How to construct a "3P3T" switch?

[matopotato]

(EDIT: That should probably read "2P3T" instead...)
Reading through the instructions for Cirrus project (based on Ibanez ST-9 Super Tube Screamer) by Aion FX, there are a few options for C3 and C4:


Default is 5n6 and 15n
But 5n6 and 270n
or 4n7 and 68n respectively are also suggested.
I think I could figure out how to use a DPDT switch for a combo of two of the settings, but is it possible to have all 3 variants on one switch?
I keep coming up with something like a 2P3T or 3P3T or ... and my mind starts spinning. I guess it would need three separate positions and all I have seen so far with 3 positions have an "off" as the middle one.
I looked briefly at rotaries, but couldn't think out how one would solve it.

I think one can of course be creative with parallel ones that end up with the target value, but other component values then.
And possibly the 5n6 in two of the combos could provide some other creative solution, and both would be most welcome.
But I am also curious if it would be possible to wire something so that a switch with three positions would allow for those three variants.,

PDF with the full project and full schematic if desired:
https://aionfx.com/app/files/docs/cirrus_documentation.pdf

[ElectricDruid]

If you had a three position On-Off-On DPDT, you could do it - more or less.

You'd have one cap in each position as the "default", which would be the centre-off position of the switch. Switching either way would bring in another cap in parallel. By choosing the two additional caps carefully, you could get three useful sets of values.

I can't see a simpler way. Otherwise, like you say, you need 2P3T.

The typical 12-position rotary switch is available in a 2-pole, 6 position variation, so that would work and you'd use the limit tab to reduce it to three positions only. So rotary switches are an option.

[PRR]

Rotary can be had in 4P3T. Ignore one P.

[AtomicRob]

There are DP3T ON-ON-ON toggles available, for example https://www.mouser.com/ProductDetail/NKK-Switches/M2044ES1W01?qs=VzCF7O64HHWazg0Ig%2FcygA%3D%3D, but it's probably easier (and cheaper!) to use a DPDT in the manner suggested by ElectricDruid. I've done it that way (with a DPDT) also because the DP3T switches use a 4-pole style base and are larger... harder to fit in a tight space.

[matopotato]

If you had a three position On-Off-On DPDT, you could do it - more or less.

You'd have one cap in each position as the "default", which would be the centre-off position of the switch. Switching either way would bring in another cap in parallel. By choosing the two additional caps carefully, you could get three useful sets of values.

Thanks
Yes, I think I understand. Not needed to have the default values in the middle position either, so will try and do some math.

I can't see a simpler way. Otherwise, like you say, you need 2P3T.

The typical 12-position rotary switch is available in a 2-pole, 6 position variation, so that would work and you'd use the limit tab to reduce it to three positions only. So rotary switches are an option.

I have been scrathing my head around rotary, but I guess they key word here is "rotary switches".
I can not see how 2P6T or 3P4T or 4P3T would be able to have all three options.
At least my (current) understanding is that the rotary connects one pole to 3,4 or 6 outputs (12 not so useful here perhaps). But as you turn through the ones available, say 3 different outputs, then the next will also switch the pole.
So if one pole would select C3, then another would be selector for C4 and by the time you are over on C4 you have left C3 and its options.
2 rotaties is fine, although I guess you would have to rotate them in tandem if you want only the three set combos of C3 and C4.

Or I could also be completely missing something about the inner workings of rotaries.
They also take up a bit more space in my experience and can be tricker to fit in a tight case.

[matopotato]

Rotary can be had in 4P3T. Ignore one P.

Thanks!
Yes, I'd choose the most purposeful variant.
Still not sure how to allow three different C3+C4 settings on a single rotary though, given the schematic snapshot above.
For a while I was contemplating trippeling up the whole section, but since there were a dual pot in therel that would be too complex.

Perhaps a DIP switch could work, although one would have to keep to only certain combinations...

[matopotato]

There are DP3T ON-ON-ON toggles available, for example https://www.mouser.com/ProductDetail/NKK-Switches/M2044ES1W01?qs=VzCF7O64HHWazg0Ig%2FcygA%3D%3D, but it's probably easier (and cheaper!) to use a DPDT in the manner suggested by ElectricDruid. I've done it that way (with a DPDT) also because the DP3T switches use a 4-pole style base and are larger... harder to fit in a tight space.

Many thanks!
The DPDT on on on are of two types, and one is like this


That would allow for two separate setting in the up and down positions, but the middle position would engage already connected Caps.
Perhaps there could be some way to calculate that as well to fit the different scenarios, but at least I fail to see that clearly.

