DPDT On-on-on switch wired as 3 SPST?

[nosamiam]

I'm working on a phaser project and I'm having trouble wrapping my head around something. The PCB is set up for jumpers to select how many stages the phaser has -- 2, 4, or 6. The board has 3 pairs of pads, one pair for each stage. Rather than jumpers, I'd like to wire a 3-position toggle switch. Space is at a premium so a rotary switch isn't an option. It would be really nice, but there simply isn't room. I'm reading online that I can maybe use a DPDT on-on-on switch to accomplish this. Can anybody confirm this?

Here's what the PCB looks like:

(The pads for the stages are a little bit above the Krautrock Phaser logo)

And here's what my online searches are saying I can do to make it work (the left column):



In my head, I can't figure out which pads get wired to which lugs on the switch. Coffee isn't even helping. If someone can explain it to me that would be great. But even if someone can confirm that this is possible, at least I can order my switch and figure it out when I get it.

[slacker]

We'd need to see the schematic. It  might be possible depends how the pads need connecting and if any of them are common. It will probably need a triple pole switch though.

[nosamiam]

Unfortunately, the schematic doesn't include stage selection. I can maaaaybe guess where the switches would go on the schematic but I'm not sure.

http://jhaible.com/legacy/compact_clone/jh_krautrock_phaser_sch.pdf

This is really tricky. I think I need 3 poles AND 3 throws AND I need it to connect each one pole. I don't know if this is doable. I think the right slide switch would work but I don't wanna mess with trying to machine a square hole.

I played with the idea of putting a 3 position DIP switch array there but none of the ones I could find would fit neatly in that spot. Bummer... that would have been really classy. Still would have had to open the enclosure to make changes though. I may be stuck with jumpers.

BUT... I bet I can use some PCB mount header pin-type jumpers like hard drives use!! With the little sleeve that makes connections!! That way I don't need to desolder/solder to change the number of stages. Mouser, here I come!

[blackieNYC]

Could you simply use an On Off On, and Off is all stages, On-1 taps in after the 2nd stage, On-2 taps in after the. 4 th?  The center of the switch is the end of the last stage going into the output buffer or whatever you e got there? Maybe it's more complicated than I think.  I'm looking at the Phase Royale BYOC schem.

[nosamiam]

Could you simply use an On Off On, and Off is all stages, On-1 taps in after the 2nd stage, On-2 taps in after the. 4 th?  The center of the switch is the end of the last stage going into the output buffer or whatever you e got there? Maybe it's more complicated than I think.  I'm looking at the Phase Royale BYOC schem.

I couldn't figure out how to make this work. The center of the switch is the switch's input. The two outer lugs are your output choices. So as far as I can tell there's no way to get three choices with an on-off-on switch. Unless the on-on-on would somehow work.

I'm good to go though. I decided to go with pins and a shorting jumper that I can move around.

[potul]

Hi

I took a look at the info you provided ... and after some reverse engineering, I think the pads in the PCB are just selecting where to put the feedback loop.

So it is choosing if the 18k resistor (R63 in the schem) is connected after the stage 2, 4 or 6. The schematic shows position 2.

So at the end you need a SP3T switch. You can simulate this with an on-on-on like in the picture below



A is any of the 3 pads below the "STAGE" mark, they are indeed the same point.

Give it a try and let me know if it works