 Hello OscillatorSync here, and today we're back with the Korg Ops 6 and exploring the idea of building different synth architectures within the Ops 6. In previous videos I've tackled the idea of building a Juno style synth and a rather more peculiar and strange Buchler music easel style architecture inside the Ops 6. Today's video is going to be a little bit different in that I'm not going to try and build a specific synth. Rather I'm going to focus in on a feature that is common to a bunch of different instruments, and that is the idea of building a filter bank in the Ops 6. So first things first, what is a filter bank? Well if you've been around since a little bit, you've most certainly come across filters because they make up one of the primary parts of a subtractive synth architecture, which is probably the most common type of synth that you're going to come across. In terms of the different types of filters, of course we have our low pass which is probably the most common type of filter where anything lower than the cutoff is allowed to pass, hence low pass, and anything above it is cut off, so by turning the filter down we get a darker sound. Probably the next most common one that you will come across is a high pass filter, which is the other way around. So everything higher than the cutoff will be allowed to pass, hence high pass, and anything below it is cut off, so we turn up the cutoff to get a brighter, thinner sound. They're probably the most common ones that you come across, but I've recently become very, very enamoured with band pass filters. Band pass filters, rather than letting the lower or higher frequencies pass instead, cut to the lower and higher frequencies and just allow a band in the middle to go through instead. It's a super cool sound, especially when you start to add that lovely, windy resonance in there. I've really got into band pass filters, especially since getting into modular. They're just very, very wonderful things for a whole different set of reasons to high pass and high pass. For the sake of completeness, you also get band reject filters, which is kind of the opposite to band pass wear, rather than allowing a band through, we cut out a band. Again, it's a very cool sound if you are into phases, you're immediately going, yes, I like that sound, of course. That's not what we're talking about today. The filter that we're focusing on is the band pass filter, because a filter bank, generally speaking, is made up of a bunch of parallel band pass filters. That is, you have a signal, which is split to a bunch of different filters, all set at different frequencies, typically fixed frequencies, but of course we don't have to live by those rules. You add a little bit of resonance to each of those bands, and then by combining the relative levels of those bands, we can get lots of different characters from our sounds. It's kind of like, sort of like a graphic EQ, but without trying to be quite so clean, neat and tidy, a lot more sort of character and ring generally introduced by these resonant band pass filters. So in terms of where you will find filter banks, they're wonderful for creating this kind of interesting ringing character to sounds, but they seem to be especially adept at doing kind of vocal sounds. So one place you'll certainly find a filter bank is in a vocoder, which is basically just a filter bank where each filter has an envelope follower associated with the modulator signal and then VCA to apply those same bands to the carrier. But also in terms of vocally sounds, you'll find this kind of setup on string machines for the vocal parts on the string machines, especially good when paired with chorus, the Vox Humana sound also based around a filter bank. Lots of interesting vocally sounds seem to be very, very easily pulled from this setup, and it's certainly quite evocative of a particular age in electronic music. I think there's a certain classic sound that is associated with anything you put through a filter bank. They're also found in big modular systems, and I certainly would love a nice fixed filter bank in my system if I had more space perhaps for doing all sorts of, as I say, sort of characterful ringing manipulation of sounds. Right, so that's what they are. That's where you may find them. How are we going to build it in the up six? So our plan in this case is going to be a lot simpler than the previous two videos. Really, all we need is a single source, which we're just going to use probably an FM operator for, and then that is going to be sent into all of the other remaining five operators, all of which are going to be set to filter mode, bandpass mode, and set to different frequencies. Each of those can then be sent to the output. We'll also want to make sure on all of these that we turn down the oscillator mix so that they are not generating any sound themselves, rather just passing through and filtering the sound coming from this top operator. So let's jump to an initialised patch and build this. So as always, if we're working with the user algorithms, we're going to head to the homepage here. We're going to turn up the algorithm all the way until we get to user. There's no built-in algorithm that replicates this weirdly. I kind of thought there was, but there isn't. So on to user algorithm, and then we'll go into the miscellaneous menu, come down to user algorithm and press yes to come in here to build our algorithm. So the first thing we probably want to do is go on to page two here and we're going to choose which of these operators are going to act as outputs. And in this case, it's everything other than operator one. So operator one, we can leave on off and all the others we can turn on like that. They've all turned red telling us that they are a carrier and an output. So come over to the other page here and we can start building our algorithm. And again, it's going to be a pretty simple one to do. It's just going to be each of the operators