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Eurorack Knob Idea

mitxela.com

21–30 of 123 posts

Re: Eurorack Knob Idea

#21

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.

> 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?

Re: Eurorack Knob Idea

#22
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 :)

Re: Eurorack Knob Idea

#23
post #17

Earlier quoted context omitted.

You might enjoy 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.

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 1. https://www.youtube.com/watch…

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.

Re: Eurorack Knob Idea

#24
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.

Re: Eurorack Knob Idea

#25

Earlier quoted context omitted.

You might enjoy 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.

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.

> Or for practice you could make the wrong keys hard to press.

This seems like a pretty cool idea

Re: Eurorack Knob Idea

#26
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.

Re: Eurorack Knob Idea

#28

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 loo…

> Like a few good sounding pedals that, ideally, each have just a knob or two.

It makes for a nice narrative but I haven't found it holds much water; musicians are all over the place on this spectrum. You'll find both extremes very well represented, and a good chunk of people who compartmentalize their "dayjob" music and tinkering. I've found a lot of successful musicians love to tinker and are always on the search for new inspiration. Like any good craftsperson they take some amount of pride in their tools and I've been blown away by how technical many can get on the electronics side! It's always funny to see Reverb auctions go up for famous musicians and finding out a bassist in a pop punk band owns a bunch of weird synthesizers :)

Simple one to two knob pedals are a big deal but you'll see a very large number of pros touring with extremely complicated modeling setups and all sorts of gadgets. At a certain point you really know what you want, and having the ability to dial that in is important! I tend to gravitate towards simplicity in a band setting but I know a lot of people who want dirt pedals with 10 knobs so they can dial in the sounds they hear in their heads.

Re: Eurorack Knob Idea

#30

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.

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

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