Googling some more I realize that one can always bridge various pins causing different options than what is initially presented.
This might serve me as an inspiration or deterrant...

[ElectricDruid]

If you had a three position On-Off-On DPDT, you could do it - more or less.

You'd have one cap in each position as the "default", which would be the centre-off position of the switch. Switching either way would bring in another cap in parallel. By choosing the two additional caps carefully, you could get three useful sets of values.

Thanks
Yes, I think I understand. Not needed to have the default values in the middle position either, so will try and do some math.

It's not a question of maths. The *minimum* cap value *will be* in the centree position because of how this works. You can use the two outside positions to connect additional caps in parallel and *increase* the capacitance, but whatever you do and whatever values you choose, those outside positions will have larger capacitance than the centre position.

I have been scrathing my head around rotary, but I guess they key word here is "rotary switches".
I can not see how 2P6T or 3P4T or 4P3T would be able to have all three options.
At least my (current) understanding is that the rotary connects one pole to 3,4 or 6 outputs (12 not so useful here perhaps). But as you turn through the ones available, say 3 different outputs, then the next will also switch the pole.
So if one pole would select C3, then another would be selector for C4 and by the time you are over on C4 you have left C3 and its options.
2 rotaties is fine, although I guess you would have to rotate them in tandem if you want only the three set combos of C3 and C4.

Or I could also be completely missing something about the inner workings of rotaries.
They also take up a bit more space in my experience and can be tricker to fit in a tight case.

I think you *are* missing something about rotaries - aside from the 1x12 version, they have *multiple* poles; 2x6, 3x4, 4x3.
Check some diagrams online of what different switches look like until you've got it really clear in your head what a 3-pole, 4-throw (3x4) switch is actually doing. Then it'll all become clear how such a thing would enable you to switch multiple capacitors at once.

But yeah, I agree they do tend to be a bit chunky and maybe aren't ideal for trying to squeeze into a box if there's already lots in there.

[matopotato]

If you had a three position On-Off-On DPDT, you could do it - more or less.

You'd have one cap in each position as the "default", which would be the centre-off position of the switch. Switching either way would bring in another cap in parallel. By choosing the two additional caps carefully, you could get three useful sets of values.

Thanks
Yes, I think I understand. Not needed to have the default values in the middle position either, so will try and do some math.

It's not a question of maths. The *minimum* cap value *will be* in the centree position because of how this works. You can use the two outside positions to connect additional caps in parallel and *increase* the capacitance, but whatever you do and whatever values you choose, those outside positions will have larger capacitance than the centre position.

OK, So you cant have one wire going out to the single one for the base case, and the other settings wire go to one in series with it thus making a total of a lesser value? I mean in the second position the single is not connected tus making the firs wire just a loose wire (which might be a bad thing in itsef though)
If so then I would have to use the lowest common in circuit and then connect in parallel which ever is needed to raise or leave.
Thanks for clarifying

I have been scrathing my head around rotary, but I guess they key word here is "rotary switches".
I can not see how 2P6T or 3P4T or 4P3T would be able to have all three options.
At least my (current) understanding is that the rotary connects one pole to 3,4 or 6 outputs (12 not so useful here perhaps). But as you turn through the ones available, say 3 different outputs, then the next will also switch the pole.
So if one pole would select C3, then another would be selector for C4 and by the time you are over on C4 you have left C3 and its options.
2 rotaties is fine, although I guess you would have to rotate them in tandem if you want only the three set combos of C3 and C4.

Or I could also be completely missing something about the inner workings of rotaries.
They also take up a bit more space in my experience and can be tricker to fit in a tight case.

I think you *are* missing something about rotaries - aside from the 1x12 version, they have *multiple* poles; 2x6, 3x4, 4x3.
Check some diagrams online of what different switches look like until you've got it really clear in your head what a 3-pole, 4-throw (3x4) switch is actually doing. Then it'll all become clear how such a thing would enable you to switch multiple capacitors at once.

So far I have only used them to switch between different diode selections for clipping, and then I thought say A belonged to positions 1-3 and B for 4-6 or similar. I was not aware they could do more of parallel settings. I will check it out for sure!
Thanks.

But yeah, I agree they do tend to be a bit chunky and maybe aren't ideal for trying to squeeze into a box if there's already lots in there.

