Variable phase?

[GoldenVulture]

Re: Variable phase?

Why would you want a graph? You're not making sense to me. You had said I was "wrong", and I'm just asking you to elaborate. It's a straightforward and reasonable request.

OP asked if there was a way to get "to get variable phase", specifically, "[out of phase] at one end, in phase at the other and variable from in between", ... his words. What you and others are talking about with a stereo pot, or dual gang pot, would be able to switch the phase, but only achieve a "variable amount of volume", and act as a typical blending pot. It would not achieve a "variable amount of phase", as phase is either "in" or "out", and cannot be a blend of the two at one time. IMO it would make more sense to simply use a push/pull pot in that case, for simplicity sake and availability of parts.

Looks like you've never heard of Phase Shifting which is a variable manipulation of Phase. Phase pedals have variable phase. Phase switches only produce a fixed 180 degrees phase inversion
- http://www.geofex.com/article_folders/phasers/phase.html -

As Beau says;

It doesn't work like you'd think. It ends up being like a combination volume control and phase switch. One half of the turn is in phase, the other half of the turn is out of phase, and it turns the volume to 0 at the center crossover point. But that variance can be useful,

Approaching centre it is decreasing the phase signal strength in relation to each pole[ + - ], becoming 0 at centre. In this wiring scenario it causes a signal cancellation at centre. I'm going to try something slightly different and see how that works.

Back to your original statement.

It's not possible because you have to have ground at one end of a coil and positive at the other end. You can't have a situation where you have ground and positive at both ends of a coil and still have it induce a current.

This is wrong because you are presuming a wiring scheme that cannot exist and now your wanting me to explain it to you with a diagram.
Why? you know better don't you ?

 

[GoldenVulture]

Re: Variable phase?

I did this years ago with a tapped SSL-5. Works ok.

View attachment 58377

I'd have to think about it to see if you could do it with a humbucker.

You only need to vary one coil, I used a dual gang pot connecting the pup wires individually to each centre lug. I connected the opposite ends of each pot to each other and took my signal from these two connections.Opposite of what your diag shows and dual.

 

[Artie]

Re: Variable phase?

Interesting. Did it perform as you expected?

 

[GoldenVulture]

Re: Variable phase?

Does the same as Beaus hookup. I want to try it making the pot no load at opposite ends on each taper.
I used a 50K pot which I'm going to hack tomorrow in the daylight when my old eyes can see what they're doing.
I'm curious as to what a 1 Meg pot would do.

 

[GoldenVulture]

Re: Variable phase?

So far we're talking passive components.
You could always feed one pup through an Op Amp and split the signal via a pot to the inputs of the chip. [ Inverting and non inverting ] The inverting input puts it out of phase by 180 '. Use the pot to direct more into the in or out of phase inputs. Alternately cofigure the chip so it has variable phase controlled by the pot.

 

[beaubrummels]

Re: Variable phase?

I think there needs to be a delay in here somewhere to truly vary/shift the phase, though.

 

[GoldenVulture]

Re: Variable phase?

Except for this

Alternately cofigure the chip so it has variable phase controlled by the pot.

All the others vary the amount of in phase/out of phase mix which is still a phase displacement but it is fixed, more like a phase blend. Much like having one pup wired out of phase and using the vol pots to balance how much of each you get.

 

[GoldenVulture]

Re: Variable phase?

Is it possible to use a blend or balance pot to get variable phase for a pickup in relation to another pickup?

Thanks, Will

With passive components , no actually; just variable attenuation of the two.

 

[GoldenVulture]

Re: Variable phase?

Does the same as Beaus hookup. I want to try it making the pot no load at opposite ends on each taper.
I used a 50K pot which I'm going to hack tomorrow in the daylight when my old eyes can see what they're doing.
I'm curious as to what a 1 Meg pot would do.

That was a failure. Back to the drawing board.

 

[Zhangliqun]

Re: Variable phase?

"You're wrong", anyway, if you're that confident, I'd be interested in seeing a diagram for "variable phase".

I think he meant that the theories on out of phase pickups in medieval times (yore) turned out to be incorrect.

But seriously, a more practical way to get something like the desired effect is a volume pot for each pickup and just roll one of them back to taste.