Oooh! Can you add a sub oscillator to that back pedal there? Im joking! Genius was the right move though. 
No please don’t worry. Im not offended. I just had a moment where I thought my runaway brain had run too far off the community track.
Ideas are pretty much all I do. I’m mostly bedridden but have a 176 IQ and had my first IT contract at 7 with ICL. When my brain is working then ideas pish oot (excuse the Scots) but when my brain taps out I can’t even wipe my own ass.
This forum is an outlet for me. Its a place I enjoy spending what time I get. And for just a second I thought I’d become a very foolish interloper as layers of impostor syndrome fell.
This was not you. It was all me and I apologize for any hint of Beef (right word?).
Let me say sorry again for getting touchy. I can’t “do” much right now but I’d still like to contribute when can and when i can’t I’ll still contribute (but making less sense).
Farabide is Scots for ‘where I live’. My friends call me Sandy and so should you all.
Now sorry for bumming the vibe… thanks for listening. As you were.
The speaker wire is something called CCA (copper clad aluminium). This has been measured as having 68% of the conductivity of pure copper wire, but it’s a lot cheaper. Since CCA speaker wire is considered to be perfectly acceptable at up to 5 metres or so into a 4 ohm impedance (16awg, too, somewhat thinner than mine) I don’t think the difference in material will affect its use for synth patching (phew!)
Another thing I’m supposed to be working on is the construction method for my submodules. These will typically be so-called “dead bug” arrangements of passive components around an op amp chip and maybe one or two of those little 8-legged ATtiny85 MPUs. The idea is that they’ll transform incoming and outgoing signals so that the analogue and digital parts of a hybrid module can concentrate on doing what they do best.
Actually soldering the submodule is easy enough but keeping it electrically and mechanically sound is a job that needs some thought. So far I’ve investigated various potting techniques. I could alternatively enclose each submodule in a small enclosure with protruding wires. Crimping could be involved.
Dead bug is great. Can I suggest you splay out ic mount legs and fix the mount in place to give yo the option of replacing op amps etc if they cook.
The Attiny is a great option as they are so versatile. I plan to use them but I’ll be modifying a PCB design to make using them more straight forward and easier to adapt to functions and the use of eprom. I’m a long way off the build for these but I’ve scrounged up about 30 At’s and some other mcu already as they’ll probably be antique by the time I’m ready. Id be interested to learn more details about your ATtiny plans/functions. I’ll also be using teensy as an oscillator bank, PIC for MIDI merge and timecode offset for some solenoid and servo mechanics once I get another autoharp or two. (May have to build them). I’ve been looking into some MIDI and synth control using a raspberry pi.
I’m still looking for a name for these submodules. Perhaps I’ll call them singletons in honour of the 1960s Blue Peter presenter Valerie Singleton who used to present bizarre DIY projects so you could make a jewelry tray for your mother or a pipe rack for your father using detergent bottles and sticky backed plastic. That’s very much the aesthetic I’m looking for, at least behind the panel.
The ATtiny85 is physically almost identical to a 555 chip, with only 8 legs. It lacks a UART so for practical reasons I’d use it in singletons that can be used like a lego brick. No reprogramming. They can be reprogrammed but the point is I wouldn’t want to at this scale.
Moving to board solutions, Arduino Nano is a great compromise of form factor, but for some of the singletons I want it’s a bit overkill and I’d probably use a Digispark (ATtiny85) or DigiSpark Pro (ATtiny167), both of which are USB programmable. I can program this kind of chip in assembler if necessary but they are also compatible with the Arduino software platform.
I’m thinking aloud about singletons. As I’ve hinted previously, I see a need for small Lego brick-like circuits that perform a function that can be broadly classed as signal conditioning. For example, an incoming 1V per Octave signal may need to be scaled and possibly digitised so it will make sense to a 3V3 system such as a Beaglebone Black. It should have, say, dip switches or jumpers, and trimmers, so its precise operation can be adjusted to the circumstances.
Digital signals can also be conditioned. A MIDI stream can be filtered so as to reduce the load on the main processor, for instance, or to switch, split and merge channels. Some singletons may act as USB hubs or Bluetooth transceivers. Or noise sources, or other signal sources.
Oh, and as for potting and other aspects of the physical construction, I really love this instructable.
And overall, I think I prefer to call them Vals. Same person, snappier name.
Thinking about panel design, I’ve decided to order 50 A5 address labels (due early next week). So in principle at least I can print out a neat design and stick it directly onto the greyboard. I’ll test this and show the results as soon as I can.
This is fairly inexpensive, £5.50 for 50 A5 adhesive sheets suitable for inkjet or laser printing, and it’s not as if we’ll have no use for address labels if this doesn’t work out.
Singletons and Vals didn’t work out for me. I’m calling them mignons with the French pronunciation (or as close as I can get in English speech without sounding like a poseur.)
This choice of pronunciation is because I don’t want to find out what the film Minions is about. Mignons are going to be small and cute, so the borrowing makes perfect sense to me.
