] [Applause] my name is robert henke and i'm one of the ableton folks and i like to talk with you about a max for live device called pitch loop 89 i built and which is available as part of live 11 and this device is highly inspired by a piece of hardware which i have right here this is the pipley saw dhm89b2 [Music] publisher is or was a french company who in the late 70s started building this pretty much a job of one person and a highly highly impressive piece of engineering as you can see here there's tons of integrated circuits in this machine and i'm deeply impressed from an engineering perspective by this box but i'm also impressed by how it sounds and i made the plugin because pretty soon after i bought this machine it broke and whilst it wasn't repair i thought maybe i can build something in max that is a bit similar to it i took a few of the aspects of it that i really liked and added a few things that were technically not possible with this design back in the days to build something that is influenced but a different take what you see here is it's highly symmetrical so you have two channels this is the parameters for the left channel this is the parameters for the right channel and these two channels are mostly independent and i say mostly independent because for technical reasons in the highest sampling rate this thing only has one single analog to digital converter so the input signals from the left and the right channel are mixed and this is especially important for the feedback and i come back to this when we talk about the software version because the mixing of the feedback creates some really interesting effects that i recreated so this already implies that this thing has three different sampling rates it has a 40 kilohertz sampling rate a 20 kilohertz sampling rate and a 10 kilohertz sampling rate so by switching between these sampling rates i can change the maximum delay time but i can also create an instance pitch shifting of an octave and i'm degrading sound quality because with 10 kilohertz sampling rate this sounds really crunchy uh and lo-fi um probably back in the days this was not desired with 40 years of distance this is a sound that is very specific and very unique and that's a good reason to replicate it let's have a look at the parameters here there's a vibrato option okay this can kind of modulates the the pitch shifting um i will talk about that um later there's the delay button which is not in use in the pitch shifting mode so we can forget about it and there's these two controls for pitch chorus and fine and if we are in the pitch shifting mode we see here in the display the resulting pitch and if i want to transpose the input signal i have to adjust these two knobs to go to the desired final pitch it's worth noticing that this thing has no microprocessor which is pretty insane all the calculation it does it does with this crazy amount of integrated circuits since it has no microprocessor it also has no preset memory or something like this which means if you want to go from one setting to another you have to adjust the parameters by hand and this is again something that is both a limitation but also a chance because you will never get exactly the same results and therefore there's a big chance that you find some new results on the way it's also nearly impossible to adjust the left and the right channel exactly the same because well it's analog knobs and there's always a slight derivation all those things make this unit a little bit more alive than what you usually would expect from a perfect pitch shifter it does an excellent job in pitch shifting because the person who pretty much all alone invented it did implement some sort of very clever self-similarity search so that whenever the sample has to be sliced in order to find a perfect point for the pitch shifting to happen it looks for the best possible point in time i'm using a derivation of his method in my own device and unlike in the physical unit i have a switch to turn it off i will talk about this when we talk about the software version so we have the page shift here that is clear and we see the pitch shift here in the display and we have these two knobs here and they are at the core of what makes this thing special to make pitch shifting happen you have to put sound in a delay line and then you read it out from the delay line at a different speed which means the delay either grows over time or it gets shorter over time and you can't do this for an infinite amount of time because you would either need to read in the future or you would exceed the maximum memory so what you do in practice is you do a little bit of a delay and then you jump back and do it again to make the jump inaudible you use two delays and a crossfade in between and these points in time where you start with the readout and how long you read out and when you jump back is defined by these two knobs here called cross point 1 and cross point 2. the difference between these two cross points defines the segment that is looped basically to make the pitch shifting and if the cross point two is closer to the start point than cross point one actually as a result the the data inside this segment is played backwards and on the hardware you see a red led for reverse going on and adjusting these two knobs is pretty interesting and creates all sorts of results because it will it influences the delay the overall delay of the pitch shift but it also influences the sound um if you have very long periods for the delay you get some really really strange things happening with rhythmical material because you basically create some rhythmical cut up um if the time between those two segments is very short you get much higher accuracy for rhythmical