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Dr. Sketch-n-Etch
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Post by Dr. Sketch-n-Etch » Mon Feb 11, 2019 1:14 am

Hey Team!

Here are the first pictures of my handmade Rubicon-2 project. This involves six PCBs:

Core PCB -- the core VCO and TZFM circuitry:
Image

Shapers PCB -- the sine, pulse, saw, suboctave, and Warp/Squish circuitry (note that this board has long trimpots with end screws, because this board will be underneath the Core board, so those trimpots must be accessed from the edge, through holes in the Connector boards):
Image

Panel PCB (top and bottom) -- note that all panel components are arranged exactly like the Intellijel Rubicon 2 -- and like that unit, I've used proper pots for the main functions, and minipots for all CV attenuators. Also note that I had to kludge two resistors together next to the Symmetry Lock switch at the top right to get 806k (750k + 56k) because I didn't have any 806k. Finally, you will notice the dashed lines around the rotary switch. This is where the PCB must be cut, because this switch is fatter than the other components, so this part of the PCB must be recessed slightly, and the three connector pins to the Translator board must also be shortened by pushing them through a bit:
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Image

Translator PCB (top and bottom) -- this board connects the circuit PCB stack to the panel. Those white headers along the bottom will connect out to all the panel jacks:
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Image

Here is the panel PCB plugged into the translator PCB, from the top and the edge:
Image
Image

Connector PCBs -- these connect all the boards together (note the big holes, which are for accessing the trimpots on the Shaper board):
Image

Finally, here is the full assembly, from the top, bottom, and lower edge:
Image
Image
Image

Notice the three connectors from the middle of the Core board to one of the Connector boards. There is actually another 3-pin connector pair that needs to be wired. In any case, those 13 wires, and the little 4-wire connection that routes power from the Core board to the Shaper board, are the only wiring in this entire module. There is no panel wiring at all. Once everything is soldered, this module basically snaps together.

Tomorrow morning I'm going to make the panel, and then I'll post some pictures of the complete module. I also plan to make a brief video.

I've already made a set of the Core and Shaper boards for somebody. I'd be happy to make a full set of six PCBs for anyone who wants them. I'm going to ask $100 for the entire set -- note that I cut and install all of the jumper wires, and there are about 200 overall -- 108 just on the Translator alone!
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Post by Dr Gris » Mon Feb 11, 2019 10:43 am

Wow :woah:

//M

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Post by Dr. Sketch-n-Etch » Mon Feb 11, 2019 11:49 am

So, obviously, I don't have the correct trimpot for the panel. I have used a standard "little blue box" with the screw on top. Since the screw is not on the centreline of the box, I had to twist the box when I soldered it in to get the screw roughly in the middle of the panel. Also, the screw is too high up on the panel. For this first prototype panel, I'm just going to drill a hole where the screw actually is. However, I will source a more appropriate trimpot for this purpose and adjust the layout and the panel accordingly. I'm also not too sure about the height of the trimpot -- the screw may be recessed somewhat...? Whatevs.

Also, I used all green LEDs, because those are the only 3mm LEDs I have on hand. Maybe I'll go and buy some other colour and swap two of them out, but we have about a foot of snow here today, so I'm probably not going anywhere.

OK, enough fooling around -- I gotta go cook a panel.
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Post by tobb » Mon Feb 11, 2019 3:29 pm

crazy! :yay:

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Post by Moog$FooL$ » Mon Feb 11, 2019 6:03 pm

MADNESS!!! :eek:
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Post by Dr. Sketch-n-Etch » Mon Feb 11, 2019 7:00 pm

Also, I used the wrong pots. I used the ones where the solder tabs stick out 0.2" beyond the pot body, but I meant to use the ones where the solder tabs come straight down. I have now changed them. The panel is all cooked and it turned out... perfect!

Image

Wait, no, there's a bubble, in the second U of OUTPUTS. Oh well, just one bubble on a panel that big is rare. Now I gotta drill it -- it's only three drill hole sizes: 1/4" for switches and minipots, 3/8" (pots and jacks), and 3/16" for the mounting holes in the corners. The regular Alpha 16mm pots have 5/16" shanks, but these new ones with the shorter leads have 3/8" shanks, and just look beefier and of higher quality. They're also shiny and look more carefully machined.

