The 2020 Show Us Your DIY Builds Thread!

[J3RK]

I built a Quad Function Generator based on the Intellijel Quadra + Expander (which was based on the Buchla 281) into a 5U module. I used a Panel Board to eliminate panel wiring and a Translator Board to connect the Panel Board to the Circuit Board without having to compromise the layout of either one. Here is the finished module:

15_Finished_QPG.jpeg

And here is a couple of pictures of the board stack (every board has circuitry on it -- the main Circuit Board has all of the Quadra circuitry, the Translator Board in the middle has all of the Expander circuitry, and the Panel Board has circuitry for the Quadrature Mode switches -- on the Intellijel unit, these are 4PDT switches, but here I opted for SPDT switches and DG333s):

7_Board_Stack_1.jpeg
8_Board_Stack_2.jpeg

I'm actually considering offering these for sale on Modular Grid. What do y'all think of that?

Very nice! My current system only has two function generators. I need to come up with a quad version like this.

[soup]

cgs sequential switch in frac...

[hox3d]

Beautiful, as always.
What are those switch caps? Do they feel rubbery? At the moment I use some from NKK, but I'm not satisfied with the feeling/finish.

[gnsk]

I am in awe of your deadbug skills. Cool! I have the Noise Reap sampler built using the same chip. Lo-fi but a lot of fun. Your take on it looks much more complete.

(have you heard of this amazing new circuit board technology that has been invented recently? It's like taking a photo of all your wires and then telling your computer to print it out!)

thanks! Also i looked your Noise Reap's circuit. It helped me a lot to understand.
the amazing new technology's name? i searched but only got the "3D printed electronics(PE)"
anyway point-to-point is lots of fun, like making the buildings and pipes in small module.

[soup]

Beautiful, as always.
What are those switch caps? Do they feel rubbery? At the moment I use some from NKK, but I'm not satisfied with the feeling/finish.

Thanks. The switch caps are the soft touch ones from small bear...

http://smallbear-electronics.mybigcomme ... oft-touch/

Rubbery is a weird adjective, I don't know if that's good or bad? I'd probably describe these as grippy. I like them but they are only available in a few colors.

[hox3d]

Well, grippy seems better, and that's what I meant.

Thanks!

[gnsk]

"Radio Sender"

* radio transmitter in Eurorack format assemblage
* on/off, Attenuators, Frequency-up button
* 2 channel (stereo FM)
* left in -> right in normalized
* 3HP

* Radio Music -> Radio Sender -> HackRF one portapack -> back to modular;

maybe feedback loop, FM radio filter, detuned freq., noise from radio->delay, false demodulation(AM, NFM), interference, or some other SDR experiment

[synkrotron]

"Radio Sender"

Very neat indeed. I am impressed

[synkrotron]

Okay,

Having browsed through this topic a number of times I feel slightly, no, very embarrassed with what I am about to share with you.

A simple build, that is for sure, and a module that no doubt everyone has a go at in their early days, I would have thought.

Previously all I had made was even simpler passive attenuators.

This build is slightly more complicated and contains "real" electronic components.

I give you my attempt at a Passive Low Pass Gate. Well, two, so I guess that makes it a Dual Passive Low Pass Gate.

And, yeah, I know, it isn't really a LPG, but I sure do enjoy using my Meng-Qi DPLPG so that's another reason for giving this a go. Time for some photographs *gulp*:-









So, not only dodgy low light images (the last one took three seconds to expose) but a very shoddy effort.

I do enjoy DIY, providing it is doing something I enjoy. I have made all sorts over the years... Bookshelves, TV stands, a 12m^2 wooden shed, that kind of stuff. Stuff I hate is putting up curtain rails... Does my head in that one.

I have experience with soldering but I was fifteen at the time, now sixty. It is only since getting into modular that I started to solder more often.

I have no experience worth talking about with regards to "point to point" soldering. So that mess that you can see above I blame on that.

What do you guys do when it comes to point to point stuff? I didn't really have a plan. I was thinking of modelling each component in 3D using BricsCAD (similar to AutoCAD but a fraction of the cost) and then assembling the components in the virtual world first. But after thinking about that for ten minutes or so I decided that it would take too long and just made it up as I went along.

Although it is a DPLPG they are slightly different and the lower one uses another vactrol which has its LDR wired before the capacitors (I have put two capacitors in parallel, which sounded better on the breadboard). So I can use CV to alter the tone of the output. It's not that great but decided to stick to the plan.

I therefore started with the upper, and simpler PLPG and then building the second one once I had finished and tested the first.

I'm glad to say that they both function as expected.

