9 ms·

Eurorack Knob Idea

322 points by po 1y ago

d--b 1y ago
It's like real life functional programming. Can't wait for the y-combinator module.
itomato 1y ago
I’m just waiting for the Eurorack Boombox revolution to hit.
diggan 1y ago
Interesting idea for sure, but how is the feel of actually turning the knob? Seems to offer short to no resistance, which would make fast but precise movements pretty hard, something that is important for things like performances. What would be a huge bonus point (but maybe unrealistic? I don't quite understand how the current implementation actually works) would be software-configurable resistance (physical, not electrical). I've spent a lot of time for my DIY modules to find the right knobs, or the right process to adjust the resistance of my existing knobs, being able to control that digitally could introduce a whole new level of fun.
- scottapotamas 1y ago
  You might enjoy https://github.com/scottbez1/smartknob https://github.com/scottbez1/smartknob The complexity of this approach (ignoring the display and flair) unfortunately means you won’t see this used too often due to cost.
  - diggan 1y ago
    That's so cool on so many levels, and I really enjoyed that indeed, now I have to fight the urge to try to build it myself, good thing it's weekend. However, it does seem to miss the single most useful feature (for me) which is the resistance part. I understand there is a DC motor controlling the snap points and whatnot, but what I'd like is constant resistance I guess, to a configurable level, rather than snapping to specific points and such. I don't think it would be possible to hack on top of the already made hardware, but didn't seem like it was already done in the software side of things, although I did skim through things so maybe I missed it.
    - pakue 1y ago
      Should be doable to add that. The BLDC needs to add a proportional (or any other function) force against the rotation direction until it reaches 0.
      - diggan 1y ago
        Sounds reasonable, wonder how that would actually feel in real life? As far as I understand, this would pass through digital parts, adding a little bit of (maybe noticeable) latency, but I wonder if the latency gets high enough for it to be a bit jarring that the resistance is dynamically changing as you apply torque.
        scottapotamas 1y ago
        This is all fairly normal in robotics, under a subset of (slightly overloaded naming sorry) “impedance control”
        camtarn 1y ago
        In practice, when latency is small enough (on the ~1ms level, which is trivial to achieve using even pretty cheap parts) it's imperceptible. I sometimes develop control loops for prototype systems which use a motor to emulate a combination of spring + friction damper, and even though I know that my code only runs every 1ms, it's really remarkable how much it feels like a real continuous analogue system. Another good example is power steering, which uses a motor to remove resistance instead of add it. If I understand it correctly, it senses you applying torque to the steering column and adds proportional amounts of boost - but because it happens so fast, it just feels like the steering is magically lighter.
  - adolph 1y ago
    A differently complex and smaller approach might be to combine the knob with with an axial flux PCB-BLDC, like what Carl Bugeja made [0, 1]. It might be suited to get haptics in something as small as the article's knob, although to get an in-built display you'd have to use one of those displays that fit in lego bricks [2, 3] with a slip-ring. 0. https://microbots.io/products/motorcell https://microbots.io/products/motorcell 1. https://www.youtube.com/watch?v=CVszJMlvZcA https://www.youtube.com/watch?v=CVszJMlvZcA 2. https://github.com/AncientJames/uGrey https://github.com/AncientJames/uGrey 3. https://www.youtube.com/watch?v=0pUV_3qeHog https://www.youtube.com/watch?v=0pUV_3qeHog
    - diggan 1y ago
      Many thanks for the links/references. I don't really care about the display itself (probably prefer without it actually), but never saw those other links before, interesting stuff.
  - weinzierl 1y ago
    My dream is a piano keyboard with entirely software controlled mechanical key response. Every key individually mounted on a servostepper. As a bonus it could be used as a fake player piano. Or for practice you could make the wrong keys hard to press. Endless possibilities.
    - Q6T46nT668w6i3m 1y ago
      Great idea and I’m shocked this doesn’t exist.
      - robotresearcher 1y ago
        It would likely be very, very expensive. A compromise that is affordable and does exist is programmable response curves to key velocity and aftertouch pressure. It can make sense to have different curves for eg. piano vs harpsichord even if you can’t change the mechanical key impedance. I haven’t seen it in the wild, but using this you could make the wrong notes quieter/louder or even play a different sound. But I think we all know when we play a wrong note, so the utility might be small.
        mrandish 1y ago
        > key velocity and aftertouch pressure. Just a tangential note to say whenever I see these terms in discussion of MIDI keyboards it reminds me how disappointed I am the vast majority of MIDI controller (and multi-thousand dollar flagship synth) keyboards still don't fully support per note velocity or polyphonic aftertouch. It's only been 40 years kids... (sigh).
        otabdeveloper4 1y ago
        Not really needed. A synthesizer is not a piano, it's essentially a wind instrument.
        lsaferite 1y ago
  - hinkley 1y ago
    This is what cars need. Only make the entire dial depressable instead of the embedded screen. Use different haptics for each setting so you can feel which setting you’re changing.
- mrandish 1y ago
  > the right process to adjust the resistance of my existing knobs I too have "a thing" about the feel of tactile control elements ranging from the tensioning of knobs and joysticks to the dampening on sliders, the force on my emulation arcade cabinet buttons and, of course, the keyswitches, o-rings and lube on my computer mechanical keyboards. However, I don't really feel a need for software control of the tensioning feel. For example, I have a few different high-end dual-joystick radio control transmitters for RC aircraft. These have fairly pricey hall effect joystick mechanisms and the good ones have a tensioning adjustment for each axis on the bottom. Whether on these RC transmitters, my arcade cabinet or high-end console game controllers I find it's sufficient to simply set the tensioning to my preferences once and I don't feel the need to change it again. So for the EuroKnob, I agree having no tensioning would be pretty awful - as there's little worse than a floppily loose knob wiggling about - but for me a simple friction-based drag adjustment would be fine.
bondarchuk 1y ago
>It's a nice dream, of a synthesizer where any knob can be pulled out and replaced with a patch cable, and any jack can have a knob plugged into it to set it to a fixed value. What's even better, though, is a coupled knob + jack where the knob turns into an attenuator for the input when a cable is plugged in, and works as a standalone knob otherwise. I think this is quite a common design. I believe I've also seen patch cables with built-in attenuators.
- kennywinker 1y ago
  Another common pattern is jack + offset. The most useful is when you have jack + offset + attenuator… but most modules pick one or the other for space reasons.
  - BlandDuck 1y ago
    Totally. Also, an attenuator is easier and cheaper to implement, because it just requires normalizing V+ into the jack plug. An offset requires an adder. My preference is: attenuator < offset < attenuator + offset. I see no benefit of having to remove the knob to get to the jack as proposed in the article.
    - nine_k 1y ago
      The benefit is saving space. Imagine a 10x10 grid of such jack / knob inputs.
  - robotresearcher 1y ago
    The attenuator-inverter is super handy too. A gain knob that goes from -1 to +1 X.
    - wbl 1y ago
      That's a neat trick. Only way I can think of to do it involves two op amp buffers, one inverting one not and take the signal from the wiper.
  - 1y ago
Fredkin 1y ago
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JKCalhoun 1y ago
It's interesting. I haven't been sucked into the Eurorack thing though — do people want not just patch cables all over their mixing desk but knobs as well? Eurorack (and modular synths in general) seem like funny things. Like guitar pedals, I sense there are a lot of enthusiasts that do a lot more tinkering than actually playing them. Watching Rick Beato and guests on YouTube ... seems like a lot of musicians are looking instead for simplicity. Like a few good sounding pedals that, ideally, each have just a knob or two. Maybe the synth-heads are in a whole different headspace though.
