# Fast prototyping **URL:** \ **Category:** DIY STUFF\ **Created:** [June 30, 2020, 8:09pm UTC](https://lookmumnocomputer.discourse.group/t/fast-prototyping/1349 "2020-06-30T20:09:06Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![Bitnik](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/bitnik/32/274_2.png) [@Bitnik](https://lookmumnocomputer.discourse.group/u/Bitnik)\ **Post date:** [July 13, 2020, 5:28am UTC](https://lookmumnocomputer.discourse.group/t/fast-prototyping/1349/41 "2020-07-13T05:28:24Z")
It’s not that I’m naturally methodical. I really do work very slowly even when I could work faster. It’s mostly laziness. I like to eliminate things like sawdust, the use of bespoke services over which I have no control such as PCB fabs, and things that just “look wrong” to me. I still have a breadboard set up to play around with op amp configurations but I haven’t started testing in over three weeks because it never felt like the right time. ---
**Author:** ![Bitnik](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/bitnik/32/274_2.png) [@Bitnik](https://lookmumnocomputer.discourse.group/u/Bitnik)\ **Post date:** [July 19, 2020, 11:21am UTC](https://lookmumnocomputer.discourse.group/t/fast-prototyping/1349/42 "2020-07-19T11:21:08Z")
Meanwhile here’s my low tech answer to front panel text labels. I bought a couple of cheap stencil sets on Amazon. This shows some doodling I did last night to test the feasibility of this for front panel designs. I’m using a standard A5 panel size. The photograph shows the stencil set alongside an A5 panel, and on top of the panel lies a bit of scrap paper on which I doodled last night with three different stencils using a coloured marker pen. As this was a test I drew the guide line in marker but in real life any guide lines would be drawn in erasable pencil. A5 is 148mm by 210mm, or 5.8 x 8.3 inches for people still using old money. ![IMG_20200719_121112475](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/2/2b0c950dd04d01c8993582b7250ecc9fd16ae045.jpeg) How’s my kerning? ![](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/e/e2c189c8777ab140d8b5fd65e6d3bfd7be07831a.png) ---
**Author:** ![ChristianBloch](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/christianbloch/32/56_2.png) [@ChristianBloch](https://lookmumnocomputer.discourse.group/u/ChristianBloch)\ **Post date:** [July 19, 2020, 3:11pm UTC](https://lookmumnocomputer.discourse.group/t/fast-prototyping/1349/43 "2020-07-19T15:11:50Z")
Kerning is looking ace 👍 ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/6/6e2711d342345bba7d20353e25928611963f22cd.jpeg) ---
**Author:** ![Maxhirez](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/maxhirez/32/42_2.png) [@Maxhirez](https://lookmumnocomputer.discourse.group/u/Maxhirez)\ **Post date:** [July 19, 2020, 3:51pm UTC](https://lookmumnocomputer.discourse.group/t/fast-prototyping/1349/44 "2020-07-19T15:51:12Z")
Can’t beat: ![](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/9/9341b41078a1b73a0e31e181f242a5d0a398fc2d.jpeg) ![](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/8/8167964c8b1b9ebf4c4eaa5400509959cba017b3.jpeg) ---
**Author:** ![Bitnik](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/bitnik/32/274_2.png) [@Bitnik](https://lookmumnocomputer.discourse.group/u/Bitnik)\ **Post date:** [July 19, 2020, 3:57pm UTC](https://lookmumnocomputer.discourse.group/t/fast-prototyping/1349/45 "2020-07-19T15:57:08Z")
I want a lot of my panels to have pictograms rather than text, so I’ve ordered some stencils that contain promising designs. There doesn’t seem to be much in the way of a visual design language for modular synthesis, like the ones that exist for consumer electronics. I’m going to have to make my own, perhaps gleaning some inspiration from early Serge panel designs. ---