I'll be back after a whole lot of drilling, and the big challenge: trying to get all of those parts through all their respective holes.
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Post by Huba-Swift » Mon Feb 11, 2019 9:58 pm

This is coming along fantastically! That's a whole lot of jumpers on that translator board, I don't want to imagine how long that alone took. Seeing the circuitry for the Rubicon, I'm surprised at how much higher the part count is than your typical saw-core VCO. To think that you went through the whole process of designing this circuit, laying out the boards and populating them, DIY-ing your own panel, and assembling everything to create an entirely new module of your own design. That is something I personally find very inspiring and hope to be capable of one day. Amazing work you're doing here.

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Post by Dr. Sketch-n-Etch » Mon Feb 11, 2019 10:05 pm

Huba-Swift wrote:This is coming along fantastically! That's a whole lot of jumpers on that translator board, I don't want to imagine how long that alone took. Seeing the circuitry for the Rubicon, I'm surprised at how much higher the part count is than your typical saw-core VCO. To think that you went through the whole process of designing this circuit, laying out the boards and populating them, DIY-ing your own panel, and assembling everything to create an entirely new module of your own design. That is something I personally find very inspiring and hope to be capable of one day. Amazing work you're doing here.
Well, Huba-Swift, I see you're from "pretty much Vancouver, Canada." Why don't you come on down to "pretty much South Delta" (specifically, pretty much East Ladner) and I'll show you how to do it?

The fact is, I used to build my own prototypes, and then when I was happy with it, I'd pass the schematics onto Danjel and he'd work them into an Intellijel module. Then, at some point, the new modules were coming so fast and getting so complicated that I couldn't really build them myself anymore, so I didn't. However, in this case, I really wanted to build my own Rubicon 2. I also have plans to build my own Quadra and (old school) Planar as well. The main challenge for me is sourcing appropriate parts. I really hate shopping for electronic components.
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Post by sduck » Mon Feb 11, 2019 10:45 pm

Wow! That is really something. Hope I can work out building one of these sometime in the future.
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Post by Huba-Swift » Mon Feb 11, 2019 10:50 pm

Dr. Sketch-n-Etch wrote:
Huba-Swift wrote:This is coming along fantastically! That's a whole lot of jumpers on that translator board, I don't want to imagine how long that alone took. Seeing the circuitry for the Rubicon, I'm surprised at how much higher the part count is than your typical saw-core VCO. To think that you went through the whole process of designing this circuit, laying out the boards and populating them, DIY-ing your own panel, and assembling everything to create an entirely new module of your own design. That is something I personally find very inspiring and hope to be capable of one day. Amazing work you're doing here.
Well, Huba-Swift, I see you're from "pretty much Vancouver, Canada." Why don't you come on down to "pretty much South Delta" (specifically, pretty much East Ladner) and I'll show you how to do it?

The fact is, I used to build my own prototypes, and then when I was happy with it, I'd pass the schematics onto Danjel and he'd work them into an Intellijel module. Then, at some point, the new modules were coming so fast and getting so complicated that I couldn't really build them myself anymore, so I didn't. However, in this case, I really wanted to build my own Rubicon 2. I also have plans to build my own Quadra and (old school) Planar as well. The main challenge for me is sourcing appropriate parts. I really hate shopping for electronic components.
Pm'd :tu:

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Post by JakoGreyshire » Tue Feb 12, 2019 12:02 am

I really wish I could build one of these... I haven't learned how to make panels yet... I'd also have to build a power supply and case for it as I assume this wouldn't fit in my eurorack case.. Oh.... the DIY GAS I guess I'll have to make due with the pictures and possible video on this thread... keep up the good work Dr. S&E....

:tu: :tu: :tu:

Maybe I should get the PCB set and put it on the back burner for a while... :despair:
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Post by kassu » Tue Feb 12, 2019 1:32 am

Very nice "fit to envelope" design, and quite brave indeed to do this all on single sided boards!
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Post by Dr. Sketch-n-Etch » Tue Feb 12, 2019 2:55 am

JakoGreyshire wrote:I really wish I could build one of these... I haven't learned how to make panels yet... I'd also have to build a power supply and case for it as I assume this wouldn't fit in my eurorack case.. Oh.... the DIY GAS I guess I'll have to make due with the pictures and possible video on this thread... keep up the good work Dr. S&E....