- tym0 1y ago
  It's somewhat similar to people enjoying developing their game engine more than their game in my experience. Provably why in attracted to it despite having little musical talent :)
- diggan 1y ago
  > It's interesting. I haven't been sucked into the Eurorack thing though — do people want not just patch cables all over their mixing desk but knobs as well? I don't personally feel the need of wanting more cables all over my current setup, but sometimes I have had the feeling of "Oh if I could just modulate the VCF Cutoff on my Zen Delay with a patch cable from my modular instead of doing it manually" for some of the desktop units I have next to the modular. And on the other side, I've also felt the need of having some of the patch holes replaced by knobs, so I could just twist and turn it to evaluate if I want to modulate it, instead of having to actually setup the patch. I could see something like this knob-idea being very useful for that, basically prototyping patches. > I sense there are a lot of enthusiasts that do a lot more tinkering This is definitely true, large parts of the community is about tinkering more than making music. But the same is true for programming, large parts of the community is not about problem solving, but coding. That's fine, we all have different motivations :) What I found really useful (for myself at least) is to try to connect with people who are artists first, who just happen to be using modular synths, rather than finding people tinkering with modular synths who don't actually produce/perform music. > I haven't been sucked into the Eurorack thing though Good for you :) A friend pulled me into this dark abyss a month ago. Lots of fun, so many distractions, but lots of fun. Helps that Barcelona (where I live) have a lively community around modular synths as well. It is expensive though, and VCVRack doesn't come close to providing the same experience.
dylan604 1y ago
"It's a beautiful dream – a very expensive, but beautiful dream." While that might be true, what is expensive for me is chump change for someone else. However, that is very difficult to grok as there was no prices mentioned anywhere that I could see. Sure, it'll be expensive to me because I have to ask. But I also know that I cannot afford a fully spec'd out MacPro, but at least I can see the numbers.
buescher 1y ago
This is so cool and so clever I'm in awe, really. I'm grinning from ear to ear looking at this and jealous I didn't think of it. But the problem it solves is not quite one that anyone has. What does it offer over a built-in knob with a jack that overrides it beside compactness? A knob that's not designed for feel that you can misplace? There's a miniature case study in thinking about innovation here. This is what the germ of a really neat idea looks like but you have to keep going and that's hard.
- CamperBob2 1y ago
  As he mentions in the video, the whole motivation is compactness. When your panel looks like https://learningmodular.com/the-eurorack-expansion-project/ https://learningmodular.com/the-eurorack-expansion-project/ , every mm^2 matters. I'd be tempted to eliminate the patch cord altogether by using one of those pushbutton pots. Normally it would act like a traditional pot, but if you push it, it would go into a mode where you could choose from a variety of nearby inputs wirelessly. The LEDs next to the pot would need to be an OLED display that indicates the selected input. Some form of extremely lightweight mesh network for control connections would need to exist, something with very low bandwidth and short range but also low latency. After 5 or 10 years' worth of tinkering, it might actually synthesize some sounds.
  - buescher 1y ago
    Right - it solves the compactness problem but introduces new ones. That said, from what I've seen of other people's modular setups, keeping them from growing without bound does not seem to be the highest priority in that world. I'd also have to wonder how well a jack would hold up under regular use as a bushing. It's very common for engineers with little exposure to the connector industry (not my background either, but I read the data sheets and app notes) to underestimate how highly engineered and optimized for their use case even decades-old connector types are. It would be nice to have something like the NKK display pushbuttons in the knob for a rotary encoder/pushbutton. >After 5 or 10 years' worth of tinkering, it might actually synthesize some sounds. Yeah.
spankalee 1y ago
Wouldn't it be more universally compatible to have a powered knob that outputs a adjustable constant control voltage? You'd probably want trim adjustments on it too. Yes, there'd be an extra wire to the power supply module, but that seems fine for a modular.
- diggan 1y ago
  > Yes, there'd be an extra wire to the power supply module, but that seems fine for a modular. Maybe other's modular synths look/work differently than mine, but when all the panels are installed, there is no way to pull a cable from underneath the panels/inside the case to the outside, without drilling new holes through some panel or the sides of the case. So not sure how you'd pull a cable from the power supply to the front side of a panel when it's closed like that. My case is a Intellijel Palette 104HP, maybe other cases expose the power supply to the outside?
- tpm 1y ago
  Yes, but there are already many of these in modular form (usually attenuators normalled to +5V in the absence of input voltage or just fader modules without inputs). This is new :)
arnorhs 1y ago
This looks super neat and probably a fun project to build. > It's a nice dream, of a synthesizer where any knob can be pulled out and replaced with a patch cable, and any jack can have a knob plugged into it to set it to a fixed value. Whether it's actually practical to build a synth like this I'm unsure. It would probably only be worthwhile if you applied it to every single control on the modular, which rules out using other people's modules. You would have to invest heavily into the Eurorack Knob Idea. You couldn't even port other modules that easily, as many of them would expect a real potentiometer, whereas the encoder can only produce a voltage. Coupling it with a voltage-controlled potentiometer would work, but would be even more expensive. Yeah, it's hard to imagine this fitting in nicely to everything since it's defintely more effort and work than just having a knob and a jack for the control of a particular thing. Esp. since most of the time, as a convention, you'll have a knob that controls the value, but when a jack is plugged in, this same knob acts as the attenuator for the signal. I would have appreciated having an image or a pdf of the schematic for the design to understand it properly - i can get it from your github but I don't have kicad installed on this computer. I'm esp. interested in the normalized behavior - ie. when you have a signal plugged in to the jack that is _not_ the potentiometer.. does it get passed through or does it have to go through this chip as well? Having to supply a 3V to this to make it work as well is also an extra requirement of its usefulness in normal eurorack circuits - not a total dealbreaker but that does add extra requirements, and extra components to one's design. Anyways... really cool idea :)
joemi 1y ago
It's an interesting idea (truly a clever way to accomplish this!), but I think it's addressing the symptom, not the problem. The symptom is that some jacks don't have associated knobs. The problem is that either the module designer or the module user is overly obsessed with miniaturization. The designer is at fault if it's a parameter that really should have had a knob with the jack and they avoided including one in order to keep things small. The user is at fault if they're trying to stay so space-constrained that they can't fit a module that outputs an DC voltage set by a knob into their case. There are numerous modules that do this (and often that attenuvert as well) and many of them are fairly small too.
- anigbrowl 1y ago
  The problem is that different people have genuinely different ideas on what kind of modulations are sensible. My go-to example on this is E-mu gear - a company that started out making big modulars in the 70s and went on to dominate the sampler/rompler space for about a decade before going bust during the dot com boom and being absorbed by Creative. the nice thing about E-my synths was that they nearly all had big modulation matrices included, although users were often defeated by the 2-line LCD on their romplers. But one strange omission from the modulation destinations was filter resonance; all their later modules included a huge (arguably excessive) selection of filter types, but for reasons of computational efficiency you could not adjust the resonance while a note was playing. This wasn't too bad from the front panel because most people want to ride the cutoff rather than the Q, but the inability to modulate it inadvertently highlighted some limitations of the filter design. I can see both sides, as I am a 'let me modulate everything' person when choosing gear but at the same time I quite admire 'opinionated' synth designs where flexibility is traded off against maximizing sweet spots. Sometimes it's better to have an instrument with limited sonic range but which responds very consistently within that, so 'you can't get a bad sound out of it'.