has one going into it and one isn't doing anything. So at the moment we're on operator one, which we don't need to do anything to move to the next operator. We want one to go into two. Next one, we want one to go into three. Next one, we want one to go into four, one to go into five and one to go into six. So kind of simple as that. Cool. So we can come out of the user algorithm setup now and we can start building our patch a little bit more. So let's start by going to operator one now with everything else turned down. Operator one isn't going to make sound because it doesn't have a direct output turned up one of the other operators. We would hear something, not the right thing yet, but we would hear something. So operator one in terms of the mode, I'm just going to leave it in FM because that works for me. It requires the least faff to do anything else with it and I'm going to set it over on to SOAR just because a lot of these patches, especially when you're looking for vocal sounds, are going to work best with a SOAR input. At its level and envelope generator, we can address that as we go along. What I'm going to do here is build architecture where the envelope of the synth is dealt with on operator one and the others are basically set to drone essentially. So what I'm going to do is set up one of the operators the way I need it and then copy it across to all the other operators because the only difference between each of these operators is going to be the filter frequency that they're set up at. So we'll come across to operator two which will set on to filter mode and we will choose our filter type. Now there are a couple of different band pass filters available to us. There's the basic band pass filter here. There is an MG band pass filter, which is six pole and one that is 12 pole. In terms of which one you want to go with, I would say experiment and see which one you like the best. The basic band pass filter is very clean. The MG ones are a little bit more characterful, have a little bit more ring to them and they saturate a little bit, which means you can drive operator one into the filters to get different characteristics, which is quite interesting and you get more variation in the sound based on operator one's level as the envelope changes. In testing, I've preferred these MG ones, in particular the 12 pole one, but your mileage may vary. Experiment and see what you like. We're going to turn the oscillator mix all the way down because we don't want to hear anything that this operator has to say. We just want to use it as a filter. So if we now turn it up, we should be able to hear operator one coming through it and be filtered with a band pass filter. So we're going to come into the pitch menu because we don't want operator two to be tracking its filter across the keyboard. And if we're in ratio mode, that is the basic default mode here. That is what's going to happen. We're going to get filter tracking. Things are going to be darker up at the top and brighter down at the bottom and brighter up at the top. That's not what we want. We want this filter to stay still where we set it. So we can move that over to fixed. Sorry, wrong knob there. And now we can choose where it's going to sit. We can fine-tune this as we go along. Somewhere around to 20, it's probably going to be a good low point. Might try lower. Yeah, let's maybe try 190. And the other thing I want to do is just get this filter ringing a little bit so that it's imparting a little bit more character to things. Now, you can do that by ear by just turning up the resonance, but one really neat trick if you want to find the point at which the filter starts to ring is if we come back to operator one and we drop its pitch all the way down so it's clicking. You can hear that now. It's so slow that it's clicking rather than making a pitch. If we come back to operator two now and go into its mode and start to increase the resonance, there will be a point at which we can hear. See how they start to ring a bit. And again, your mileage will vary. This is basically pinging a filter. I liked it in testing when it was just getting a little bit drummy. Somewhere around there. We can come back to operator one now and set its pitch back to. I'm going to leave it at 0.5 actually because just the range of the sounds is a little bit better in this case if I set it there. So now we have that oscillator going through that band. Pretty almost here. There is an interesting vocal quality to it. And you can also hear there's a bit of a whoop at the front there. That's because we've got that filter at that ringing point and it's saturating a bit as well. And that's all just going to impart character. You can dial that resonance back if it's too much for you in a particular patch. One last thing to do on operator two, our first band here. And that is we want to set the level envelope to basically drone. And we'll let operator one do what it needs to do. So we'll set the attack to zero. We'll set the sustain to full. We'll set our release as long as it will go and we'll set the curve to linear. Because that gives us the gentlest release. And now anything that we change on operator one is just going to be reflected in the output of the patch instead. Which is all good. So next thing we want to do is copy that across to all of the other operators and set their relative frequencies. Now we could spend time duplicating that across all of the different operators. But the Opsix actually has in a built-in little feature that allows us to copy everything across. So if we come into the miscellaneous by doing shift and filter, we want to go up to, sorry, down to the op utility here. And now we've got copy op from one to two. That's not what we want. We want from two to three. And we can say yes, from two to four. Yes, two to five. Yes, and two to six. Yes. And now each of those is going to be set up identically. That's not quite what we want. We actually want