**Author:** ![Bitnik](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/bitnik/32/274_2.png) [@Bitnik](https://lookmumnocomputer.discourse.group/u/Bitnik)\ **Post date:** [July 19, 2020, 7:02pm UTC](https://lookmumnocomputer.discourse.group/t/fast-prototyping/1349/46 "2020-07-19T19:02:26Z")
Back to mignon construction. These are three short lengths of copper wire inexpertly soldered to a three pin screw terminal. This was my second attempt. On the first attempt (shown to the right) I managed to melt the plastic case of the terminal block. A resistance test shows good conductance from the terminals to the wires. As I said on [the Mail Day thread this morning](https://lookmumnocomputer.discourse.group/t/mail-day-thread/101/1290), the idea is to create a tripod bearing the Eurorack power and solder all the electronics (point to point style) between the legs. The whole thing gets drenched in clear epoxy resin, with the terminal sticking out at the top, and any other connections coming through the surface either separately or via a header strip. The resin dries hard and protects the circuit. I call this general style of construction _mignon vitrine_ (literally, “showcase mignon”). This particular construction method is _vitrine tripode_ (“tripodal showcase”). It’s sitting in an ice cube tray to check that I can pour the resin correctly and achieve the necessary coverage. ![IMG_20200719_193644531](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/5/51e6e3319779360b954968b1a088ca1be9f06101.jpeg) And here it is from the side showing my tragically bad soldering. ![IMG_20200719_193702484_BURST002](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/3/307cc6887e574e7ca1edcfa9db2f792510369403.jpeg) ---
**Author:** ![Bitnik](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/bitnik/32/274_2.png) [@Bitnik](https://lookmumnocomputer.discourse.group/u/Bitnik)\ **Post date:** [July 19, 2020, 9:27pm UTC](https://lookmumnocomputer.discourse.group/t/fast-prototyping/1349/47 "2020-07-19T21:27:36Z")
While I recharge my spiritual batteries after that gruelling 10 minute soldering session, I’m going to look at the kind of thing one would want to label in a typical Kosmo/Eurorack system. Signals, obviously. I think I’d like to use black binding posts for earth, and some other colours at the banana jacks to signify trigger, gate, V/Hz, CV, serial in and out (including MIDI), audio in and out, and whatnot. So that’s basically a bunch of coloured washers. Symbols for functions including sine, saw, triangle, square, and so on. Those already exist. PWM, a little tricky. Perhaps just a drawing of a square wave with successive pulses being of different lengths. I’m of the opinion that LFO may not be a useful distinction. Isn’t an LFO just an oscillator tuned to a really low frequency? Perhaps I need to think more about this. Cutoff and resonance? Scissors and bell, perhaps. Many more items to contemplate. Just making a start. ---
**Author:** ![fredrik](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/fredrik/32/682_2.png) [@fredrik](https://lookmumnocomputer.discourse.group/u/fredrik)\ **Post date:** [July 19, 2020, 10:03pm UTC](https://lookmumnocomputer.discourse.group/t/fast-prototyping/1349/48 "2020-07-19T22:03:15Z")
The patch and tweak folks have a bunch of symbols here: [http://patchandtweak.com/symbols/](http://patchandtweak.com/symbols/). They’re designed to describe patches, not modules, but may provide some inspiration. In [the book](https://lookmumnocomputer.discourse.group/t/mail-day-thread/101/216), they mention the following prior works: - Liner notes for _[Nonesuch Guide to Electronic Music](https://www.youtube.com/watch?v=mqhFvITV7kM)_ (Beaver and Krause, 1968) - _Electronic Music: Systems, Techniques, and Controls_ (Strange, 1972) - _Patch Notation: A Business Approach_ (Bugg, in [Synapse](https://en.wikipedia.org/wiki/Synapse:_The_Electronic_Music_Magazine) March/April 1978 ([PDF](https://monoskop.org/images/d/dd/Synapse_Vol_2_No_5.pdf))) - [Serge Modular Music System](https://en.wikipedia.org/wiki/Serge_synthesizer) manuals. ---
**Author:** ![Bitnik](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/bitnik/32/274_2.png) [@Bitnik](https://lookmumnocomputer.discourse.group/u/Bitnik)\ **Post date:** [July 19, 2020, 11:11pm UTC](https://lookmumnocomputer.discourse.group/t/fast-prototyping/1349/49 "2020-07-19T23:11:33Z")
Those symbols are great for ideas, though I note that the items themselves are under a restrictive “no derivatives” licence. So I couldn’t upload one of the symbols to a SVG editor, tweak it and then post the result here. What I could do though is reinterpret the items using my own artwork, which I could adapt as I please. So in the end it’s not unreasonably restrictive. They just want to retain editorial control of their own artwork and anything directly based on it, which is fine. ---