I put a second LED as an indicator in series before the vactrol. I noticed that it was more usual to put that LED in parallel but during tests I found that I preferred the in series arrangement, sound wise. Without that LED I found the PLPG to be too fast and clicky and the second LED helps to get rid of that.

I haven't installed it yet because, although nothing short circuits at the moment, I would feel a lot happier once I have gone around a lot of the bare wires with some insulation tape. I am hoping that it isn't going to get too warm, which would probably cause the tape to sag away a bit. I'll probably take it out for inspection now and then just to make sure it is okay.


cheers, and thanks for reading about my first Big Build

andy

[gnsk]

What do you guys do when it comes to point to point stuff? I didn't really have a plan. I was thinking of modelling each component in 3D using BricsCAD (similar to AutoCAD but a fraction of the cost) and then assembling the components in the virtual world first. But after thinking about that for ten minutes or so I decided that it would take too long and just made it up as I went along.

i'm not using 3D CAD or some software for point-to-point soldering. real world is fast and intuitive to me. and desoldering is simple.

i'm doing;
* With color pencil on schematics, group the component with related component. i.e. TL072 with 104 cap and resistors, jack with resistor, PT2399 with related resistors, caps. "make module in module"
* in each group, soldering components as near as possible, without wire, only from component itself. layering.
* position and soldering the each soldered component behind jack or panel.
* wiring each groups.
* add power connector, it is also pre-soledred with beads, caps, diodes.
* make position, trying not to use additional wires, and not to far each to each. "topology"
* trying to support physikalisch each with each.

hopes helpful

[sduck]

Okay,

Having browsed through this topic a number of times I feel slightly, no, very embarrassed with what I am about to share with you.

That's beautiful! Love the point to point wiring. There should be more of that in synth diy.

[synkrotron]

hopes helpful

Yes, thank you very much

I think I did okay with my build with only 15 components, not including the jack sockets. I managed without printing out the schematics and I had them up on my computer screen instead. But I can see the advantage of being able to make notes for larger projects.

I didn't time my build but it must have taken at least three hours all together. Hopefully as I build more I will get a little bit faster.

That's beautiful! Love the point to point wiring. There should be more of that in synth diy.

Haha! I suppose it does have a certain organic beauty

[Dr. Sketch-n-Etch]

I love it! However, I believe that you would probably have an easier time if you used veroboard instead of point-to-point wiring. Also, your circuit would be more secure and less likely to touch other stuff behind the panels.

Incidentally, I just posted a video of my new 5U Dr. Octature build. Check it out on my thread Something New from Doc Sketchy

[synkrotron]

I love it! However, I believe that you would probably have an easier time if you used veroboard instead of point-to-point wiring. Also, your circuit would be more secure and less likely to touch other stuff behind the panels.

Yes, you are right, I should look into that veroboard stuff. In the meantime I wrapped it up with some insulation tape. Doesn't look so nice now but it is quite solid and I can no longer poke the LEDs back through the front panel

Incidentally, I just posted a video of my new 5U Dr. Octature build. Check it out on my thread Something New from Doc Sketchy

I'll do that now

[audioCTRL]

NLC "Delay No More 3"
* 18hp -> 10hp repackt
* For troubleshooting, tried to build each parts in module as module.

thanks andrewF!

delaynomore-vorne.jpg
delaynomore-dorsal.jpg

Lovely mess - DIY at its very best!

[Grumble]

Eeprom programmer for 82c512 (64k x 8) eeproms for a digital waveform generator under construction.

[gslug]

Eeprom programmer for 82c512 (64k x 8) eeproms for a digital waveform generator under construction.

FF5D9A89-C1DE-4126-B6B0-DD179769FC5D.jpeg

2737CC57-88D8-4EFA-8DC3-23B2BC40C026.jpeg

That's terrifyingly neat!

[Hutenberger]

Built some very basic modules on Stripboard with a somehow "rock and rollish" faceplate "design" ;-)
- Dual V/Oct VCO for Saw and Pulse
- Dual A=B*C+D Attenuverter/Shifter
- VCA lin/log based on MFOS
- Multiple (yay!)
- Power supply (wall wart + LDO style, not visible)
- Some basic In/Out/Send/Return jacks with passive Potentiometers as my other gear is 6,3mm jack based and only likes Line-Level signals.

this little rack sounds actually quite mighty

[synkrotron]

this little rack sounds actually quite mighty

Very nice

Which VCO did you go with? Or did you design it yourself? I am thinking I should be having a go at a 1V/Oct VCO, amongst other things.