them to all have different frequencies. So there's our first one. If we bring this up, it's just going to kind of double the output. Not quite what we want. But now that we've set the pitch on each of these to fix, we can use the knobs up here to do pitch movement, which in the case of filter, our operator is going to give us a frequency movement instead. I'm just going to pick up some frequencies that seem to work for me. Something like that. And now we have a filter bank. So as a really sort of basic example of how this might work, if I just play a chord, I can start to bring in these different bands. And you can hear that there's a real vocal quality. And you can get loads of different flavours and characters from this sawtooth wave by arranging the bands at different relative levels. Which immediately is quite evocative for me. But let's turn this into a kind of like a string machine voice setup. So there's a couple of things that we can do to make that a little bit more string machiney. So the first thing and possibly the most important thing I think in terms of getting this to be more string machiney is to give it a little bit of vibrato. So operator one is the only thing that we're actually hearing here. So we can come back to operator one and come into the pitch menu. Tap it again so we can start to apply some vibrato. LFO one. Something like that. And we'll just change the speed a little bit. Yeah, that's nice. One thing, however, that the string machines tended to have or often had on the voice is that rather than having the vibrato always there, it would fade in. They would have a decay on it. If I am recalling the fade on the Opsix fades out rather than in, I think. I know. Quite gone. Fades in. Perfect. A little faster. Cool. Yeah. Okay. Next thing we probably want to give it a little bit more of a gentle envelope in terms of the sound coming in. And because of the way we've set this up, we can do this entirely inside op one rather than having to duplicate envelopes across multiple operators or anything. So we can go into level, we're on operator one already, and we can start to set a... It's such a vibey kind of retro. Those two are set too close to each other. Now strictly speaking, if we wanted to turn this into a proper string machine, we'd want this to be paraphonic. But there's simply no way of doing it on the Opsix. As far as I can tell, I've tried real hard to find it. And I just can't. If anyone can think of a way to do it, then please let me know. But the poly voice assignment, there's poly, there's mono, there's mono legato. I just can't find a way to make it paraphonic. So we have to deal with the level envelope being articulated separately on each note. So sorry about that. Nevertheless, it's quite an evocative sound, but there is something that is missing, 100% in terms of getting that string machine sound, and that is chorus. Now if I remember rightly, if we come into the effects here, the first one is set as chorus anyway, so we can just turn up the mix a little bit. We can get very different characters depending on how we set the various. It's a nice one. Actually think about it, if we wanted to get rid of our modulation, we could actually, in the pitch menu here, set this to go through the mod wheel. So when the mod wheel is down, so we still have mod wheel control that way. And we can probably get a bit more stream at the top end then, can't we? Please excuse my very mediocre, white key noodlings. It's a really evocative sound. Filter banks always seem to make things sound like they're of a particular age, and it's just a nice thing, I think. Anyway, let's take this patch and do something a little bit more interesting with that. Let's introduce some more modulation to the sound, and I think eventually we'll get to, like, a talking robot at the back end of this. So I think absolutely the first thing that we should try in terms of getting a bit more movement into this is modulate the levels of the operators. It's a really obvious thing to do, but I think it will sound pretty interesting. So what I'm going to do is I'm going to set these all a little bit below halfway-ish. Let's begin with to give a space both up and down with our modulation. In the mod menu, I'm going to set my two LFOs to what? Shall we do some random movement? So it's kind of like a fake vocoder of someone's talking, but they're not really saying anything real. So let's set both of these to random level and time, and I'm going to set it on a per voice basis. So each note played is going to articulate the various different bands differently, which I think will be an interesting sound, and we'll just duplicate that exact same idea, random level and time on the other one as well, voice sync there. Right, and now we can come into our V-patch and start patching those into the various different levels here. So let's start by maybe doing LFO 2, going to operator 2's level, maybe up and down by 50 or so. You start to hear that one fade in and out a little bit. Next one, let's do LFO 3. Let's send that to operator 3's level. Same deal more or less. Start to hear that magic happening. Yes, good. Then we'll come back around to LFO 2. Send it to operator 4's level, but we'll send it backwards, the bipolar. So what we'll get is kind of like a cross fading between these two. So as one goes higher, the other will go low, which will be quite cool. Starting to talk to us. LFO 3 destination up 5 level. Same deal, we'll go backwards on this one again. So these two different bands will cross fade each other. Good. And operator, what we're doing, source. And what we'll do is we'll do LFO 3, but we'll go via LFO 2, 6 level. Let's try that low. We've still got that chorus on the go as well. See now it sounds like some sort of demon throat singing thing going on there, which, depending on what you're into, might be appealing. I think at this point we can also think about adding maybe some reverb and probably some