stuff but the price is that harmonic sounds might sound a little bit unpleasant too so or interesting or modified which means by changing these two knobs you change a lot of the behavior and what i forgot to mention is there's a memory latch button here which essentially freezes the whole signal and that means whatever is in memory at a given point in time then is played back as a loop and you define the start point of the loop and the end point freely without quantization or as anything like this and this is a lot of fun and you have this for two channels independently that's pretty much the the story of this unit and there is a keyboard for this unit too which is extremely rare and unfortunately i don't have one the keyboard allows to transpose these things on a musical keyboard it also allows to automate the movement of this segment to get some semi-time stretching effects again late 1970s very very impressive and i added a few things in the software version to compensate for the lack of the keyboard and give it a more modern twist so let's have a look at the software version of pitch loop we have a very basic setup here operator playing a flute sound and one instance of pitch loop which currently has a transposition of zero semitones and a delay of 173 milliseconds and a dry wet setting of 50 as a result we're gonna hear the original flute sound and the delayed version right uh things get of course more interesting if we start transposing so let's turn the pitch shifting seven semitones up and we get the desired result for normal pitch shifting we want to minimize the delay so i set the position to zero as you notice the result in the display is not zero but 46 why is this the case it is the case because the pit shifting algorithm needs some time to do the pitch shifting especially if you want to pitch up because pitching up means the delay needs to be read faster than it's written and this would mean writing in the future which is not possible and therefore you have to have a delay so the delay is a function of the segment length if the segment is shorter then this can also be shorter but that means also you have to have more segments all the time running and this means you get more artifacts there's a trade-off between the length of the segment and the quality of the pitch shifting but since this is a creative effect it's not necessarily said that shorter segments are a bad thing or longer segments are a bad thing it really comes down to what sound do you put in and what results we want to hear let's play with it [Laughter] so we can hear that if the segment is very short we get some slight artifacts there and it's possible to create scenarios where it's getting really clicky or sounding really really wrong but i decided to leave all these possibilities in because some of these glitchy artifacts that can be created including clicks and strange noisy behavior might be interesting too and i didn't want to restrict the device to something that sounds perfect and smooth all the time so let's play with it a bit more let's change the transposition to five semitones [Music] and here you start to clearly hear the artifacts that are introduced by the pitch shifting and you also notice that the segments time here is sometimes jumping from 6 milliseconds to 12 milliseconds this is because the algorithm tries to find the perfect crossing point and this artifact can be desired or it can be seen as something that you don't want in that case you can just turn the automatic zero crossing finding off with this little button here and now you get a very static situation which in some cases might be better but let's go more experimental by adding some feedback and make the segment time longer [Music] so this is where things starting to get interesting i'd like to talk about this routing options here at the moment left channel and right channel are completely independent if i change this to sum then the output of the left channel and of the right channel are mixed together before they are feedback in so if i change one channel to seven semitones and the other channel to five semitones then the output of those two pitch shifters are both feet in back into both inputs which means with the sum option at the end of the routing we get very quickly very complex cluster-like pitches so let's try this [Music] [Applause] [Music] [Music] nice whilst we are here we should have a look at a few other settings the most important one here is the short versus long one the difference between those two settings is the maximum delay time and the maximum length of a segment historically this was in because short was everything that was possible at the beginning and then they added a memory extension and they allowed for longer times the longer times are not so important for classical pitch shifting but they become interesting when we are starting to loop things and free stuff [Music] [Applause] there's another setting here which is back which means the segments are played backwards [Music] [Applause] [Music] [Applause] there's also a low cut and a high cut filter which is very obvious in its function and [Music] can be useful for shaping the result there's a few details that have to do with the pitch shifting that i find worth mentioning the fine tuning parameter here is inverted if i change it on the left channel and the link left to right channel button is on then the change on the right channel is in the opposite direction a pitch loop makes a pretty good chorusing device as a matter of fact so if i slightly change this pitch here in different directions on the left and right channel without feedback and with a short delay we get [Music] so [Music] some nice chorusing effects where pitch loop in my