I’m not sure if the title best describes what I’m looking for so I’ll try to explain better here:
I already have a sequencer that I am happy with (the LMNC Arduino Nano one), however it does not produce it’s own gate signal, therefore needing another module to tick it along. Currently I have been using another 8-step sequencer that I built a while ago and that never fully worked, however I wanted to free up some space in my rig and therefore am looking to build the simplest clock generator/sequencer (I don’t even really want any CV out or anything) that I can just whack on the back and wire straight into my already-existing main sequencer.
Phew, that was exhausting! If I missed something or my description is too confusing, I would be happy to clarify further and answer any questions - Thank you!
I think this is what I’ll do. I’m still learning my circuit diagrams, how do I wire the pot when there’s only 2 connections to it, do I do the middle and right pins (if facing the shaft)?
It depends on if you want the resistance to go up or down as you turn the knob clockwise. In this case you probably want the clock rate to go up so you want the resistance to go down. So middle and right it is. Conventionally one also connects the left pin to the middle, I’ve never really understood the reason and it isn’t absolutely necessary.
The only more or less plausible explanation I saw is that if your pot is junk and the wiper sometimes doesn’t make good contact, you still have some resistance instead of being disconnected.
A better solution would obviously be to use a better pot…
I’ve drafted a diagram if someone could take a look? Although I am expecting errors/mistakes etc. - this is the first time I have ever created a stripboard schematic based off a circuit diagram, I’d like to think I did a decent job.
Cheers.
Your -12v needs to go to pin 11. Also you should ground the remaining non inverting inputs (pins 3, 10, and 12) and tie the remaining non inverting inputs to their respective outputs (1 to 2, 6 to 7, and 13 to 14). I forget why but I know it is recommended for the chip to function properly no inputs should be left “hanging”. Seems a waste of 3 good opamps tho. You could use a Tlo72 and use the remaining opamp as a buffer for an activity led so you can see the rate… Other than that the -12v needs to go to pin 11.
The current limiting resistor on the output doesn’t need to be 100k. There may have been a need for such a high value in Klein’s sample and hold but if this is for an output jack, 1k would be the more normally used value. 100k might work, but if the downstream module has a typical 100k input resistance, it’ll result in a factor of 2 reduction in the voltage.
It’s good practice to add bypass capacitors. 100 nF ceramics from the chip power pins (4 and 11) to ground, placed as close as conveniently possible to the pins, and 10 µF electrolytics from the ±12 V rails to ground near where they connect to the board.
In DIYLC you can reduce the opacity of the chip to make the trace cuts visible.
Some simplifications to your layout are possible. There is a jumper from row E to row I and a resistor from row I to row H. You could just put the resistor from row E to row H and omit the jumper. Similarly instead of the jumper from row F to row J, you could move the resistor and green wire to row F.
The blue jumper not only should go to pin 11 but should come from the bottom row.
Just to be sure: are you looking for a clock to advance your sequencer, or are you (also) looking for a gate out signal for your sequencer?
If merely looking for a simple clock, then I would suggest looking for ‘40106 oscillator schematic’. With this you can get a square wave oscillator clock signal with only 3 components: 40106 chip, potentiometer, capacitor.
If also looking for a gate signal that is only one when the clock signal is high (as opposed to the CV signal of the sequencer, which normally is on the entire step), I suggest looking at the schematic in the manual of the Moritz Klein x Erica Synths DIY Sequencer: Erica Synths - EDU DIY Sequencer
It includes both a clock and a gate out, if you are looking for both.
Sorry, I’m not too clued up on the old terminology. I am just looking for a clock that can go very fast and advance my sequencer - is it not gate signals that do that?
Then I suggest adding a 40106 oscillator with the square wave output, like this:
You can leave out the switch and use one electrolytic capacitor. Just try with capacitors with different values to find a speed range that appeals to you. For instance 1uF/2.2uF/4.7uF/47uF.
For the 40106 IC: pin 7 = GND, pin 14 = +12V (it works at 3V to 15V)
Basically the same as what I posted above. It used a 1M pot and a 470 nF capacitor for a similar speed range. It also used a small series resistor (2.2k with the 1M pot) to set a maximum frequency. The 4093 serves the same purpose in this instance as the 40106.