delay as well. Should we put some tape delay on that? And of course we could play with the rate of those as well. We could maybe have one going slower than the other one, and maybe the other one going much faster. We can still adjust the relative levels a little bit if we want. If we want that sort of glottal throaty thing happening there. So here we're more sort of alien singing I think probably. Let's see if we can turn that into robots instead. Now I don't know about you, but when I hear robots I think are a peggiator. So let's engage the arpeggiator and set it to latch and let's just plum in some notes. Now I don't think robots are as gentle as that with our envelope first and foremost. So let's come back on to our operators and let's come back round to operator one, which are on, and let's adjust this operator level EG to be plucky. That's more like it. I might adjust that in a minute, but that's better. That's a bit more robotic. Okay, in terms of the modulation for this, let's go ham with the modulation because that's where the magic is going to happen. And what I'm going to do is I'm going to set my two modulation LFOs. We're going to sit with a random thing going on. We're going to set the sample and hold, which just is straight up sort of random sample and hold, but I'm going to slam the speed all the way down. And what this will do for this patch, because none of the notes are staying around for very long, is basically because this is set to key sync voice, I'm just going to get a new random value each time we press the key. I'll do the same thing on this one as well. So it's not made a whole lot of difference to our patch as is because we're already basically just getting those random bits happening there. But let's break the rule of a fixed filter bank and make sure that these filters aren't fixed anymore because I think as we start to modulate those filter cutoffs, things are going to get rather magical. So we're going to come back into the V-Patch here and we'll leave our level movement going on because I think that's working for us. But we're now going to go and additionally add some pitch movement to the operators and because these are filter operators in fixed mode, the pitch of the operators is also going to be our filter cutoff. So I started with LFO 3 on that one, didn't I? So let's, no, LFO 2 on that one. So let's flip that and we'll go to LFO 3 for this one. Destination, operator 2 pitch immediately. As we let that move around a little bit, things start to get pretty interesting. Let's do the same trick for the next few as well. So this one could be LFO 2, destination op 3 pitch. I'm just kind of arbitrarily setting these just listening to what's happening until I hear something cool. Here we go again on LFO 3 for op 4 pitch. And we'll go down this time because the bipolar, this will also send it high. Yes, it's time to get those little barks up at the top there. Lovely, oops, op 3. So next one, source. LFO 2, go into 5 pitch. And yeah, we'll do 6. 6 is set quite high, so I think maybe we just use 6 as like a treble control. Yeah, I think so. But I think what we will do is get this to pan around a bit as well. So we'll go LFO 2, 5, 3. Destination will be program pan. Because these are set per voice LFOs, this is going to be per voice panning. Sweet. Don't want to get too wide. My little alien robot friends are talking to me. Now I think what will be really really cool here is if we now modulate the decay portion of operator one's envelope. So we get some really short little barks and then some longer ones as well. So again, we'll just pick one of the LFOs, I'll choose 2. Operator 1, we want that going to the decay time. We'll drop that sustain down. Let's try this on a low octave. In fact, let's just have the arpeggiator go across two octaves. Maybe we'll just put the master filter down a little bit. Yes. We'll put them in a place instead. Lovely. Sorry, I'm just having a lot of fun with this patch. Because we can still have a bit of more of an effect over everything by adjusting the relative levels of our bands. Yes. They speak to me. Let's make the decay longer in general. But the LFOs effect a bit more. We've got one more slot on the V-Patch, what do we send that to? We could send it to the octave of Operator 1, couldn't we, or the program octave. So now we've got the two octave range on the arpeggiator, but within that it's swinging at an octave higher or lower on top of it. Per voice. I also wonder whether this will sound better if we set this to mono mode. About the same. Also might be cool. Makes the panning weird though. Bit of portamento. Anyway, I could sit and play with this. Synths are just fun, aren't they? We've got a master filter on it with a... Yeah, anyway. I think we'll leave it there with our little, our new friends, little robot friends chatting away in the background. If you enjoyed this video, if you found it interesting, as always, if you could find a moment to leave the video a like, that's always massively appreciated. Make sure you subscribe to the channel. I've got a plan for the next video, but I need to put some thought into it to make sure I get it right. But I'm really excited for the next video. I'm going to involve the Opsix, but it involves another synth as well. Let's see if you can guess which one it is. If you want to see any particular types of patches on the Opsix tackled on the channel, then let me know in the comments. I've kind of stayed away from doing like a basic bass or lead sound or whatever. If you'd like to see something like that, I'd be more than happy to take something a little less esoteric on. So I do recognise that that's the way I sometimes go. But until next time, have fun with your synths. Whatever synths you may have available to you. And I will certainly hold up my side of the bargain and have fun with mine. But until next time, take care of yourselves. Thank you so much for watching and I will see you next time.