[duck_arse]

https://www.aliexpress.com/item/32947552565.html?spm=a2g0o.productlist.main.15.73f959d9oFg89R&algo_pvid=55599abf-df87-4248-a98d-e186a41b4fcc&algo_exp_id=55599abf-df87-4248-a98d-e186a41b4fcc-7&pdp_npi=3@dis!AUD!4.62!3.93!!!!!@211bf3f116865790246854217d080f!66198619496!sea!AU!0&curPageLogUid=QToH7W5wungE

see above, I dunno why it says 5 position, but you want 2 pole 4 position rotary of that style. you can have stock values pos 1, add just 270 pos 2, cut just 4n7 pos 3, and cut 4n7 add 68n pos 4 ---- if that's what you want - easy peesy.

give me a couple of hours and I'll draw it up for you, maybe.

[duck_arse]

just like that. pick yer caps. if you do use one of those little blue switches, beware the pinouts. the commons are on opposite ends, and the wafers work against each other 1-4, 4-1.


how rude - I've fergotten to turn off the pins layer.

[matopotato]

https://www.aliexpress.com/item/32947552565.html?spm=a2g0o.productlist.main.15.73f959d9oFg89R&algo_pvid=55599abf-df87-4248-a98d-e186a41b4fcc&algo_exp_id=55599abf-df87-4248-a98d-e186a41b4fcc-7&pdp_npi=3@dis!AUD!4.62!3.93!!!!!@211bf3f116865790246854217d080f!66198619496!sea!AU!0&curPageLogUid=QToH7W5wungE

see above, I dunno why it says 5 position, but you want 2 pole 4 position rotary of that style. you can have stock values pos 1, add just 270 pos 2, cut just 4n7 pos 3, and cut 4n7 add 68n pos 4 ---- if that's what you want - easy peesy.

give me a couple of hours and I'll draw it up for you, maybe.

Thanks, that would be great! But no hurry, I am still in Flintlock troubleshooting and Sapphire breadboarding.

What I am not clear over is how pos 1 would be possible to connect C3 one end to north of R5 (or R4) and that same position connecting C4 to ground.
I see the two C's sitting in unrelated places in the circuit so my mind is locked in the need to have two wires, one for each place.
Then As I turn to pos 2 I get two connectors, one for the wire just north of C4 junction and the other to the (new) 270n already sitting on ground. At this point I am thinking that I have rotated the rotor away from position 1 so that or those connections are no longer valid.
But I understand from the replies that it is most likely me not understanding the rotors.

[matopotato]

just like that. pick yer caps. if you do use one of those little blue switches, beware the pinouts. the commons are on opposite ends, and the wafers work against each other 1-4, 4-1.


how rude - I've fergotten to turn off the pins layer.

Is that one or two rotors?

[duck_arse]

see that dashed line? that's how you connect things mechanical on a schematic. there is two [enclosed] wafers, each with a single rotor wiping one of four contacts, simultaneously. the rotor is the common for that pole/wafer. [as drawn, position 1 is normally closed; 2, 3, 4 are normally open.]

[MrStab]

How much audible difference is there really between 4n7 and 5n6? Is the difference worth a possibly-disproportionate leap in complexity? Would 5n1 suffice for all states?

[matopotato]

How much audible difference is there really between 4n7 and 5n6? Is the difference worth a possibly-disproportionate leap in complexity? Would 5n1 suffice for all states?

I can't say yet, but aim to try it out on breadboard first of course.
Reading the build doc it mentions a +8db boost of the mids in stock.
+25db in one of the settings as "promised" in the original
And +somethinginbetween db
And I thought 8 or 25 or 16 might be quite audible.
Then I confess that the "wonder how one would do to switch two locations with three settings" got the better of me, so I called "home"...

[Phend]

wonder how one would do to switch two locations with three settings"

[PRR]

For reference: the four common types of 12-outer-lug $1 switches:

[ElectricDruid]

Thanks Paul! I looked for something like that but didn't find anything so clear.

That one diagram makes a nice summary.

[RickL]

Many thanks!
The DPDT on on on are of two types, and one is like this

{sorry I don't know how to replicate the image when I reply in quotes}

That would allow for two separate setting in the up and down positions, but the middle position would engage already connected Caps.
Perhaps there could be some way to calculate that as well to fit the different scenarios, but at least I fail to see that clearly.

Not to make too big a deal of it, but the switch you posted, while it looks like a dp3t, is actually a sp3t switch, with the addition of the jumper wire as shown in the actual dp3t that you posted below that, which is just two of the 3pst switches in the same unit, controlled by one toggle . You can get three combinations of caps with a dpdt-centre off switch as already described. They're much cheaper than the 3pst versions.