**Author:** ![Bitnik](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/bitnik/32/274_2.png) [@Bitnik](https://lookmumnocomputer.discourse.group/u/Bitnik)\ **Post date:** [July 20, 2020, 10:58am UTC](https://lookmumnocomputer.discourse.group/t/fast-prototyping/1349/50 "2020-07-20T10:58:05Z")
I also looked at the third reference you listed from Patch and Tweak, the 1978-datelined 2nd issue of the synth magazine Synapse. Richard Bugg’s article is useful as a means of bringing a quasi-mathematical discipline to the matter, and its brevity is praiseworthy. I know there are many more recent attempts at this. One of the reasons I’ve ordered a number of digital displays for my prototyping efforts is the knowledge that much information in a hybrid system is subject to rapid change, so at least part of the information to be displayed is a pictorial representation of the software patch as it relates to the physical controls. I’ll be adopting or developing a notation that can convey useful information even on the smallest of useable panels. Perhaps I’ll use the Faust DSP notation if it can fit into the panel space. [http://faust.grame.fr/doc/manual/index.html#quick-start](http://faust.grame.fr/doc/manual/index.html#quick-start) ---
**Author:** ![fredrik](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/fredrik/32/682_2.png) [@fredrik](https://lookmumnocomputer.discourse.group/u/fredrik)\ **Post date:** [July 20, 2020, 9:33pm UTC](https://lookmumnocomputer.discourse.group/t/fast-prototyping/1349/51 "2020-07-20T21:33:31Z")
The interview with Froese was pretty entertaining. I especially liked the bit about how they had studied the sequencer for five full years, and then Moroder shows up and ruins everything… [![](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/9/9ba062c990f01d6d63da726a0781cecda7d1bd51.jpeg "Daft Punk - Giorgio by Moroder (Official Audio)") ](https://www.youtube.com/watch?v=zhl-Cs1-sG4) Will have to go find the other issues, I think. ---
**Author:** ![Caustic](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/caustic/32/15588_2.png) [@Caustic](https://lookmumnocomputer.discourse.group/u/Caustic)\ **Post date:** [July 20, 2020, 10:12pm UTC](https://lookmumnocomputer.discourse.group/t/fast-prototyping/1349/52 "2020-07-20T22:12:42Z")
Yeah, this was a fun little aside for this album. Very welcome. ---
**Author:** ![Bitnik](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/bitnik/32/274_2.png) [@Bitnik](https://lookmumnocomputer.discourse.group/u/Bitnik)\ **Post date:** [July 21, 2020, 11:20am UTC](https://lookmumnocomputer.discourse.group/t/fast-prototyping/1349/53 "2020-07-21T11:20:09Z")
Soon I’ll be building mignons for real. I’ll be building 100nf bypass capacitors across each power supply rail. I notice that low ESR versions are recommended, but there doesn’t seem to be an operational standard for the term. Naturally I do want my bypass to have a low equivalent series resistance at the damped end of its spectrum, so I imagine I will want them. So how important is a specifically low ESR component in this role? Would a generic ceramic disc capacitor not do a decent job in the context of an analogue modular synthesizer? ---
**Author:** ![fredrik](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/fredrik/32/682_2.png) [@fredrik](https://lookmumnocomputer.discourse.group/u/fredrik)\ **Post date:** [July 21, 2020, 11:53am UTC](https://lookmumnocomputer.discourse.group/t/fast-prototyping/1349/54 "2020-07-21T11:53:01Z")
ESR is usually only a concern for electrolytic capacitors; ceramics tend to have very low ESR also compared to low-ESR electrolytics. Any cheap class II ceramic will be good enough; odds are other parts of your circuit will go out of spec long before these cause any problems. Note that 100 nF bypass capacitors should ideally be located close to the IC supply pins, so you want to view them more as a part of the IC than part of the mignon. ---
**Author:** ![Bitnik](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/bitnik/32/274_2.png) [@Bitnik](https://lookmumnocomputer.discourse.group/u/Bitnik)\ **Post date:** [July 21, 2020, 12:03pm UTC](https://lookmumnocomputer.discourse.group/t/fast-prototyping/1349/55 "2020-07-21T12:03:15Z")
Thanks. Good point about putting the capacitors as close as possible to the power supply pins of the IC. ---