If you open them up are they fillet mignons?
Great name btw
My little cases arrived this morning. Here’s one idea that immediately sprang out at me (always a difficult moment when I haven’t put my trousers on). Here’s what I did.
The idea is that the case interior protects the permanent part of my semimignon (or whatever name I’ll dream up for this variant) while the little external self-adhesive breadboard sits outside and provides a little space for programmability or even blatant adhocery. For instance the interior could protect a tl074 and its associated power supply, while the exterior can hold the resistors pertaining to a particular configuration.
Did I say that I have a few dozen tl074s?
PS: ignore the IC, it’s an ATtiny85 that happened to be onboard when I picked up the mini-breadboard (mignonboard?)
I didn’t know that was a stereotype internal to my ancestry until quite late in my life, but when I learned of it, it sure explained a lot!
Bear in mind that copper wire was invented by two Scots brothers fighting over a penny
Well the greyboard and velcro panel system passed the first patch test with flying colours. There’s a bit of give in the panel but the velcro holds it fast to the bookcase shelf during a rather brusque insertion and removal of the banana plug. I’m confident that this fixing won’t give me problems in everyday use.
Looks solid! Also love the narration. Straight and to the point 
, as my English teacher in high school used to say.
You may have noticed I’m a bit more loquacious in the written word.
I also had a panel of 2mm greyboard with 6.35mm jacks. Fitting velcro to that panel and repeating the test with a 6.35mm patch cable was not successful. Banana plugs are simply more suited physically to this kind of application, in my opinion. I think there’s probably a prejudice against them because they’re a little counter-intuitive to people who are used to cables having two wires in everyday life.
Since my only current synth is the semimodular Behringer Crave I’ve ordered some 3.5mm mono plugs. I’ll make up some Y cables so that I can send interesting signals from the Crave (which has Eurorack-style 3.5mm jacks) into my banana system. Eugh, soldering, because I can’t find any screw-connection 3.5mm plugs.
Elsewhere I’ve discussed my dissatisfaction with the Eurorack power distribution system. Here’s a proof of concept test with 5mm pitch screw connector block and a 0.75mm three core electric flex. The flex is designed for the UK market which has a yellow and green earth wire, blue neutral wire and brown live wire. I propose to use brown for +12V, blue for -12V and green/yellow for earth. As the cabinet will contain no live wires (being fed by a 12VAC wall wart) this repurposing of mains cabling is okay for internal power distribution. It’s economical and easily sourced too.
Also shown in this photo is an A5 greyboard on which I stuck an A5 self-adhesive label. As I hoped, this produces a very smooth high-contrast surface which can be preprinted and/or painted.
Also, a happy discovery. The pins of these terminal blocks are almost certainly far too big to fit normal stripboard holes, some drilling will obviously be needed. But, the pins do fit the mini breadboard on top of my mignon à chapeau mockup without complaint.
As the mignons à vitrine will use dead bug construction, stripboard will not be used. But I’ll have to come up with a solution for the larger modules that use stripboard.
That bloodstain is Neve the greyhound’s, but don’t worry, it’s just the outcome of a little surgery on one of her hind paws on Thursday morning. The wound had to be kept undressed so she bled a little on the furniture and bedding. Friday, my wife tells me, she went for an hour-long walk, and she’s almost back to normal.
Glossary
Mignon - a small reusable element designed to perform a simple signal-processing job. Typically used to link up analogue and digital components of the prototype so that they can work together without pain.
Mignon à boîte - a mignon built around a small enclosure which protects the delicate electronics from mechanical damage.
Mignon à chapeau - literally, a mignon with a hat on. A mignon topped by a small breadboard to make fast reconfiguration easy during prototyping.
Mignon à vitrine or mignon en verre - a mignon in which the mechanical protection is provided by a layer of resin.
Mignon poilu - a mignon with a male header on top, which can be used for configuration to produce variants from a standard circuit.
Mignon à puce or mignon digital - a mignon containing a microchip, typically manipulating digital data.
Mignon analogique - a mignon containing analogue components, typically operational amplifiers.
Vitrine tripode - a style of construction of a mignon vitrine in which the circuit is soldered between the legs of a stiff wire tripod or in French, trépied, which provides both electric power in use and structural integrity during construction. A three-pin terminal block at the apex keeps the wires together and provides power to the trépied.
Vitrine à sandwich (or vitrine à sandwiche) - a method of building up a vitrine in several layers of resin. The main advantage is keeping curing times reasonable, but this construction method also raises the possibility of using various modelling techniques such as using a different pigmentation for each layer.
Tarte aux cerises - (literally cherry pie) a method of constructing a vitrine in which existing transparent solids such as cheap acrylic “scattering diamonds” are used either to reduce the quantity of resin needed or to create a solid scaffolding or armature upon which the circuit is built, usually both. The solid items are referred to as cerises.
Français - a language spoken by many humans, used here to produce a distinctive nomenclature.
I really like where you’re going with this and how methodical you are. Also glad Neve’s OK.