Strat Blender Mod question

[pablogilberto]

Hello!

I'd like to understand what happens with this Strat Blender Mod:

www.mojotone.com/support/Schematics-for-Pickups-and-Guitars/wiring-diagram-strat-blender


I know that it the blender pot will introduce/blend either the neck or bridge when it is engaged (1 to 9).
And it will go back to a regular SSS strat wiring when blender pot is at 10.

I'm okay with that.

What I want to understand is this. When the blender pot is from (1 to 9),
it looks like the two pickups are in parallel BUT one pickup will actually be in series with the resistance of the blender pot.
How does this variable resistor (blender pot) control the fade-in? Is the resistance of the blender pot directly proportional to the amount of fade in sound? Why or why not? 

Also, what if I wired 2 pickups in series and then I added a variable resistor in series with them. What will be the result?

Thanks!

[thetragichero]

our own JohnH has a post about series blend options here: guitarnuts2.proboards.com/thread/6762/blending-coils-series

here's an interesting one from our dearly departed ChrisK, where you can change from series to parallel blending via a dpdt switch (note that this requires a special blend pot. i prefer bourns mn taper blend pot myself): guitarnuts2.proboards.com/thread/3863

I'll wait for the other folks to chime in wrt tho *how* your parallel blend actually works, but at least I've given you something to chew on in the meantime ;-)

[JohnH]

Ive tried that kind of blender, and it works quite well. By adding a resistance in series with one pickup, that pickups contribution is suppressed, and the other gets through relatively more easily.

Think of two equal rivers meeting, but one has been dammed and a weir added to let only a small amount through. The mix of waters is then mainly from the other river!

It's not linear. Most of the audible mixing action happens in the first few k of added resistance. So use a log pot, using the same two lugs as a normal tone pot.

At 10, the blended pickup is almost entirely suppressed. But, its not quite the same as no blending at all, its a bit less sparkly. I believe this is not about the sound of a little bit still getting through, its about loading due to the pot. It's a great idea to use a no-load pot, which gives you the full range of blending, and then cuts out completely.

As a variation, you can wire this to blend just say, the bridge to the neck, but not the other way around. Less range tonally, but it let's you preset a tone at the neck, while still being able to flick quickly to pure bridge.

This whole idea doesn't work in series, where the resistance will suppress both pickups. Series blending needs a different arrangement, and if done properly is actually more interesting tonally IMO.

[pablogilberto]

Dec 17, 2019 9:49:00 GMT -5 thetragichero said:

our own JohnH has a post about series blend options here: guitarnuts2.proboards.com/thread/6762/blending-coils-series

here's an interesting one from our dearly departed ChrisK, where you can change from series to parallel blending via a dpdt switch (note that this requires a special blend pot. i prefer bourns mn taper blend pot myself): guitarnuts2.proboards.com/thread/3863

I'll wait for the other folks to chime in wrt tho *how* your parallel blend actually works, but at least I've given you something to chew on in the meantime ;-)

Hello thetragichero

I cannot clearly see the photos here: guitarnuts2.proboards.com/thread/3863
It is blured. 

Thanks for your reply!

[pablogilberto]

Dec 17, 2019 15:54:30 GMT -5 JohnH said:

Ive tried that kind of blender, and it works quite well. By adding a resistance in series with one pickup, that pickups contribution is suppressed, and the other gets through relatively more easily.

Think of two equal rivers meeting, but one has been dammed and a weir added to let only a small amount through. The mix of waters is then mainly from the other river!

It's not linear. Most of the audible mixing action happens in the first few k of added resistance. So use a log pot, using the same two lugs as a normal tone pot.

At 10, the blended pickup is almost entirely suppressed. But, its not quite the same as no blending at all, its a bit less sparkly. I believe this is not about the sound of a little bit still getting through, its about loading due to the pot. It's a great idea to use a no-load pot, which gives you the full range of blending, and then cuts out completely.

As a variation, you can wire this to blend just say, the bridge to the neck, but not the other way around. Less range tonally, but it let's you preset a tone at the neck, while still being able to flick quickly to pure bridge.

This whole idea doesn't work in series, where the resistance will suppress both pickups. Series blending needs a different arrangement, and if done properly is actually more interesting tonally IMO.

Thanks for explaining this, JohnH!

Yes, I'm using a No-Load pots for this.
That way, I can go back to a standard strat wiring scheme when the No-Load is at 10.

Since the variable resistance is in series, am I right to assume that when the resistance is minimum (pot at 1), the blended sound is louder and then while the resistance goes up the blended sounded becomes quieter.
Did I understand it correctly?

How would you wire if you want a blended pickup in series?
Do you have a sample diagram for this?

Thank you!

[thetragichero]

shows up fine for me but i uploaded it to imgbb

[newey]

At this juncture. we should mention that the diagrams from the late ChrisK are part schematic, part diagram, and all Art with a capital "A". They can be daunting at first to the uninitiated, so if you need help deciphering any of this, just ask.

[pablogilberto]

Dec 17, 2019 23:12:56 GMT -5 newey said:

At this juncture. we should mention that the diagrams from the late ChrisK are part schematic, part diagram, and all Art with a capital "A". They can be daunting at first to the uninitiated, so if you need help deciphering any of this, just ask.

Hi newey!

I actually don't understand it. Can you teach me how to decipher so I can read it all by my self next time?

Thanks mate!

[JohnH]

For series blending, there are two or three ways, shown here:

guitarnuts2.proboards.com/thread/6762/blending-coils-series

It needs some switching of some kind to get the pickups in series, when they are normally in parallel. There are a number of such schemes in the schematics subforum.

[pablogilberto]

Dec 18, 2019 1:31:02 GMT -5 JohnH said:

For series blending, there are two or three ways, shown here:

guitarnuts2.proboards.com/thread/6762/blending-coils-series

It needs some switching of some kind to get the pickups in series, when they are normally in parallel. There are a number of such schemes in the schematics subforum.

Thank you!

[axedoctor]

hmmm ... the equivalent circuit model for a passive single coil pickup would suggest to me that the series resistance of the blender potentiometer has its primary effect in conjunction with the volume potentiometer voltage divider

that said, it would seem that the blend effect would be altered as the volume is adjusted

is this, in fact, what occurs when you operate those controls during performance? (remember, I'm a just keyboard guy who approaches these topics mostly from an engineering perspective)

[JohnH]

Dec 19, 2019 15:21:58 GMT -5 axedoctor said:

hmmm ... the equivalent circuit model for a passive single coil pickup would suggest to me that the series resistance of the blender potentiometer has its primary effect in conjunction with the volume potentiometer voltage divider

that said, it would seem that the blend effect would be altered as the volume is adjusted

is this, in fact, what occurs when you operate those controls during performance? (remember, I'm a just keyboard guy who approaches these topics mostly from an engineering perspective)

Regarding the parallel blender in the OP, I'd say the volume pot setting is not too critical. The main divider is Pu1 plus blender resistance vs Pu2. The volume pot is too high to make much difference to that interaction.