jimbokun 1y ago
I liked the video focused on his hands, where his gestures and expressing the rough size and orientation of things added to his verbal description. Not sure if this is a common technique, but works very well for this topic.
- Gracana 1y ago
  This Old Tony (a hobby machinist / welder on youtube) has made all of his videos in that format. It works very well! https://www.youtube.com/c/thisoldtony/videos https://www.youtube.com/c/thisoldtony/videos
moebrowne 1y ago
Anyone know what is being used to render the git repo for this? https://git.mitxela.com/euroknob https://git.mitxela.com/euroknob
- devinvs 1y ago
  looks like it's this: https://git.mitxela.com/web-git-sum https://git.mitxela.com/web-git-sum
butlike 1y ago
Fantastic idea except for the proprietary 3.5" knob. From the video it appears the magnet is required to discern position.
alnwlsn 1y ago
> any jack can have a knob plugged into it to set it to a fixed value. I'm kind of surprised he didn't start with a knob with a tiny accelerometer, mcu and battery in it to produce some sort of output signal into a stock plug depending on how the knob is oriented with respect to gravity. Putting electronics inside the plug is nearly a mitxela trademark. https://mitxela.com/projects/flash_synth https://mitxela.com/projects/flash_synth
- pea 1y ago
  I was wondering this - I'd buy this if I could just plug it into my existing sockets. I'm pretty sure you could get 50-100 hrs with a battery, but I wonder if you could have something that you wind-up like a mechanical watch.
- naikrovek 1y ago
  Probably because pulling on cords can twist them. That’s what I thought when this occurred to me.
- sigy 1y ago
  Profit margins on eurorack are pretty damn low. And you need a lot of knobs and jacks and plugs. Even a hall effect sensor may be out of the sweet spot for cost.
m_kos 1y ago
1. I find Tim's work always so impressive and humbling. Compared to software, hardware projects seem infinitely more complex. 2. Speaking of knobs, I am writing a toy software synth for smartphones. Are there any design guidelines for mobile UI for audio? Knobs are hard to use and sliders take up a lot of space with only a little more precision. I experimented with curved sliders (inverted parabola or sine), but they are confusing since height doesn't really encode anything and the curvature is there only to make the slider longer. I didn't find any design systems focused on audio components.
- ecolonsmak 1y ago
  Knobs shouldn't be hard to use - hold down the knob that needs the adjustment and then drag in either of two directions to set the value. Maybe have a pop-up over the knob that displays the value as it's in use.
  - recursive 1y ago
    Loopy Pro has a cool convention that I haven't seen elsewhere for this. Drag up or down to change the knob value. While doing that, drag left or right to zoom in. That makes the up/down movement more precise.
    - m_kos 1y ago
      I will look into it! Is this for mobile or desktop? I would like to see how they introduce this interaction pattern and what feedback they provide as you interact with the knob.
      - recursive 1y ago
        It's an ios app. IMO it's really good. I own exactly one apple product, and it's an iPad that only runs Loopy Pro. Here's a section from the manual that loosely explains the concept[1]: > Adjust a slider or dial’s value by dragging up and down, or left and right for horizontal sliders. For finer control, move your finger away from the dial. [1]: https://loopypro.com/manual/#sliders-and-dials https://loopypro.com/manual/#sliders-and-dials
atoav 1y ago
As a fellow Eurorack circuit designer and university teacher on thst issue one immidiate issue I can see is one of practicality. Decent potentiometers are maybe a Euro per piece if bought in bulk, they have a start and an end which is nice and for analog gear you have direct control over the parameter, with very clear feedback what is going on — that is the main reason people want physical gear. So add in a LED ring for visual feedback and endstops.. Might be nice for a digital module. But even then I'd wonder if it worth it, because of the high pcb space usage. With potentiometers as attenuators or attenuverters you can fit two pots next to each other in a space of 20mm which neatly aligns with the standard panel widths. Theoretically you could certainly get smaller with thst solution, but the hall effect IC needs to be accounted for as well. With existing pots I can use the space underneath. If your module is just 10mm wide that space is pretty premium..
csours 1y ago
Ok, but why stop here? You've effectively created a rotary potentiometer in one dimension, you could add two more dimensions like an analog thumbstick on a game controller. Do any controllers have a twistable thumbstick? Also, like other commentors have stated - this could be a jack too, so you could have a jack knob analog stick. BUT WHY STOP THERE? You could mount it on a linear pot/slider. BUT WHY STOP THERE?! (help me) You could daisy chain pluggable rotary analog stick jack stacks... ---- The madness has taken him
- tpm 1y ago
  There are several 'joystick' controller modules (Doepfer a-174-4 or Intellijel Planar come to mind) and the Doepfer also produces 3rd signal by twisting the knob.
- mrandish 1y ago
  > Do any controllers have a twistable thumbstick? Yes, several. For example, the main knob on the Komplete Kontrol S-series MIDI controllers (https://www.native-instruments.com/en/products/komplete/keyboards/kontrol-s49-s61-s88/ https://www.native-instruments.com/en/products/komplete/keyb...) combines a rotary encoder with four axis directional input, a push button and an LED indicator ring. I have an S61 and the implementation of the knob is delightfully intuitive, responsive and functional. To be clear, this implementation is not a joystick on a ball base with twistable knob, it's a flush-mounted knob that can be slightly nudged up, down, left or right with a single, satisfying click in each direction. I'd recommend trying it yourself, if only there were still any music stores that put a range of high-end midi controller keyboards out where customers could, you know, touch them. I actually came here to suggest the same idea for the EuroKnob. The four axis directional input is basically a D-Pad module commonly used in game controllers. I find this kind of rotary knob + directional input control to be very effective. However, there's one critical caveat. It's apparently possible to implement this kind of control poorly because I've also seen a couple devices where the implementation is as bad as the S61's is great. It probably just requires a certain degree of engineering finesse to nail a good combination of responsiveness and tactile feedback. > You could mount it on a linear pot/slider. As much as I like and agree with your first thought, I've actually seen the idea of a rotary knob combined with a linear slider - although it's extremely rare. Having touched one myself I can confirm the reason it's rare is that it's not just bad - it's uniquely bad. By which I mean the combination of two controls which each work so well on their own into one combined control, is unexpectedly awful. I was unfortunate enough to try one first-hand (so to speak) at a tiny booth buried in the back of some long-forgotten NAMM show in the days when Cubase was still being demoed on an Atari ST. There was a bespoke mixer from a company I'd never heard of with rotary knobs on their mixer's sliders. I'm pretty sure when I tried to adjust the two parameters at the same time I may have reflexively pulled my hand back and uttered "Ugh!" Usually I'm polite when trying out some novel interface idea but there must be something 'special' about trying to combine two very precise but divergent proportional motions on two different arm joins (wrist & elbow) at the same time that's deeply unnatural. It felt so weirdly wrong that I suspect some human factors kinesiologist has probably written an award-winning paper about how humans evolved to never, ever do this. But hey, one out of two ideas is still a great day! :-)
dimal 1y ago