opinion really starts to make a lot of sense is when using with some real-time material that is captured on the fly and processed and also especially when it's in looping mode where the input signal is frozen you see on the left side these big buttons with the infinity sign and they actually mean that whatever comes in is kept in the memory and the playback just like some sort of rudimentary sampler is happening with this material let's try this out so i have prepared a little bell here and already we can hear from the speakers that there's feedback going on going on and i'm using the sound of the bell and the feedback of the speakers and and since this makes a sound even when i'm not doing anything i will just for a while play with it and then explain what i did [Music] [Music] so what did happen here a few things one of the things was that i changed the bandwidth setting at the end to make it sound really crunchy and vintage digital and you notice that the frozen signal then also shifted and octaves down until we got this really nice bassy version of the original bell recording and i was playing with the position or more precise the effect was playing with the position because there's two parameters here built in for manipulating the position automatically the first parameter is random which just applies a random variation each time the segment is played back and the second time is an lfo with several waveforms including waveform i call move which is a slow random movement over time and by doing so this whole thing creates very interesting and very alive textures and maybe we can just try to explore this again with exactly the same material and see what we get out of it and what i first do is i apply some initial pitch shifting to create already a complex timbre and afterwards i loop it once the timbre is stable and interesting and then i go further in the processing from there let's try it out so it's a mix of my voice and we make this pitched higher and the longer segment and uh it's so much better to hear your own voice if it's transposed so and we do this and we make it 20k so we have all these amazing things going on here [Music] [Music] [Music] so so [Applause] [Music] [Applause] [Music] i forgot to show something that i find important and this is the capability to actually use midi to transpose the pitch it's a bit of a hidden feature but nevertheless worth knowing i take my bell in again and record some stuff that i turn into a drone and maybe i do the seven semitone five semitone inor john hassel sounding stuff again without the flute this time [Applause] [Music] [Music] that's an interesting example where actually the the filtering is handy since this has been recorded with the built-in microphone of the laptop in a noisy environment because the fan is spinning we have some low frequency rumble in here so i can just get rid of this [Music] by applying the high pass filter and the signal is left over which i want to have but what i wanted to show you is how to control the pitch shifting via midi here's a second midi track and this is completely empty it's just there for routing and it takes all inputs so including the computer keyboard and as a target it shows real time which is the name of my track here containing the pitch loop and if i set it to real time then i got this nice chooser here with 16 channels of pitch loop which all don't matter so we just choose channel one and i enabled record here or i turn the routing to in [Applause] and as you see i can just transpose whatever happens inside pitch loop using the keyboard [Music] [Applause] and this is added to the internal transposition so i can still detune things or apply any other transposition let's try that [Music] i try to find a part of the material that i like a lot and then [Music] yeah maybe this one [Applause] [Music] as you can see here as a side note i deliberately do not limit the transposition via midi so now i'm 54 semitones below the original pitch if this is useful or not i completely leave to the people doing it because even if it only creates strange artifacts it might still be useful so let's transpose this ridiculously high up [Music] well i think this was a semi-convincing example of the complexity you can get out of this by manipulating a very reduced number of parameters i'm not going to talk much about the vibrato section in this video it does what you would expect it adds some vibrato might be useful or not i use it not that often to be honest but i wanted to edit because it's in the original what i find interesting in usage is the filtering especially when working with lots of feedback and what i obviously enjoy a lot is all this random modulation of the precision in the next example i'm going to try the same thing with some rhythmical material to get you an idea what it does if you do the same thing with a drum loop and freeze it [Music] [Music] so [Music] [Music] you

Channel: Synthtopia

Views: 7,869

Keywords: Ableton, Ableton Live, Synthtopia, PitchLoop89, audio effects, DAW, Live 11, delay

Id: mgywmL8Kh94

Length: 30min 56sec (1856 seconds)

Published: Mon Aug 16 2021

Reddit Comments

[u/Marie_Orsic]

Part 2

Robert Henke is one of the original developers and founders of Ableton Live and is still one of the most forward thinking techno musicians around. He is responsible for many of the devices in Live, has built his own controller (known as the MonoDeck), worked as a mastering engineer at Dubplates and Mastering, released music on Chain Reaction and lately he has spent his time playing with lasers and old computers. Without this guy the vast majority of people here wouldn't be making music. Well worth looking into some of his music and lectures.

[u/Periple]

Thanks for sharing!