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Convert Blend pot to DPDT switch?

E

Electricblue

Feb 1, 2011
1,204
49
Norfolk
#1
I'm trying to fit a DPDT in my Jazz but I'm still trying to keep the aesthetics the same.

Could I cut the trace half way on each half of a blend pot and use it as a rotary DPDT?

Think about it :smug:

It will be for a Series/Parallel mod so is it worth cutting the trace at all?

Just ordering parts at the moment and cant find a rotary DPDT :rollno:

Thanks :)
 
#5
line6man said:
No.

Not without modifying the resistive element to conduct at 0 Ohms throughout the rotation.
Click to expand...

That sucks :eek:

Wouldn't it have to be infinite Ohms?

I would rub all of the trace off, apart from each far end of the scale. So one end of the rotation would connect the center terminal to one outer terminal, then most of the rotation is nothing, then the other end connects the center terminal to the opposite outer terminal?

It seems like a lot of effort, but I do tend to make things complicated for myself...
 
#6
Electricblue said:
That sucks :eek:

Wouldn't it have to be infinite Ohms?

I would rub all of the trace off, apart from each far end of the scale. So one end of the rotation would connect the center terminal to one outer terminal, then most of the rotation is nothing, then the other end connects the center terminal to the opposite outer terminal?

It seems like a lot of effort, but I do tend to make things complicated for myself...
Click to expand...

If you want a switch, you would need the entire rotation to be 0 Ohms, with a break in the middle where the wiper will "switch" from one side to the other. Any resistance on the resistive element means a series resistance between the wiper and either side that will increase as you move toward either extreme.
 
#8
Electricblue said:
I'm trying to fit a DPDT in my Jazz but I'm still trying to keep the aesthetics the same.

Just ordering parts at the moment and cant find a rotary DPDT :rollno:
Click to expand...

you could just wire up the m/n pan pot as a DPDT, and get a knob that fades from one sound to the other as you turn it. thing is, it would act more like an on/on/on version, so at the center detent you'd have single coil operation.

back to the original question, Invalid Link Removed for that. they also have 4-pole 3-position versions; i use them both for guitar stuff.
 
#11
Electricblue said:
I'm trying to fit a DPDT in my Jazz but I'm still trying to keep the aesthetics the same.

Could I cut the trace half way on each half of a blend pot and use it as a rotary DPDT?

Think about it :smug:

It will be for a Series/Parallel mod so is it worth cutting the trace at all?

Just ordering parts at the moment and cant find a rotary DPDT :rollno:

Thanks :)
Click to expand...

You don't want to do it this way. I wire my jazz basses two ways either of which would work for you. The first and simplest is to replace the blend pot with a 4 position 3 pole rotary switch (see Mouser). It is wired to give neck pickup only, both in series, both in parallel and bridge pickup only. Works very nice for adjustments while playing.

The other version Is a vol/blend setup with an added series parallel switch. This leaves a bit to be desired but does allow you to blend pickups rather than to always choose an equal mix. The way it works is the circuit is identical to the usual vol/blend with pickups parallel. When you flip them into series, the blend pot doesn't work so well as almost all of the adjustment range is crammed against the ends of the rotation! BUT, nevertheless the blend pot DOES work well as a pickup SWITCH if you just turn it to max and not worry about blending, especially in series connection.

Both these mods have worked out very nicely for me.
 
#12
As the original question was formulated: Yes, that will work. When the pot is at either end you'll get full from the corresponding pup, and nothing from the other. In any intermediary position it will be somewhat funky.

However, there's little point in the mod, as I see it. You'll still have to turn the pot all the way, and there will probably be very little difference from how it works already in the extreme positions.
 
#13
Why not use a 4-position rotary switch and add the pickups in series.

Here's one I did back in '85. I used a 4 position 3 pole switch.

4-pos_series-parallel.gif
 

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