:tu: :tu: :tu:

Maybe I should get the PCB set and put it on the back burner for a while... :despair:
Two things:

1) This is a major build, and not really a project for DIY noobies (hell, it taxed my abilities and patience -- I had to step away from it for a few months), and

2) If you use eurorack, then I strongly suggest that you just buy the Intellijel Rubicon 2. It is the same exact circuit, and it rocks. Plus, you'll probably spend less money on it than you would building the gonzo 5U Rubicon-2.
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Post by Dr. Sketch-n-Etch » Tue Feb 12, 2019 3:04 am

kassu wrote:Very nice "fit to envelope" design, and quite brave indeed to do this all on single sided boards!
Thanks! I'm not really sure what "fit to envelope" means, but it sounds cool.

Also, it wasn't brave to do it on single-sided boards. The simple fact is that single-sided boards are all I know how to make. I have been tempted to make double-sided boards, but can't quite figure out how to do the vias (little bits of wire? Rivets?). Also, I really dislike stuffing and soldering professionally manufactured boards with soldermask and through-hole plated vias and silkscreened component guides. For me, they are hard to get right and no fun to work with. I am now so fast and proficient with my single-sided technique that I don't foresee ever doing it any other way. Of course, I would never advocate making a commercial product that way (although I do have plans to do exactly that, and my whiteface ARP Odyssey works well and is full of single-sided boards that look like they could be homemade). But for homemade DIY, it can't be beat, because it can all be done at home.
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Post by adam » Tue Feb 12, 2019 9:02 am

there is some software that turns layouts drawn in inkscape into gerber files, i think you just draw the traces and it creates the solder mask automatically but i'm not sure

http://pcbmode.com/

it was written by boldport who use it to make arty pcb's https://boldport.com/products/conehead/
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Post by Dr. Sketch-n-Etch » Tue Feb 12, 2019 12:50 pm

It looks as if you need about four different software packages to use that, plus you need to know Python. Thanks but no thanks. All I need is Excel (and I print my transfers from Powerpoint, because for some reason Powerpoint handles images for printing better than any other MS Office program).

I originally developed my layout technique for laying out breadboards, because I was very dissatisfied with just improvising them -- they always looked like shit, they often didn't work, and there were flying wires all over the place that had to be handled very carefully. I simply put a breadboard in a scanner and created a picture of it, then imported that picture into Excel and resized the spreadsheet grid so that the corners of the grid fell on the holes of the breadboard. After that, it was a simple matter to make parts that could be shifted around easily on the grid (when I set "Snap to Grid" in the Drawing menu). I also discovered those little kits with the color-coded jumpers and I used that code in my layouts. This made building the boards even easier.

Image

After I started laying out breadboards, my breadboard circuits were so good that you could practically install them in modules. From there, I laid out a version of the Weird Sound Generator on a little protoboard. Again, I just scanned the protoboard and made a picture. However, then I realized that I was just one step away from just laying out my own boards. All I needed to do was learn how to etch and drill. I consulted the internet and came up with a good etching scheme (HCl and H2O2), and bought a cheap drill press from Home Depot (Ryobi, $107 -- still using it -- that thing has paid for itself a thousand times over). I was making useful boards very quickly. For my own purposes, I've never seen any need to do it any other way. I realize that my techniques are probably seen as insane by other people, but they really work for me, and most importantly, it's a lot of fun to do. Creating layouts in Excel from schematics is probably the thing I enjoy doing most. Plus, it really gives me the opportunity to get very close and personal with my circuits, because I am staring at the schematics and thinking hard about them as I do it.

Image
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Post by adam » Tue Feb 12, 2019 1:19 pm

i wouldn't bother if you're etching yourself, it's more a method for doing double sided pcb's with solder mask to be made by a fab house, the 100 jumpers per pcb would be a bridge too far for me personally ;)

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Post by Moog$FooL$ » Tue Feb 12, 2019 6:10 pm

did someone say a Planar??!???!!!!??!!!!

"I also have plans to build my own Quadra and (old school) Planar as well."