I like it, but the best modules already have knobs and jacks for everything. When you have CV going into the jack, the knob acts as an attenuator or attenuverter. This means that the modules are generally larger. Make Noise generally does this and their modules are consistently bigger than everyone else, and they're also some of the most popular. Look at Maths. It's a slope generator and a mixer. It's fucking huge. But everyone has it because it's patch programmable. The problem in Eurorack is instead of making things patch programmable, they try to fit in a ton of functionality into a small space, so you have a lot of modules that have multiple modes where buttons and knobs all have different meanings depending on what "page" you're on. Fuck that. Almost every time I try a module like that, I end up selling it. He's right about the interface being the point of Eurorack. Plugging things into other things is the whole point. When I have a module that has hidden state, I forget what state it's in or what the knobs mean. I end up avoiding those modules. With cables and knobs, I can see the state of the whole system. I need good cable management to make sure it's not spaghetti, but I already do that in code already, and it's not that different.
smj-edison 1y ago
Tangential idea, but I've wondered if it would be possible to make synthesizers a lot cheaper by only having a couple rotary encoders. You could have hundreds of parameters on the panel, but each parameter would just be a neopixel LED and button. You could link the rotary encoder with a parameter by pressing it and the parameters' button at the same time. Certainly not as nice as a dedicated knob for each, but you'd also get an interface that is ~$40 instead of ~$600...
- mdpye 1y ago
  There are loads of systems where every button and encoder has many functions, with modal or paged interfaces. But I'm trying to stick to a model of no hidden or ephemeral state with my modular, just for fun, I guess. Mostly analogue, so no non-volatile memory to store settings, the positions of the patches and knobs set everything, and the test is that if I power it down and back up it must come back doing what it was doing when the power went out (very long cycle lfos notwithstanding!) When a laptop can simulate anything, the physicality of the interface is most of the attraction, so might as well go all the way...
  - smj-edison 1y ago
    For sure! The interface is the most important part these days when practically everything can be emulated. In my design, I wouldn't say the state is hidden though—that's the point of having an indicator light with every parameter. The LED becomes the state visualization. So, write-wise, yes, it's overloaded, but read-wise it's not. I'm just now realizing I didn't explain that well in the OP, lol. And really this is more of a budget-friendly approach, rather than a user-friendly approach. I'm trying to meet those half way...
- sigy 1y ago
  The physical interface is an intrinsic part of the design of any eurorack module, including artistic elements. If you actually use these, then you quickly tire of menu diving for simple options, and only modules that do very particular things make it worth the bother. For everything else, the layout must be accessible, memorable, understandable, and not too crowded. And it helps if the visual of the thing conjures up memories of how it sounds or what it does.
fitsumbelay 1y ago
E W A E M O S
UltraSane 1y ago
Eurorack is very cool and I totally understand the appeal of having physical devices to interact with but one thing I never understood is how you can recreate a specific configuration you liked later. Do you manually document every connection? Or just take pictures?
- anigbrowl 1y ago
  Neither, you just tell people about how great it was. Ideally, you don't record it either so that you can filter out the less imaginative people from your social circle. If challenged, you explain that you've moved on to a more abstract aesthetic, a musical plane which requires greater levels of commitment to attain.
  - JodieBenitez 1y ago
    Nailed it.
- skinpop 1y ago
  Once it's gone it's gone. That's part of what I like about analogue modular synthesizers. It's a liberating approach to doing music if you embrace it for what it is.
  - UltraSane 1y ago
    So it is more of a toy than an actual tool.
aylmao 1y ago
Very cool idea! It reminds me of how software works— you usually drag an LFO to the knob to modulate a parameter. A few people have pointed out that the knob can act as an attenuator when it's being modulated via a jack, but sometimes the goal is space. I can also imagine a version of this that uses the same technique, but where the knob has an audio jack on it. You wouldn't need to unplug it to connect the incoming cable, and you could use the still-connected knob as an attenuator if you wanted to. This would get you the best of all worlds— maximum space, an intuitive interface, and attenuators if you so choose to have them.
frainfreeze 1y ago
Be sure to check their other projects! Stylophone business card is one of my favs: https://mitxela.com/projects/stylocard https://mitxela.com/projects/stylocard
adrianmonk 1y ago
Apologies if I'm missing something obvious, but why not just stick a potentiometer on the same axis behind the 3.5mm TS jack? Many 3.5mm jacks are open on the back, so you can give the knob a long shaft (longer than 3.5mm obviously), and that shaft can mate with the potentiometer. Alternatively, Eurorack uses TS jacks as connectors for control voltage inputs, right? If you build a module with a TRS jack instead, you have an extra pin (R) that you can connect a removable potentiometer + knob to. And you can still plug in regular TS cables. (Note: the article uses "TRS" loosely when it means "TS". I mean them literally.)
- raphman 1y ago
  Yes, this sounds like a simpler solution - the major drawback/advantage would be that you'd need to insert the knob in just the right orientation so that the shaft end fits into the potentiometer's slot. Might be a bit fiddly. On the other hand, the poti would keep its state even when the knob is removed, and you wouldn't accidentally change the value when inserting the knob. Just to nitpick the nitpicker: the knob's shaft needs to be longer than 15 mm, right? "3.5 mm" is the diameter, not the length of a small T(R)S jack.
  - adrianmonk 1y ago
    Oops, yes, 3.5mm is the diameter. I was sleepy when I wrote that, and I knew it didn't seem right. Good point about the orientation when inserting. I was thinking something like hex or torx or friction fit that would allow you to insert it without thinking about the orientation. But then that causes another problem: any visual markings on the knob aren't guaranteed to be in the right position. I'm not sure if there's a good way get the best of both worlds on that.
    - raphman 1y ago
      Something like this might work. When pushing the knob in, a spiral inside it rotates around the tongue that is attached to the potentiometer (or vice versa). Once it is fully pushed in, the groove in the spiral rests against the tongue, allowing the knob to turn the potentiometer. Would probably need a lot of fine-tuning to get all forces exactly right. https://winterwind.org/_media/pasted/20250426-220417.png https://winterwind.org/_media/pasted/20250426-220417.png
gitroom 1y ago
been messing with gear for years and honestly the obsession with cramming everything into tiny boxes always cracks me up, but the idea of knobs you can move around is actually kinda sick. you ever feel like stuff gets too complicated and takes away from just having fun making sound?
sokoloff 1y ago
Why not route out the FR4 under the TRS jack and sense the magnet from parts mounted on the other side on a single PCB?
schobi 1y ago
I love the out-of-box thinking and clean execution by mitxela. But why not make it the other way round? Downsides: you need enough magnetic knobs and store them when not in use. If this becomes popular, will all knobs be compatible? What if you loose some? If you buy a used module? This idea somehow creates a new set of problems. Idea: Knob with a plug! The outer dimension of a knob is limited by how easily you can grab it. Even if used as a socket, you need the sideways spacing anyway. But the knob face is not used. Why not have the socket in the center of the knob? How to build this? You would need a hollow knob riding on a bearing surface around the socket. I vaguely remember magnetic position decoders that work off-axis? Or maybe have multiple magnets in the rim of the knob, in an orientation that creates a uniform magnetic field in the center? The current prototype would even be suitable for trying. Benefits: no extra removable components. Knob and socket can be used at the same time. Can you still reach around a plugged-in cable? Is this even useful?
deleted 1y ago
[deleted]

