Alright -Short version: I’ve got a fully functioning clock divider!
All of my files (including DIYLC source, and f3d/step/stl/3mf for the panel) for this are in my github here: Modular-Synth-Build/Clock Divider at main · jhitesma/Modular-Synth-Build · GitHub
Long version - buckle up.
So I decided to go with the clock divider circuit shared by Niklas Ronnberg here based on an original design by Matthias Herrmann for his Fonitrokik synth but modified to be non-inverting and added a startup pulse. Sounded exactly like what I wanted so I breadboarded up part of it to test that it would work with 2N2904 transistors and with that test successful started drawing up a strip board layout.
The resulting layout is:
It’s bigger than I wanted, had way more trace cuts than I wanted. And just feels a bit clunky…but…it was fairly easy to build and it works. At least…it does as pictured. The version I built (pictured in an earlier post) almost worked.
Here’s the board without components to make trace cuts easier to see since a few are rather hidden:
It fits on a piece of Tayda “large” stripboard with 4 strips to spare. But I left them on since I designed the panel to mount a full length board (or…so I thought.)
I’m going to go ahead and document the full build here since I haven’t seen that done too much and figure it could help someone just getting started (not that this is a very useful module when first getting started…but…it’s what I documented.)
First thing I do is mark out the cuts to be made on the component side, this is easier than trying to figure out where they go on the strip side and lets me make sure I’ve got them all placed correctly:
Once I’m sure they’re marked correctly I use a single pin header pin to transfer them to the strip side. I just poke the pin in where marked - and then stab it with my marker on the strip side. For multiple cuts in one column - I just count them out instead of transferring them individually:
Oh, that marker I use…I love it. I saw it suggested by Adam Savage on his tested channel and was intrigued enough to order 3 of them off Amazon. They’re great for transferring marks in long skinny holes…and just all kinds of general marking as well - kind of like a long skinny fine tipped sharpie:
Then I double and triple check that everything is transferred and marked on the strip side correctly:
And once I’m confident I get out a small drill and just twirl it in my fingers 2 or 3 times to cut the traces:
After cutting one last sanity check:
Then I start adding jumpers next. I use my 30awg silicone wire for most of these. For shorter jumpers I’ll just use a piece of cut of component lead sometimes (There’s one I did that way on here.)
I strip one end of the wire and tin it:
Then lay it in place and mark it at the hole it will go into (sorry it’s hard to see my mark since this was a black wire…didn’t think that through too well for the photo!)
Then I strip to the mark - tin and solder it in place.
Once all the jumpers are in I add any lower profile sockets and the power connector (I also added D1 here before I remember to take a photo.)
For there it’s like building any other board. I start with the smallest/lowest components and work up. Diodes first, then resistors, small capacitors, transistors, and finally the bigger caps.
Now I discovered my first mistake. I used the board measurements from DIYLC to plan the panel and it’s mounts. But…that only works if you’re using cut off pieces of board - these boards are actually a bit bigger than DIYLC expects resulting in:
The need to drill a new mounting hole that matches my panel.
Also - I positioned the board so the mounts on the panel would clear the jacks…but didn’t take into account where things attached on the board. So this is less than ideal:
Thankfully there’s room I can move those wires behind the reset jack up a few columns to get them the clearance they need in this case.
I also forgot to get a photo of how I did the grounds but you can kind of see it in that photo. Basically I put the jacks in with the ground lugs facing the center and each LED into the panel with the ground to the center. Then bent one leg up and one down so all the grounds tied together. I didn’t really have room to use connectors on the side of the board against the panel so decided to not use them on either side in this case even though I generally prefer having connectors between the panel and board:
But man…that’s a lot of wire to manage!
I still need to lace it up a bit better…but twisting the pairs and soldering it up helped a little bit:
From there it was a simple matter of giving it power and making sure nothing smoked or blew up and the IC socket had correct voltage on the correct pins. Since I did I popped in the IC, put it in my case and gave it a clock signal.
And it worked! Until it got to the 1/64 division and both the 1/64 and the 1/128 came on. Hmmm…oh well, I added those two myself anyway as the original circuit stopped at 1/32. Let’s do a little patch to see how it works anyway:
I may adjust the resistors on the outputs since they do seem a little low. I haven’t measured them yet to see what they’re actually at. But you’ll notice in the video that the LED’s on my noise drum don’t really show up when triggered from the divider and the output from them is quite a bit lower. I do seem to remember Kristian saying he noticed the output from this was a bit low and he changed the resistors in his circuit as a result. (though his circuit uses a different layout on the outputs with a voltage divider since it runs the outputs off 12v instead of 5v…so I may need to make bigger changes to boost that…or…just live with it.)
And what was causing the 1/64 and 1/128 divisions to tie together? If you look at the original stripboard I posted yesterday and the one I just shared you should be able to notice an extra trace cut.
E23 to be exact. The 1/128 output was accidentally bridged to the 1/64 trigger. Added that cut between them and now it’s working as expected!
So - few small mechanical issues that weren’t quite perfect with the mounting hole position and the location of some of the outputs. But I’m very happy with it and the options it opens up.
Kind of want to build a logic utility module now…but need to finish a few others that I’ve already started first - and really can’t wait for those boards to get my seq v4 connected so I can really start to have some fun.