Transistor Ladder Filter panel

I made a Kosmo version of the transistor ladder filter based on the Kassutronics design.

And came up with this panel:

Now I am looking for your feedback! :slight_smile:
I opted for using symbols for frequency and resonance, because I could not find a good-looking place for the letters xD It is reversible, so maybe I will do some letters on the backside.
I am not completely sure about the font, maybe a littel too playful in contrast to the exact lines of the symbols…
What do you think?


I like it! It’s got style and character without being un-utilitarian. Can I assume the tiny dots and letters near the resonance knob are to be disregarded? Should it say “Transistor” rather than “Resistor” at the top? I can see the font as being polarizing, but I like it well enough.

I really like it, though the wobbly circle around the top (I assume Frequency?) is the wrong way around to me, bigger wobbles look like a more open filter. Are the dots LEDs? The labels for those are super tiny. And I’m a labels above. I do like the font. And the Resonance squiggles look great!

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The “bigger wobbles” look to me like longer wavelength, which is lower frequency, so to me it’s the right way around.

Thank you! Yeah, should be Transistor of course! The tiny labels are for trimmer pots, I am unsure how to handle those…
Bigger (more spaced out) wobbles mean lower cutoff frequency, exactly!
I am also very happy with the resonance wobbles, they are rotated Legendre polynomials, I remembered them from my potential theory(?) lectures when we Computed the gravitational potential of the earth. Have not used them since xD


I get it. Still looks wrong to me :stuck_out_tongue_winking_eye:

Looks super fresh man! Really like the graphics in place of labels and the “American horror story“ font

Would love to hear more about your process for making those!

Maybe we need a panel art thread

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Made an update, a bit more amplitude on the wiggles, everything a bit bigger…

And here is the pcb. Still need to check that I put the jack sockets on the correct side of the daughterboard… but I added some Molex as a back up :wink:


I hope it isn’t too late to proof read your panel design. In the module title at the top, you have omitted the second S from the word “transistor.”


Thanks!! I can still change it!

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No problem. Incidentally your font design rings a very old bell with me. Is it based on the inner sleeve of Led Zeppelin IV? The only Zep album I ever owned, and I remember the strange rendering of the letter o.

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The font is Shnobel by Vova Egoshin. Looks similar, no idea if it was a source of inspiration…


Deep pull, there :grinning:

To me it seems like yesterday.


Those os remind me of the lowercase ones in Copacetic, one of the fonts I use on my panels:

but I only use uppercase because I find the lowercase too hard to read.


Love the woobly lines that show increased frequency without any words!

Talking of panels, I confess I imagined there would be a set of universal pictograms, but I haven’t seen any such symbols on panels. I haven’t really got to the point where I will want to design panel layouts yet, but it does appear to me that simple pictograms would be far superior to wording. Use of coloured washers on jacks would also help to identify types of socket. Another possibility is simply to set a standard for panel layout that places controls and jacks in predictable locations. This would reduce the need to distinguish inputs from outputs, for example.

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The “EuroSynth” folks have a proposal:

but not sure who’s in a position to get several hundreds of manufacturers to agree on anything.

As for pictograms, there’s always Brian Eno’s approach:


I like the EuroSynth proposal. While the red and green washers shown here are very difficult for me to distinguish due to my colour blindness, it would be easy enough for me to adapt the idea.

I’m not really interested in seeing designs become universal, I just want something I myself would find aesthetically pleasing.

I suppose I’d want symbols to distinguish VCO, VCA, VCF, envelope generator, sequencer, and the like. I’m not really interested in the VCO/LFO distinction so that reduces the number of different symbols I’d need. Attenuation controls, function toggles, encoders, manual triggers and so on would need symbols. Perhaps a sheep might make it onto my panels, but I think I would favour simple geometric patterns. I’m not a fan of woolly thinking or woolly music.


From the Wikipedia article Serge synthesizer:

Serge adopted a series of geometric designs denoting signal types, input, outputs, and triggers. Colored 4 mm sockets were used for most connections – blue, black, and red jacks; blue for (unipolar) control voltages, black for bipolar signals (NOT necessarily AC coupled) and red for pulse/gate signals, although these were not rigidly enforced. Later, other colors were introduced, e.g. yellow for triggers.

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