:yay: :hail:
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Post by tobb » Tue Feb 12, 2019 7:21 pm

Dr. Sketch-n-Etch wrote: I also have plans to build my own Planar
Yes Diy Planar please! :hail:

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Post by Dr. Sketch-n-Etch » Tue Feb 12, 2019 7:45 pm

The Doc Sketchy Rubicon 2 is all done, and it works perfectly. Here are some more pictures. Compare it to the Intellijel version (not to scale, obviously):

ImageImage

(I desoldered the LEDs and put in new ones, without soldering them, then put the panel on the panel PCB and connected everything, then turned it upside down so the LEDs settled in their little holes, then I soldered them, and it worked perfectly. I even got the pitch-fixing trimpot screw right in the middle of its hole, which is big enough to accommodate one of those plastic trimpot screwdriver thingies.)

This is what it looks like from the back:

Image

The whole PCB assembly just unplugs from the panel, which made the jack wiring a snap:

Image

Notice how the part of the panel PCB with the octave rotary switch is cut away from the rest of the PCB to accommodate the thick-as-fuck rotary switch.

Finally, here's the view from one of my kitchen windows today -- obviously a good day for working on DIY projects, especially since my university is closed today. Notice the little path I shoveled for my chihuahua to do her business.

Image
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Post by Dr. Sketch-n-Etch » Tue Feb 12, 2019 8:20 pm

So, here are the problems:

1) The rate LEDs are reversed compared to the Intellijel version, so that the left LED lights when the triangle waveform is positive. Changing them involves taking the panel apart, so I won't bother.

2) All of the LEDs are too bright. I used 1k current limiting resistors in the LED driver circuits. I'm going to increase these to 2.2k or maybe even 3.3k. These resistors are on the Core PCB, so accessing them is easy.

3) All of the LEDs are green. Maybe I'll change the rate LEDs to some other color, and reverse their polarity at the same time. However, I'm going to have to buy them first.

Here are the differences from the Intellijel Rubicon 2:

1) The Intellijel unit has a bipolar Expo FM control. I designed mine so that it can be either monopolar or bipolar depending on the position of a wire jumper on the panel PCB. I strongly prefer monopolar control for this function, because it is difficult to turn the bipolar control completely off, so I wired it up monopolar. Also, I don't really understand the desirability of bipolar control for this -- the only use would be to reverse the polarity of an incoming sawtooth modulation signal.

2) When we were developing the Rubicon 2, it was pointed out that the Warp output was a little too hot because at full Warp, it expanded the signal to 20Vpp. I developed a limiting circuit that held the output to 10Vpp across the entire Warp field, but Danjel thought it was too boring to justify the circuitry. Danjel opted instead for the Squish circuit, which is a single-stage wavefolder (straight out of the uFold). This also limits the Warp output to 10Vpp, but adds an interesting timbre. I still really liked the limiter, and it worked like a dream, so I added it to my version, so both Limiter and Squish are available on the Squish switch.

Other than that, the Doc Sketchy unit is identical in functionality to the Intellijel unit.
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Post by syncretism » Wed Feb 13, 2019 6:44 am

Dr. Sketch-n-Etch wrote:
Well, Huba-Swift, I see you're from "pretty much Vancouver, Canada." Why don't you come on down to "pretty much South Delta" (specifically, pretty much East Ladner) and I'll show you how to do it?
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Post by Dr Gris » Wed Feb 13, 2019 10:07 am

I like it when in/outputs are offset like you've done it when there're so many.
Makes everything so much easier.
I only have one "gadget" (16 ins and 16 outs on one panel) that use that idea.

//M

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Post by Moog$FooL$ » Wed Feb 13, 2019 6:27 pm

Fortunately there doesn't seem to be any "business" visible at the end of the path. :razz:
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Post by JakoGreyshire » Thu Feb 14, 2019 1:07 pm

Dr. Sketch-n-Etch wrote:
JakoGreyshire wrote:I really wish I could build one of these... I haven't learned how to make panels yet... I'd also have to build a power supply and case for it as I assume this wouldn't fit in my eurorack case.. Oh.... the DIY GAS I guess I'll have to make due with the pictures and possible video on this thread... keep up the good work Dr. S&E....

:tu: :tu: :tu:

Maybe I should get the PCB set and put it on the back burner for a while... :despair:
Two things:

1) This is a major build, and not really a project for DIY noobies (hell, it taxed my abilities and patience -- I had to step away from it for a few months), and

2) If you use eurorack, then I strongly suggest that you just buy the Intellijel Rubicon 2. It is the same exact circuit, and it rocks. Plus, you'll probably spend less money on it than you would building the gonzo 5U Rubicon-2.
You think this would cost more than 399.00$?
I could build this, I’m not a noob.
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