Eurorack Knob Idea

322 points by po 1y ago

d--b 1y ago

It's like real life functional programming. Can't wait for the y-combinator module.

itomato 1y ago

I’m just waiting for the Eurorack Boombox revolution to hit.

diggan 1y ago

Interesting idea for sure, but how is the feel of actually turning the knob? Seems to offer short to no resistance, which would make fast but precise movements pretty hard, something that is important for things like performances. What would be a huge bonus point (but maybe unrealistic? I don't quite understand how the current implementation actually works) would be software-configurable resistance (physical, not electrical). I've spent a lot of time for my DIY modules to find the right knobs, or the right process to adjust the resistance of my existing knobs, being able to control that digitally could introduce a whole new level of fun.

scottapotamas 1y ago
You might enjoy https://github.com/scottbez1/smartknob https://github.com/scottbez1/smartknob The complexity of this approach (ignoring the display and flair) unfortunately means you won’t see this used too often due to cost.
- diggan 1y ago
  That's so cool on so many levels, and I really enjoyed that indeed, now I have to fight the urge to try to build it myself, good thing it's weekend. However, it does seem to miss the single most useful feature (for me) which is the resistance part. I understand there is a DC motor controlling the snap points and whatnot, but what I'd like is constant resistance I guess, to a configurable level, rather than snapping to specific points and such. I don't think it would be possible to hack on top of the already made hardware, but didn't seem like it was already done in the software side of things, although I did skim through things so maybe I missed it.
  - pakue 1y ago
    Should be doable to add that. The BLDC needs to add a proportional (or any other function) force against the rotation direction until it reaches 0.
    - diggan 1y ago
      Sounds reasonable, wonder how that would actually feel in real life? As far as I understand, this would pass through digital parts, adding a little bit of (maybe noticeable) latency, but I wonder if the latency gets high enough for it to be a bit jarring that the resistance is dynamically changing as you apply torque.
      - scottapotamas 1y ago
        This is all fairly normal in robotics, under a subset of (slightly overloaded naming sorry) “impedance control”
      - camtarn 1y ago
        In practice, when latency is small enough (on the ~1ms level, which is trivial to achieve using even pretty cheap parts) it's imperceptible. I sometimes develop control loops for prototype systems which use a motor to emulate a combination of spring + friction damper, and even though I know that my code only runs every 1ms, it's really remarkable how much it feels like a real continuous analogue system. Another good example is power steering, which uses a motor to remove resistance instead of add it. If I understand it correctly, it senses you applying torque to the steering column and adds proportional amounts of boost - but because it happens so fast, it just feels like the steering is magically lighter.
- adolph 1y ago
  A differently complex and smaller approach might be to combine the knob with with an axial flux PCB-BLDC, like what Carl Bugeja made [0, 1]. It might be suited to get haptics in something as small as the article's knob, although to get an in-built display you'd have to use one of those displays that fit in lego bricks [2, 3] with a slip-ring. 0. https://microbots.io/products/motorcell https://microbots.io/products/motorcell 1. https://www.youtube.com/watch?v=CVszJMlvZcA https://www.youtube.com/watch?v=CVszJMlvZcA 2. https://github.com/AncientJames/uGrey https://github.com/AncientJames/uGrey 3. https://www.youtube.com/watch?v=0pUV_3qeHog https://www.youtube.com/watch?v=0pUV_3qeHog
  - diggan 1y ago
    Many thanks for the links/references. I don't really care about the display itself (probably prefer without it actually), but never saw those other links before, interesting stuff.
- weinzierl 1y ago
  My dream is a piano keyboard with entirely software controlled mechanical key response. Every key individually mounted on a servostepper. As a bonus it could be used as a fake player piano. Or for practice you could make the wrong keys hard to press. Endless possibilities.
  - Q6T46nT668w6i3m 1y ago
    Great idea and I’m shocked this doesn’t exist.
    - robotresearcher 1y ago
      It would likely be very, very expensive. A compromise that is affordable and does exist is programmable response curves to key velocity and aftertouch pressure. It can make sense to have different curves for eg. piano vs harpsichord even if you can’t change the mechanical key impedance. I haven’t seen it in the wild, but using this you could make the wrong notes quieter/louder or even play a different sound. But I think we all know when we play a wrong note, so the utility might be small.
      - mrandish 1y ago
        > key velocity and aftertouch pressure. Just a tangential note to say whenever I see these terms in discussion of MIDI keyboards it reminds me how disappointed I am the vast majority of MIDI controller (and multi-thousand dollar flagship synth) keyboards still don't fully support per note velocity or polyphonic aftertouch. It's only been 40 years kids... (sigh).
        otabdeveloper4 1y ago
        Not really needed. A synthesizer is not a piano, it's essentially a wind instrument.
        lsaferite 1y ago
- hinkley 1y ago
  This is what cars need. Only make the entire dial depressable instead of the embedded screen. Use different haptics for each setting so you can feel which setting you’re changing.
mrandish 1y ago
> the right process to adjust the resistance of my existing knobs I too have "a thing" about the feel of tactile control elements ranging from the tensioning of knobs and joysticks to the dampening on sliders, the force on my emulation arcade cabinet buttons and, of course, the keyswitches, o-rings and lube on my computer mechanical keyboards. However, I don't really feel a need for software control of the tensioning feel. For example, I have a few different high-end dual-joystick radio control transmitters for RC aircraft. These have fairly pricey hall effect joystick mechanisms and the good ones have a tensioning adjustment for each axis on the bottom. Whether on these RC transmitters, my arcade cabinet or high-end console game controllers I find it's sufficient to simply set the tensioning to my preferences once and I don't feel the need to change it again. So for the EuroKnob, I agree having no tensioning would be pretty awful - as there's little worse than a floppily loose knob wiggling about - but for me a simple friction-based drag adjustment would be fine.

bondarchuk 1y ago

>It's a nice dream, of a synthesizer where any knob can be pulled out and replaced with a patch cable, and any jack can have a knob plugged into it to set it to a fixed value. What's even better, though, is a coupled knob + jack where the knob turns into an attenuator for the input when a cable is plugged in, and works as a standalone knob otherwise. I think this is quite a common design. I believe I've also seen patch cables with built-in attenuators.

kennywinker 1y ago
Another common pattern is jack + offset. The most useful is when you have jack + offset + attenuator… but most modules pick one or the other for space reasons.
- BlandDuck 1y ago
  Totally. Also, an attenuator is easier and cheaper to implement, because it just requires normalizing V+ into the jack plug. An offset requires an adder. My preference is: attenuator < offset < attenuator + offset. I see no benefit of having to remove the knob to get to the jack as proposed in the article.
  - nine_k 1y ago
    The benefit is saving space. Imagine a 10x10 grid of such jack / knob inputs.
- robotresearcher 1y ago
  The attenuator-inverter is super handy too. A gain knob that goes from -1 to +1 X.
  - wbl 1y ago
    That's a neat trick. Only way I can think of to do it involves two op amp buffers, one inverting one not and take the signal from the wiper.
- 1y ago