[Hutenberger]

I built the circuit by myself, but i would rather call it "putting the building blocks together and playing around with some values" instead of "designing" ;-)
This is a simple Saw-Core to get started: http://electro-music.com/forum/post-292718.html
I derived the pulse/PWM from it by placing an op-amp as a comparator behind it and made the comparison-voltage adjustable.
The Sync can be achieved by placing a FET across the Capacitor.
For the Exp-Converter, this design is quite popular and works well: https://www.birthofasynth.com/Thomas_He ... t_0001.pdf
A quite similar circuit can be seen here: http://musicfromouterspace.com/index.ph ... 6&VPH=1132

[synkrotron]

I built the circuit by myself, but i would rather call it "putting the building blocks together and playing around with some values" instead of "designing" ;-)
This is a simple Saw-Core to get started: http://electro-music.com/forum/post-292718.html
I derived the pulse/PWM from it by placing an op-amp as a comparator behind it and made the comparison-voltage adjustable.
The Sync can be achieved by placing a FET across the Capacitor.
For the Exp-Converter, this design is quite popular and works well: https://www.birthofasynth.com/Thomas_He ... t_0001.pdf
A quite similar circuit can be seen here: http://musicfromouterspace.com/index.ph ... 6&VPH=1132

Thank you for the links

You seem to know your stuff. The only circuit I am familiar with is the astable multivibrator but I haven't even made up one of those for over 45 years.

[GrantB]

Solid state pultecs

[synkrotron]

Okay, it's me again, come to lower the tone of the Show Us Your DIY Builds Thread.

I have made many passive attenuators now and I will be the first to admit that they are not really worthy of posting here. But I thought sharing my latest passive attenuator module would at least give you a bit of a laugh.

Due to lockdown and all that I've been wondering how I could make a front panel. I only had a small scrap of aluminium sheet left and I tried some plastic but it was not stiff enough.

But then I spotted a sheet of 1mm thick mild steel underneath my workbench. I can't even remember when or why I got it, so it must have been there for quite a while. A little bit rusty... Then I thought, let's go for the Mad Max look.

Here's the front panel, cut to size using a hand held electric jigsaw and holes drilled with a hand drill. I have yet to get hold of a drill stand, but I am not sure it is worth bothering yet as I don't know how serious I am going to get with this DIY thing. I have a centre punch so I think I just about managed to keep the holes reasonable well spaced. I'm thinking I need to get some slightly more powerful reading glasses...



The hole at bottom left is a bit naff... I tried going from 2mm pilot to 8mm hole in one go. For the rest I went 2mm > 5mm > 8mm.

Components in place ready for soldering:-



Front of panel with knobs on the pots:-



Rear view showing my average point-to-point wiring:-



And finally located in my new Arturia Rackbrute case:-



I think the rusty panel sits well in the new case haha!

The aluminium attentuator panel to the right was knocked up by my son in his "workshop." He had a bit of a mishap with his sanding belt and removed more material than intended. Does the job though...

[wackelpeter]

Down't know exactly when i finished it. It either was late in 2019 or early in 2020.

Some kind of expansion for my crappy modular synth lab.

Here we have in this box 2 6 step Serge programmers, 4 gate to trigger converters, 1 Serge smooth & stepped generator, 3 Serge Bi-directional switches, 1 Yusynth VC glide, 1 Ian Fritz delayed pulser, 1 Yusynth CV standard and 2 crappy switches for logic signals.

Programmer Box

[latrohexus]

And finally located in my new Arturia Rackbrute case:-



I think the rusty panel sits well in the new case haha!

The aluminium attentuator panel to the right was knocked up by my son in his "workshop." He had a bit of a mishap with his sanding belt and removed more material than intended. Does the job though...

That looks awesome, the Mad Max aesthetic definitely works for it. I started on some blank aluminum panels a couple weeks ago that came with my case as placeholders, and just packed as much stuff into them as I could. My first project was a passive mult that I since upgraded to buffered (with a bonus attenuator that I turned into a deadbug amp for bumping line signals up to modular level), you can see how much the holes wandered:

A drill press is definitely the ideal way to go, but not having one I found that I have the best luck hand drilling if I mark the point and then drill nearly all the way through with a much smaller bit, and then finish with the final size. The small bit seems to wander less, and gives the point of the larger drill a precise path of least resistance. Sharp bits wander less, too, since they tend to walk around when one edge is duller than the other. That method worked a lot better on my next project, the 4x passive attenuator, though they're still not perfect. I also switched up the wiring method and colors after the first (log) one, so I'll just be annoyed by the inconsistency forever because I'm not going to re-do something that already works.