**Author:** ![Bitnik](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/bitnik/32/274_2.png) [@Bitnik](https://lookmumnocomputer.discourse.group/u/Bitnik)\ **Post date:** [July 21, 2020, 3:13pm UTC](https://lookmumnocomputer.discourse.group/t/fast-prototyping/1349/56 "2020-07-21T15:13:14Z")
On colour coding my banana jacks, I’ve noticed today that somebody was buying very posh Befaco nuts in Serge colours for use with Eurorack modules. I’d like that but I’m not using Eurorack and in any case they are expensive for what they do. On researching, I notice that those paper reinforcement rings they sell for use with ring binders are approximately the right size to stick over my banana jacks. They can be coloured with a simple marker pen and they’re very cheap. Banana jacks are themselves available in multiple colours but I’d prefer the flexibility of choosing my own colours at the time of need. > **[2000 Pack, Hole Reinforcement Ring Labels Stickers - White: Amazon.co.uk: Office...](https://www.amazon.co.uk/dp/B07V9FL8V4/ref=cm_sw_r_cp_apa_i_HxWfFb2YXDMCQ)** > > Outer Diameter: 13 mm. Inner Diameter: 6.5 mm ---
**Author:** ![Bitnik](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/bitnik/32/274_2.png) [@Bitnik](https://lookmumnocomputer.discourse.group/u/Bitnik)\ **Post date:** [July 21, 2020, 7:46pm UTC](https://lookmumnocomputer.discourse.group/t/fast-prototyping/1349/57 "2020-07-21T19:46:37Z")
So here’s a Y cable I made up using a 3.5mm inline mono jack and a couple of 4mm stackable banana plugs. A 3.5mm white Eurorack-style patch cable from my Crave is connected to the inline 3.5mm jack. I ordered the 3.5mm jack by mistake instead of a 3.5mm mono plug, but as I already have 3.5mm to 6.35mm mono leads I get to pretend I was being far-sighted and producing a single conversion lead that can work with both Kosmo and Eurorack patchboards. The 3.5mm mono ring (edit: I mean _sleeve_) is connected to the black cable with the black 4mm banana plug, and that’s supposed to go to a 4mm binding post connector on my synth (whenever I actually build the thing) and links the earths together. The 3.5mm mono tip is connected to the red cable with the red 4mm banana plug and carries the signal to or from my synth. If this is confusing you, the principles of banana plugs are discussed near the top of this thread. Suffice to say this simple Y cable performs the same function as a conversion module and occupies no extra panel space. Took me less time to make it up than to explain it. About ten minutes, novice level soldering skills. ![IMG_20200721_203305418](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/3/370735671e86f13cc16960324a8eb126f19223ac.jpeg) ---
**Author:** ![ChristianBloch](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/christianbloch/32/56_2.png) [@ChristianBloch](https://lookmumnocomputer.discourse.group/u/ChristianBloch)\ **Post date:** [July 21, 2020, 8:29pm UTC](https://lookmumnocomputer.discourse.group/t/fast-prototyping/1349/58 "2020-07-21T20:29:53Z")
> [@Bitnik](#): > > The 3.5mm mono ring is connected to the black cable Unless it’s stereo, wouldn’t that be the sleeve, not the ring? ---
**Author:** ![Bitnik](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/bitnik/32/274_2.png) [@Bitnik](https://lookmumnocomputer.discourse.group/u/Bitnik)\ **Post date:** [July 21, 2020, 8:37pm UTC](https://lookmumnocomputer.discourse.group/t/fast-prototyping/1349/59 "2020-07-21T20:37:05Z")
Yes, it’s called the sleeve. I got the terminology wrong there. I’ve added a clarifying edit. ---
**Author:** ![Maxhirez](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/maxhirez/32/42_2.png) [@Maxhirez](https://lookmumnocomputer.discourse.group/u/Maxhirez)\ **Post date:** [July 21, 2020, 11:04pm UTC](https://lookmumnocomputer.discourse.group/t/fast-prototyping/1349/60 "2020-07-21T23:04:02Z")
Looks great! The only issue I can see is that Neve is missing from the shot. 😉 [Previous page](https://lookmumnocomputer.discourse.group/t/fast-prototyping/1349.md?page=2) [Next page](https://lookmumnocomputer.discourse.group/t/fast-prototyping/1349.md?page=4)