Fredkin 1y ago

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JKCalhoun 1y ago

It's interesting. I haven't been sucked into the Eurorack thing though — do people want not just patch cables all over their mixing desk but knobs as well? Eurorack (and modular synths in general) seem like funny things. Like guitar pedals, I sense there are a lot of enthusiasts that do a lot more tinkering than actually playing them. Watching Rick Beato and guests on YouTube ... seems like a lot of musicians are looking instead for simplicity. Like a few good sounding pedals that, ideally, each have just a knob or two. Maybe the synth-heads are in a whole different headspace though.

tym0 1y ago
It's somewhat similar to people enjoying developing their game engine more than their game in my experience. Provably why in attracted to it despite having little musical talent :)
diggan 1y ago
> It's interesting. I haven't been sucked into the Eurorack thing though — do people want not just patch cables all over their mixing desk but knobs as well? I don't personally feel the need of wanting more cables all over my current setup, but sometimes I have had the feeling of "Oh if I could just modulate the VCF Cutoff on my Zen Delay with a patch cable from my modular instead of doing it manually" for some of the desktop units I have next to the modular. And on the other side, I've also felt the need of having some of the patch holes replaced by knobs, so I could just twist and turn it to evaluate if I want to modulate it, instead of having to actually setup the patch. I could see something like this knob-idea being very useful for that, basically prototyping patches. > I sense there are a lot of enthusiasts that do a lot more tinkering This is definitely true, large parts of the community is about tinkering more than making music. But the same is true for programming, large parts of the community is not about problem solving, but coding. That's fine, we all have different motivations :) What I found really useful (for myself at least) is to try to connect with people who are artists first, who just happen to be using modular synths, rather than finding people tinkering with modular synths who don't actually produce/perform music. > I haven't been sucked into the Eurorack thing though Good for you :) A friend pulled me into this dark abyss a month ago. Lots of fun, so many distractions, but lots of fun. Helps that Barcelona (where I live) have a lively community around modular synths as well. It is expensive though, and VCVRack doesn't come close to providing the same experience.

dylan604 1y ago

"It's a beautiful dream – a very expensive, but beautiful dream." While that might be true, what is expensive for me is chump change for someone else. However, that is very difficult to grok as there was no prices mentioned anywhere that I could see. Sure, it'll be expensive to me because I have to ask. But I also know that I cannot afford a fully spec'd out MacPro, but at least I can see the numbers.

buescher 1y ago

This is so cool and so clever I'm in awe, really. I'm grinning from ear to ear looking at this and jealous I didn't think of it. But the problem it solves is not quite one that anyone has. What does it offer over a built-in knob with a jack that overrides it beside compactness? A knob that's not designed for feel that you can misplace? There's a miniature case study in thinking about innovation here. This is what the germ of a really neat idea looks like but you have to keep going and that's hard.

CamperBob2 1y ago
As he mentions in the video, the whole motivation is compactness. When your panel looks like https://learningmodular.com/the-eurorack-expansion-project/ https://learningmodular.com/the-eurorack-expansion-project/ , every mm^2 matters. I'd be tempted to eliminate the patch cord altogether by using one of those pushbutton pots. Normally it would act like a traditional pot, but if you push it, it would go into a mode where you could choose from a variety of nearby inputs wirelessly. The LEDs next to the pot would need to be an OLED display that indicates the selected input. Some form of extremely lightweight mesh network for control connections would need to exist, something with very low bandwidth and short range but also low latency. After 5 or 10 years' worth of tinkering, it might actually synthesize some sounds.
- buescher 1y ago
  Right - it solves the compactness problem but introduces new ones. That said, from what I've seen of other people's modular setups, keeping them from growing without bound does not seem to be the highest priority in that world. I'd also have to wonder how well a jack would hold up under regular use as a bushing. It's very common for engineers with little exposure to the connector industry (not my background either, but I read the data sheets and app notes) to underestimate how highly engineered and optimized for their use case even decades-old connector types are. It would be nice to have something like the NKK display pushbuttons in the knob for a rotary encoder/pushbutton. >After 5 or 10 years' worth of tinkering, it might actually synthesize some sounds. Yeah.

spankalee 1y ago

Wouldn't it be more universally compatible to have a powered knob that outputs a adjustable constant control voltage? You'd probably want trim adjustments on it too. Yes, there'd be an extra wire to the power supply module, but that seems fine for a modular.

diggan 1y ago
> Yes, there'd be an extra wire to the power supply module, but that seems fine for a modular. Maybe other's modular synths look/work differently than mine, but when all the panels are installed, there is no way to pull a cable from underneath the panels/inside the case to the outside, without drilling new holes through some panel or the sides of the case. So not sure how you'd pull a cable from the power supply to the front side of a panel when it's closed like that. My case is a Intellijel Palette 104HP, maybe other cases expose the power supply to the outside?
tpm 1y ago
Yes, but there are already many of these in modular form (usually attenuators normalled to +5V in the absence of input voltage or just fader modules without inputs). This is new :)

arnorhs 1y ago

This looks super neat and probably a fun project to build. > It's a nice dream, of a synthesizer where any knob can be pulled out and replaced with a patch cable, and any jack can have a knob plugged into it to set it to a fixed value. Whether it's actually practical to build a synth like this I'm unsure. It would probably only be worthwhile if you applied it to every single control on the modular, which rules out using other people's modules. You would have to invest heavily into the Eurorack Knob Idea. You couldn't even port other modules that easily, as many of them would expect a real potentiometer, whereas the encoder can only produce a voltage. Coupling it with a voltage-controlled potentiometer would work, but would be even more expensive. Yeah, it's hard to imagine this fitting in nicely to everything since it's defintely more effort and work than just having a knob and a jack for the control of a particular thing. Esp. since most of the time, as a convention, you'll have a knob that controls the value, but when a jack is plugged in, this same knob acts as the attenuator for the signal. I would have appreciated having an image or a pdf of the schematic for the design to understand it properly - i can get it from your github but I don't have kicad installed on this computer. I'm esp. interested in the normalized behavior - ie. when you have a signal plugged in to the jack that is _not_ the potentiometer.. does it get passed through or does it have to go through this chip as well? Having to supply a 3V to this to make it work as well is also an extra requirement of its usefulness in normal eurorack circuits - not a total dealbreaker but that does add extra requirements, and extra components to one's design. Anyways... really cool idea :)

joemi 1y ago

It's an interesting idea (truly a clever way to accomplish this!), but I think it's addressing the symptom, not the problem. The symptom is that some jacks don't have associated knobs. The problem is that either the module designer or the module user is overly obsessed with miniaturization. The designer is at fault if it's a parameter that really should have had a knob with the jack and they avoided including one in order to keep things small. The user is at fault if they're trying to stay so space-constrained that they can't fit a module that outputs an DC voltage set by a knob into their case. There are numerous modules that do this (and often that attenuvert as well) and many of them are fairly small too.

anigbrowl 1y ago
The problem is that different people have genuinely different ideas on what kind of modulations are sensible. My go-to example on this is E-mu gear - a company that started out making big modulars in the 70s and went on to dominate the sampler/rompler space for about a decade before going bust during the dot com boom and being absorbed by Creative. the nice thing about E-my synths was that they nearly all had big modulation matrices included, although users were often defeated by the 2-line LCD on their romplers. But one strange omission from the modulation destinations was filter resonance; all their later modules included a huge (arguably excessive) selection of filter types, but for reasons of computational efficiency you could not adjust the resonance while a note was playing. This wasn't too bad from the front panel because most people want to ride the cutoff rather than the Q, but the inability to modulate it inadvertently highlighted some limitations of the filter design. I can see both sides, as I am a 'let me modulate everything' person when choosing gear but at the same time I quite admire 'opinionated' synth designs where flexibility is traded off against maximizing sweet spots. Sometimes it's better to have an instrument with limited sonic range but which responds very consistently within that, so 'you can't get a bad sound out of it'.

jimbokun 1y ago

I liked the video focused on his hands, where his gestures and expressing the rough size and orientation of things added to his verbal description. Not sure if this is a common technique, but works very well for this topic.

