Another Blend Pot Idea

[Rusty Fingers]

Here's another blend pot idea for a two humbucker guitar:

First, "borrow" a couple of artie's drawings

http://www.artietoo.com/images/blend-a-split.jpg

and

http://www.artietoo.com/images/coil_blend01.png

Use a blend pot for each humbucker like shown on the first sketch. For the second sketch imagine a mini switch swaping the stud coils between pickups.

Now, you have the option to blend the adjustable coil of one pickup with the stud pickup of the other pickup. Besides all of the blend options, in swap mode and both pickups selected on, it would give you the option to spin back to either pickup wired in parallel.

This does assume that the adjustable coils of each pickup are the same phase...don't know if this is a good general assumption.

Just an idea.

Rusty

 

[Artie]

Re: Another Blend Pot Idea

Interesting idea. If I follow correctly, it would be like considering each coil as a "quadrant". You could blend and choose between any quadrant, or combo of quadrants. Rather than be limited by two pickups per se.

I like it.

 

[gordon_39422]

Re: Another Blend Pot Idea

You could blend and choose between any quadrant, or combo of quadrants.

You have put into words what I have been trying to describe for some time now, once again Artie, you have saved the day!!!

Allen

 

[Rusty Fingers]

Re: Another Blend Pot Idea

The things you won't get are both adjustable pole coils in series, both stud coils in series or all coils in parallel. Otherwise lots of possiblilities.

 

[Artie]

Re: Another Blend Pot Idea

This is going to require two pots, right? A joystick has two pots . . .

Hmmm . . . .

 

[Rusty Fingers]

Re: Another Blend Pot Idea

This is going to require two pots, right? A joystick has two pots . . .

Hmmm . . . .

......so we could use it as a kind of tremolo???? OH GAWD!

Getting past the issue of how to mount and wire a joystick to a guitar, am I going to have to drill a hole in the case to let the joystick stick through????? :laugh2:

 

[Rusty Fingers]

Re: Another Blend Pot Idea

.....then I wondered whether you could blend the coil swap, instead of using a switch.

It would take two pots, one for each slug coil. Preferably, two pots on one shaft so that the swap occurs evenly between pickups (think of this as taking a dual concentric pot and "pinning" the shafts together, so that both pots act together).

Wire the slug coils to wipers of the pots and wire the adjustable pole coils to the ends of the pots. At 10 the slug coils could be wired to their normal adj. coil. At 0 the slug coils could be wired to the opposite adj. coil. Seems like this part would work.

In between, both slug coils would be wired proportaionately to the both adjusable coils with varying resistance in the circuit between the coils. Don't know what this would do. Anybody know?

Rusty

 

[Artie]

Re: Another Blend Pot Idea

Its a good idea, and one that I've played with on paper. The problem is, and this all gets back to the fundamental problem with dual volume controls, is that you're dealing with a passive circuit. No matter how you wire it up, at some point, you'll have resistance in the circuit in some intermediate setting. Thats a pretty big amplitude hit in a passive circuit.

Possible solutions are:

1. Go with the amplitude loss, and compensate with onboard pre-amps, ala the SFX-01 circuit board, or the D-Tar Eclipse, on-board buffer/mixer.

2. Build a small active mixer right into the switching/fading system. This, of course, implies having the design skills to do this, and risking altering the basic "tone" of the pickups.

3. Skip the "fading" part, and go straight to switching techniques only. There's a lot that can be done this way, and switches won't attenuate the signal.

Normally, I would question whether or not any of this was worth the hassle, but I found, in my Strat, that the switch to combine one coil of each 'bucker in parallel, was an interesting and worthwhile option. Zionstrat did the same thing with three pickups in his Strat, and liked it.

Its an idea that has potential.

 

[Artie]

Re: Another Blend Pot Idea

Something like this might work:

The two vertical pots would be ganged. One would split the pups, the other would fade-to-parallel the second coil.

 

[Rusty Fingers]

Re: Another Blend Pot Idea

3. Skip the "fading" part, and go straight to switching techniques only. There's a lot that can be done this way, and switches won't attenuate the signal.

The switching mod that I have been considering for some time now is 2 humbuckers with the following:

Neck Volume with push-pull, Bridge Volume with push-pull and Master Tone with push-pull. Each volume pot push-pull would be series/parallel for its pickup (pretty standard stuff). The tone push-pull would be coil swap.
The coil swap would get outside coils and inside coils which would then be in series or parallel based on the setting of the volume push-pulls.

These controls seem pretty intuitive to me. Of course, since I'm looking at a guitar with 4 pots, I need to figure out what to do with the leftover pot position, I was thinking varitone, but then I found the spin-a-split posts here. Now my thinking is totally clouded, so I'm still trying to work this out.

For a strat though, I really do like the concept of two 5-position switches which select the A and B coils separately. With a master volume, master tone and spin-a-split for the selected pickup setting, it seems very flexible, very intuitive and relatively easy to control.

Rusty

 

[Rusty Fingers]

Re: Another Blend Pot Idea

Something like this might work:

The two vertical pots would be ganged. One would split the pups, the other would fade-to-parallel the second coil.

Artie,

I guess we were posting at the same time. Your sketch looks interesting. I'll have to study it for a bit though. Thanks,

Rusty

 

[rspst14]

Re: Another Blend Pot Idea

Somehow, I have this mental image of Artie playing an '85 Peavey Razer with a couple of Atari joysticks sticking out where the volume and tone controls used to be. :laugh2:

Ryan

 

[Rusty Fingers]

Re: Another Blend Pot Idea

After thinking on this for about a week, I there is a way to blend all four "quadrants". I call this the "Look Ma No Switches!" wiring, but yeah, I like the term quadrant wiring too, Artie. Again, two humbucker guitar, the "a" coils of each pickup in same phase, the "b" coils of each pickup in same phase.

Connect the black wires of pup to output.
Connect the white wires of each pup (the A coil) to each end of a blend pot (at center detent, both coils are on full, at the end positions only one coil is on full)
Connect the red wires of each pup (the B coil) to each end of a blend pot (similar to the A coils)
Connect the green wires of each pup to ground.
Connect the output (middle) of the blend pots together.

Then add a blend pot for the blend-split option that will split to either A or B coils....connect one end of the blend pot to output, the other end to ground and the "middle" to middle connection of the other two blend pots.

What this gets you:

Blend A coils of each pickup independantly, blend B coils of each pickup independantly and blend-split between between the already-blended A and B coils.

With all pots in center detent, the neck and bridge pickups are both on, wired sort-of normally, except that the red and white wires of both pickups are all "bridged" together.

With the A and B coil blend pots at the same end position it will get you one pickup with the A and B coils wired in series. With the A and B coil blend pots at opposite end positions, it will get you the A coil of one pickup wired in series with the B coil of an other pickup.

The blend-split pot will then let you blend down to just A coils or just B coils. If the A and B coil pots are at the end positions, it will get you down to a single coil. If the A and B coil pots are in the center position, it will get you down to two coils in parallel.

To finish it off I'd add a master volume and master tone. So you've got a 5-pot guitar with no switches. Might be hard to control in performace but an interesting studio guitar with lots of intermediate blend positions.

Rusty