They’re annoyingly expensive and hard to find, I agree.
The way the sub osc works is:
The fact that the subtri works, leads me to believe the subsquare and subsaw work too, as it’s created from those. That makes me suspect the switch. Anyway, some scope images should provide clarity 
Huh, I think I see what you mean 
Can you touch the scope probe around the contacts of the switch? See if you can find the hidden saw there.
Yeah, it’s there. I feel like digikey may have led me astray. Their description (SP3T) doesn’t match the datasheet/MFR part number (DPDT).
I’m sorry that happened to you, that’s so annoying. I got mine from aliexpress, but the ad is no longer online. These appear to be the same ones:
€7,29 | 5Pcs SH T80-T T812 Standard Handle 6Pin ON-ON-ON 3-Way SP3T 6.35mm Panel Mount Mini Toggle Switch
(costumary aliexpress caution applies)
Waves not centered around 0 volts, or maybe osilloscope not set to DC coupled mode..
it was a joke. Look at the one labelled “Saw”
Hihi. Its a triangle. Not saw. Well ramp up and down put together you will get a triangle
woosh? It’s a square, because the output of the square sub osc is being duplicated due to the wrong switch being employed because DigiKey hates me.
Replaced the switch and still only getting triangle and square out despite seeing a saw on the pins. I’m at a complete loss. Probably going to leave it as is since swapping the switch out did a real number on the pads. They probe fine to the pin header but I don’t want to risk making it all worse
I’m trying to wrap my head around this SP3T switch behavior. The datasheet for this (and other) SP3T switches shows the input pin is #2 with the outputs on #1, 4, and 6.
but the schematic for the VCO shows the input on #3 and outputs on #1, 2 and 4.
Am I (probably) misreading something? Does the footprint adjust for this?
Hey!
Yes my footprint numbering is different. Here’s a snipper from the PCB, looking at it from the bottom. It appears to be a mirror image from what you show me here. Which data sheet is this from? The switches I have here are labeled Salecom T80-T. Perhaps their working is mirrored wrt yours..
God this is annoying, sorry about that. When I made this, I thought about what happens if the switch is rotated 180 degrees (nothing), but I hadn’t thought about mirror images
That’s actually some random switch I found on mouser, but it matches what is listed for the SP3T (Salecom T80-T) that I purchased on aliexpress here:
Well I’ll be, I just found the exact image in the Salecom T80-T datasheet:
https://static.rapidonline.com/pdf/75284t_v1.pdf (page 14, the switch type is T812)
Seems like the mystery has changed from “why doesn’t it work for you” to “why does it for me”?
I am cursed, if that helps at all.
No it doesn’t help at all! Has that ever helped you??
It helps explain a lot. Doesn’t really solve many problems though, I will admit.
