Design Clipboard is a collection of thoughts about interface design (and design in general), sometimes loosely organized around a topic.
I had been thinking about knob scales for quite some time, when I bumped into this discussion on modwiggler.com.
The core point of the whole discussion is summed up pretty well in the initial post:
Even if the knob value is often somewhat different from where the dial is due to external CVs causing offsets etc, markings around knobs/dials is still useful for a reference point when you’re wiggling and want to go back to a set point.
helix on modwiggler.com
For years I had been a less-is-more advocate for panel graphics. In fact, we never used any scales around knobs on the Mutable Instruments panels. As I gained more experience, talked to other modularists, and spent time with the instrument, I realized that things are not that easy (they never are, are they?). In some cases it’s fine to just have a knob and nothing else. But there’s many situations where it’s useful to have a visual reference for the knob’s position, and others where it’s absolutely essential. The approach to playing the modular that the designer wants to foster has to be taken into account as well. For some it’s more about the exploration, about happy accidents, and listening instead of looking. In this case, knob scales will often be deliberately avoided.
After we put out Rings, we found out that many people were using the decorative graphics around the frequency and structure knobs to memorize sweet spots.
At one point I decided to look further into this matter and asked some people on the Modwiggler and lines (llllllll.co) online forums, what they would prefer among a series of generic examples.
I received quite a few responses, and I would like to take a moment to thank everybody who’s been sharing their thoughts and experiences in these threads!
I wanted to see how much visual indication people were seeing as useful and if there was a threshold above which it was too much.
A little disclaimer: This is definitely not a rigorous scientific investigation into the matter. Also, I don’t have definitive answers here as this is still an ongoing process. Still, this helps me to get a better understanding of how musicians feel about it, especially in combination with my wider experience, and intel from my clients.
This said, below you can see the configurations I showed to people:
Discourse, the forum platform lines (llllllll.co) uses, lets you do polls, so I created one there, here’s the results:
My main takeaways are:
- As usual, there’s diverging opinions. Some people love to have as much visual marks as possible, others really enjoy the absolute minimalism.
- Some controls do benefit more than others from having scales. It’s the kind of thing that needs to be evaluated on a per-parameter basis.
- Alternating marks of different shapes or sizes is useful, but there needs to be a certain balance. A bigger mark every three small ones seems like a good solution for medium-sized knobs.
- Too many marks make the scales hard to read, especially if they are looking very similar. On the other hand, if there’s too little of them, they are not really useful. This is of course highly dependent on the knob size.
- While everybody seems to approach this in a different way, there’s a good share of people who memorize knob positions referencing them to the positions on an analogue clock.
Nowadays most potentiometers have a turning radius (from the minimum to the maximum position) of 270°. This creates some further challenges, especially when trying to match knob scales with the positions on a clock. Since the dead zone of 90° on the bottom does move the start and end marks away from the 5 and 7 o’clock positions.
With a 300° turning radius you could have 11 marks (0-10) and have each match clock positions. With a 270° radius that doesn’t work (see knob #2 below).
I showed people the above designs to evaluate some situations related to that. Both are common compromises: The left one matches clock positions, but has 13 marks (0 – 12), the right ones goes from 0 to 10, but the marks don’t match those on a clock.
The only solution where you would have a 0 – 10 scale and have ticks at all major clock positions is the one below. But this is also a compromise, because it’s only the small dots going from 0 – 10, the bigger dots go from 0 to 8. You can of course reverse that, but then you loose the big dot at 12 o’clock.
From what I could find out, there’s no clear winner for any of the above images.
It’s a tricky choice to make, and it generally depends a lot on the actual parameter, the size of the knob and the overall style of the panel.
Going Futher
There’s quite a few opportunities for interesting designs that can be explored with knob scales.
I remember the Waldorf Rocket being a big inspiration when it came out. There’s a couple of knobs that do different things based on the mode they are in (eg. the wave knob). The designers (Designbox) did a great job at marking sweet spots for the different modes around the controls.
One thing we did with Chronoblob 2, and which we should do more often, is marking relevant and interesting parts of the turning range. In this case the range where the feedback amount sets the module into self-oscillation. Seeing this on the panel can be quite useful, both if you want the self-oscillation to happen or if you want to avoid it.
Synth Panels Designer
A quick way to create knob scales is the free Inkscape add-on Synth Panels Designer by the people behind Faselunare and Soundmit. It comes with a bit of a learning curve, but once you have figured it out, it can be super useful to make quick mockups and layouts for eurorack modules and synth panels.
I really like the knob scales function, since that’s one thing that is otherwise a bit laborious to make. Especially for more detailed graphics.
It’s a free download at:
As a side note, I recently installed Inkscape, because v. 1.3 added a lot of new features, and I wanted to see how some compared to other vector drawing packages. I hadn’t been using it in years, but I’m really surprised by how far it has come in the meantime! Definitely worth a look if you need that kind of software.