Gracana 1y ago
This Old Tony (a hobby machinist / welder on youtube) has made all of his videos in that format. It works very well! https://www.youtube.com/c/thisoldtony/videos https://www.youtube.com/c/thisoldtony/videos

moebrowne 1y ago

Anyone know what is being used to render the git repo for this? https://git.mitxela.com/euroknob https://git.mitxela.com/euroknob

devinvs 1y ago
looks like it's this: https://git.mitxela.com/web-git-sum https://git.mitxela.com/web-git-sum

butlike 1y ago

Fantastic idea except for the proprietary 3.5" knob. From the video it appears the magnet is required to discern position.

alnwlsn 1y ago

> any jack can have a knob plugged into it to set it to a fixed value. I'm kind of surprised he didn't start with a knob with a tiny accelerometer, mcu and battery in it to produce some sort of output signal into a stock plug depending on how the knob is oriented with respect to gravity. Putting electronics inside the plug is nearly a mitxela trademark. https://mitxela.com/projects/flash_synth https://mitxela.com/projects/flash_synth

pea 1y ago
I was wondering this - I'd buy this if I could just plug it into my existing sockets. I'm pretty sure you could get 50-100 hrs with a battery, but I wonder if you could have something that you wind-up like a mechanical watch.
naikrovek 1y ago
Probably because pulling on cords can twist them. That’s what I thought when this occurred to me.
sigy 1y ago
Profit margins on eurorack are pretty damn low. And you need a lot of knobs and jacks and plugs. Even a hall effect sensor may be out of the sweet spot for cost.

m_kos 1y ago

1. I find Tim's work always so impressive and humbling. Compared to software, hardware projects seem infinitely more complex. 2. Speaking of knobs, I am writing a toy software synth for smartphones. Are there any design guidelines for mobile UI for audio? Knobs are hard to use and sliders take up a lot of space with only a little more precision. I experimented with curved sliders (inverted parabola or sine), but they are confusing since height doesn't really encode anything and the curvature is there only to make the slider longer. I didn't find any design systems focused on audio components.

ecolonsmak 1y ago
Knobs shouldn't be hard to use - hold down the knob that needs the adjustment and then drag in either of two directions to set the value. Maybe have a pop-up over the knob that displays the value as it's in use.
- recursive 1y ago
  Loopy Pro has a cool convention that I haven't seen elsewhere for this. Drag up or down to change the knob value. While doing that, drag left or right to zoom in. That makes the up/down movement more precise.
  - m_kos 1y ago
    I will look into it! Is this for mobile or desktop? I would like to see how they introduce this interaction pattern and what feedback they provide as you interact with the knob.
    - recursive 1y ago
      It's an ios app. IMO it's really good. I own exactly one apple product, and it's an iPad that only runs Loopy Pro. Here's a section from the manual that loosely explains the concept[1]: > Adjust a slider or dial’s value by dragging up and down, or left and right for horizontal sliders. For finer control, move your finger away from the dial. [1]: https://loopypro.com/manual/#sliders-and-dials https://loopypro.com/manual/#sliders-and-dials

atoav 1y ago

As a fellow Eurorack circuit designer and university teacher on thst issue one immidiate issue I can see is one of practicality. Decent potentiometers are maybe a Euro per piece if bought in bulk, they have a start and an end which is nice and for analog gear you have direct control over the parameter, with very clear feedback what is going on — that is the main reason people want physical gear. So add in a LED ring for visual feedback and endstops.. Might be nice for a digital module. But even then I'd wonder if it worth it, because of the high pcb space usage. With potentiometers as attenuators or attenuverters you can fit two pots next to each other in a space of 20mm which neatly aligns with the standard panel widths. Theoretically you could certainly get smaller with thst solution, but the hall effect IC needs to be accounted for as well. With existing pots I can use the space underneath. If your module is just 10mm wide that space is pretty premium..

csours 1y ago

Ok, but why stop here? You've effectively created a rotary potentiometer in one dimension, you could add two more dimensions like an analog thumbstick on a game controller. Do any controllers have a twistable thumbstick? Also, like other commentors have stated - this could be a jack too, so you could have a jack knob analog stick. BUT WHY STOP THERE? You could mount it on a linear pot/slider. BUT WHY STOP THERE?! (help me) You could daisy chain pluggable rotary analog stick jack stacks... ---- The madness has taken him

tpm 1y ago
There are several 'joystick' controller modules (Doepfer a-174-4 or Intellijel Planar come to mind) and the Doepfer also produces 3rd signal by twisting the knob.
mrandish 1y ago
> Do any controllers have a twistable thumbstick? Yes, several. For example, the main knob on the Komplete Kontrol S-series MIDI controllers (https://www.native-instruments.com/en/products/komplete/keyboards/kontrol-s49-s61-s88/ https://www.native-instruments.com/en/products/komplete/keyb...) combines a rotary encoder with four axis directional input, a push button and an LED indicator ring. I have an S61 and the implementation of the knob is delightfully intuitive, responsive and functional. To be clear, this implementation is not a joystick on a ball base with twistable knob, it's a flush-mounted knob that can be slightly nudged up, down, left or right with a single, satisfying click in each direction. I'd recommend trying it yourself, if only there were still any music stores that put a range of high-end midi controller keyboards out where customers could, you know, touch them. I actually came here to suggest the same idea for the EuroKnob. The four axis directional input is basically a D-Pad module commonly used in game controllers. I find this kind of rotary knob + directional input control to be very effective. However, there's one critical caveat. It's apparently possible to implement this kind of control poorly because I've also seen a couple devices where the implementation is as bad as the S61's is great. It probably just requires a certain degree of engineering finesse to nail a good combination of responsiveness and tactile feedback. > You could mount it on a linear pot/slider. As much as I like and agree with your first thought, I've actually seen the idea of a rotary knob combined with a linear slider - although it's extremely rare. Having touched one myself I can confirm the reason it's rare is that it's not just bad - it's uniquely bad. By which I mean the combination of two controls which each work so well on their own into one combined control, is unexpectedly awful. I was unfortunate enough to try one first-hand (so to speak) at a tiny booth buried in the back of some long-forgotten NAMM show in the days when Cubase was still being demoed on an Atari ST. There was a bespoke mixer from a company I'd never heard of with rotary knobs on their mixer's sliders. I'm pretty sure when I tried to adjust the two parameters at the same time I may have reflexively pulled my hand back and uttered "Ugh!" Usually I'm polite when trying out some novel interface idea but there must be something 'special' about trying to combine two very precise but divergent proportional motions on two different arm joins (wrist & elbow) at the same time that's deeply unnatural. It felt so weirdly wrong that I suspect some human factors kinesiologist has probably written an award-winning paper about how humans evolved to never, ever do this. But hey, one out of two ideas is still a great day! :-)

dimal 1y ago

I like it, but the best modules already have knobs and jacks for everything. When you have CV going into the jack, the knob acts as an attenuator or attenuverter. This means that the modules are generally larger. Make Noise generally does this and their modules are consistently bigger than everyone else, and they're also some of the most popular. Look at Maths. It's a slope generator and a mixer. It's fucking huge. But everyone has it because it's patch programmable. The problem in Eurorack is instead of making things patch programmable, they try to fit in a ton of functionality into a small space, so you have a lot of modules that have multiple modes where buttons and knobs all have different meanings depending on what "page" you're on. Fuck that. Almost every time I try a module like that, I end up selling it. He's right about the interface being the point of Eurorack. Plugging things into other things is the whole point. When I have a module that has hidden state, I forget what state it's in or what the knobs mean. I end up avoiding those modules. With cables and knobs, I can see the state of the whole system. I need good cable management to make sure it's not spaghetti, but I already do that in code already, and it's not that different.

smj-edison 1y ago

Tangential idea, but I've wondered if it would be possible to make synthesizers a lot cheaper by only having a couple rotary encoders. You could have hundreds of parameters on the panel, but each parameter would just be a neopixel LED and button. You could link the rotary encoder with a parameter by pressing it and the parameters' button at the same time. Certainly not as nice as a dedicated knob for each, but you'd also get an interface that is ~$40 instead of ~$600...

mdpye 1y ago
There are loads of systems where every button and encoder has many functions, with modal or paged interfaces. But I'm trying to stick to a model of no hidden or ephemeral state with my modular, just for fun, I guess. Mostly analogue, so no non-volatile memory to store settings, the positions of the patches and knobs set everything, and the test is that if I power it down and back up it must come back doing what it was doing when the power went out (very long cycle lfos notwithstanding!) When a laptop can simulate anything, the physicality of the interface is most of the attraction, so might as well go all the way...
- smj-edison 1y ago
  For sure! The interface is the most important part these days when practically everything can be emulated. In my design, I wouldn't say the state is hidden though—that's the point of having an indicator light with every parameter. The LED becomes the state visualization. So, write-wise, yes, it's overloaded, but read-wise it's not. I'm just now realizing I didn't explain that well in the OP, lol. And really this is more of a budget-friendly approach, rather than a user-friendly approach. I'm trying to meet those half way...
sigy 1y ago
The physical interface is an intrinsic part of the design of any eurorack module, including artistic elements. If you actually use these, then you quickly tire of menu diving for simple options, and only modules that do very particular things make it worth the bother. For everything else, the layout must be accessible, memorable, understandable, and not too crowded. And it helps if the visual of the thing conjures up memories of how it sounds or what it does.

fitsumbelay 1y ago

E W A E M O S

UltraSane 1y ago

Eurorack is very cool and I totally understand the appeal of having physical devices to interact with but one thing I never understood is how you can recreate a specific configuration you liked later. Do you manually document every connection? Or just take pictures?

anigbrowl 1y ago
Neither, you just tell people about how great it was. Ideally, you don't record it either so that you can filter out the less imaginative people from your social circle. If challenged, you explain that you've moved on to a more abstract aesthetic, a musical plane which requires greater levels of commitment to attain.
- JodieBenitez 1y ago
  Nailed it.
skinpop 1y ago
Once it's gone it's gone. That's part of what I like about analogue modular synthesizers. It's a liberating approach to doing music if you embrace it for what it is.
- UltraSane 1y ago
  So it is more of a toy than an actual tool.

aylmao 1y ago

Very cool idea! It reminds me of how software works— you usually drag an LFO to the knob to modulate a parameter. A few people have pointed out that the knob can act as an attenuator when it's being modulated via a jack, but sometimes the goal is space. I can also imagine a version of this that uses the same technique, but where the knob has an audio jack on it. You wouldn't need to unplug it to connect the incoming cable, and you could use the still-connected knob as an attenuator if you wanted to. This would get you the best of all worlds— maximum space, an intuitive interface, and attenuators if you so choose to have them.

frainfreeze 1y ago

Be sure to check their other projects! Stylophone business card is one of my favs: https://mitxela.com/projects/stylocard https://mitxela.com/projects/stylocard

adrianmonk 1y ago

Apologies if I'm missing something obvious, but why not just stick a potentiometer on the same axis behind the 3.5mm TS jack? Many 3.5mm jacks are open on the back, so you can give the knob a long shaft (longer than 3.5mm obviously), and that shaft can mate with the potentiometer. Alternatively, Eurorack uses TS jacks as connectors for control voltage inputs, right? If you build a module with a TRS jack instead, you have an extra pin (R) that you can connect a removable potentiometer + knob to. And you can still plug in regular TS cables. (Note: the article uses "TRS" loosely when it means "TS". I mean them literally.)

raphman 1y ago
Yes, this sounds like a simpler solution - the major drawback/advantage would be that you'd need to insert the knob in just the right orientation so that the shaft end fits into the potentiometer's slot. Might be a bit fiddly. On the other hand, the poti would keep its state even when the knob is removed, and you wouldn't accidentally change the value when inserting the knob. Just to nitpick the nitpicker: the knob's shaft needs to be longer than 15 mm, right? "3.5 mm" is the diameter, not the length of a small T(R)S jack.
- adrianmonk 1y ago
  Oops, yes, 3.5mm is the diameter. I was sleepy when I wrote that, and I knew it didn't seem right. Good point about the orientation when inserting. I was thinking something like hex or torx or friction fit that would allow you to insert it without thinking about the orientation. But then that causes another problem: any visual markings on the knob aren't guaranteed to be in the right position. I'm not sure if there's a good way get the best of both worlds on that.
  - raphman 1y ago
    Something like this might work. When pushing the knob in, a spiral inside it rotates around the tongue that is attached to the potentiometer (or vice versa). Once it is fully pushed in, the groove in the spiral rests against the tongue, allowing the knob to turn the potentiometer. Would probably need a lot of fine-tuning to get all forces exactly right. https://winterwind.org/_media/pasted/20250426-220417.png https://winterwind.org/_media/pasted/20250426-220417.png

gitroom 1y ago

been messing with gear for years and honestly the obsession with cramming everything into tiny boxes always cracks me up, but the idea of knobs you can move around is actually kinda sick. you ever feel like stuff gets too complicated and takes away from just having fun making sound?

sokoloff 1y ago

Why not route out the FR4 under the TRS jack and sense the magnet from parts mounted on the other side on a single PCB?

schobi 1y ago

I love the out-of-box thinking and clean execution by mitxela. But why not make it the other way round? Downsides: you need enough magnetic knobs and store them when not in use. If this becomes popular, will all knobs be compatible? What if you loose some? If you buy a used module? This idea somehow creates a new set of problems. Idea: Knob with a plug! The outer dimension of a knob is limited by how easily you can grab it. Even if used as a socket, you need the sideways spacing anyway. But the knob face is not used. Why not have the socket in the center of the knob? How to build this? You would need a hollow knob riding on a bearing surface around the socket. I vaguely remember magnetic position decoders that work off-axis? Or maybe have multiple magnets in the rim of the knob, in an orientation that creates a uniform magnetic field in the center? The current prototype would even be suitable for trying. Benefits: no extra removable components. Knob and socket can be used at the same time. Can you still reach around a plugged-in cable? Is this even useful?

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