Fralin Blender pot quesion - load of blended pickup on full blend

[ibo]

Fralin made it very clear that with the blend knob on 10, the blended pickup is completely out of the circuit. However, with the blend knob on 0, which means the blended pickup is now FULLY blended, does this blended pickup see a load put on by the blender?

Lets say the pickup selector is in the bridge position and I'm going to blend in the neck pickup with the bridge. In this case when the blender is on 0, is the neck pickup directly bypassed through the blender and behaves as if it is soldered to the same lug as the bridge pickup? Or will the neck pickup still experience the 250K load of the Fralin blender and thus behave as if it has just gone through a 250K volume pot on 10 before reaching the ACTUAL volume pot of the guitar?

My knowledge of how potentiometers work is very limited, but I am quite curious. Any help will be greatly appreciated.

[ArtieToo]

In a way, you are correct. But in practice, one pickup doesn't really present a "load" to the other any more than any two pickups, when selected together, present a load to each other. The neck pickup, for example, might see a path to ground, through the blend pot in series with the other pickup, except that the other pickup isn't "off" when its blended out. Its still a voltage source. Since the two pickups are picking up different nodes of the string, the level of interaction will go back and forth between being in, and out, of phase. No different than anytime any two pickups are connected together. But now, its through a very high impedance path. (The blend pot.)

Lindy doesn't mention what size pot to use, but I'd imagine its at least a 500k. Maybe a meg. Either way, you could completely eliminate the interaction by using a no-load pot. But I doubt it would be noticeable even at 500k.

If it helps, here's a diagram showing the basic circuit with the blend pot on "0" and "10". The three resistors represent the blend pot, vol pot, and tone control respectively. But remember, the bridge pup would still be presenting a voltage to the other side of the resistor. Its not ground.

[zenmindbeginner]

I have Fralin/Acme blender pots on a couple of my strats.

Surprisingly, every tone on the dial is useable with no weird drop-outs or phase issues.

I fully expected some strangeness but haven't experienced any.

Those pots are simply awesome.

[grumptruck]

Yeah they are nice. I got one and I use it ALOT.

[ibo]

Thanks everyone for your help and comments. I just ordered 2 of the Fralin blenders to experiment with. I'm sure they will find a place among my strats!

[ibo]

A special thanks to ArtieToo for taking the time to construct such a diagram for my educational benefit! I do believe that Fralin's blender pot is a 250k no-load pot, so the resistor on the bottom diagram representing the blender should be at infinite resistance at 10.

According to your top diagram, does the blender on 0 essentially remove it from the circuit?

That is my take of the diagram you've drawn up. I apologize if this shows my lack of knowledge on this issue, but I am only skeptical because a volume knob on 10 still bleeds off treble, so why wouldn't the blender pot on 0? The 2 scenarios seem synonymous to me with the exception of the volume pot using the third lug to ground, so perhaps that is why there is always treble bleed. Clearly, I'm not very knowledgeable about circuitry, so if you can clarify that for me I'd be much obliged.

Thanks again!

[ibo]

A special thanks to ArtieToo for taking the time to construct such a diagram for my educational benefit! I do believe that Fralin's blender pot is a 250k no-load pot, so the resistor on the bottom diagram representing the blender should be at infinite resistance at 10.

According to your top diagram, does the blender on 0 essentially remove it from the circuit?

That is my take of the diagram you've drawn up. I apologize if this shows my lack of knowledge on this issue, but I am only skeptical because a volume knob on 10 still bleeds off treble, so why wouldn't the blender pot on 0? The 2 scenarios seem synonymous to me with the exception of the volume pot using the third lug to ground, so perhaps that is why there is always treble bleed. Clearly, I'm not very knowledgeable about circuitry, so if you can clarify that for me I'd be much obliged.

Thanks again!

I feel kind of dumb answering my own question, but I'm going to give it a try because I just did some self-educating online.

So to answer my first question: YES! Blender on 0 essentially connects the middle and end lug, completing the circuit. The 250Kohm resistance between the middle and opposite lug does not matter because that circuit is left open so no signal goes through it.

To answer my second question: There is a definite difference! Volume knob always bleeds off something even on 10 because the circuit between the two end lugs of the pot is always complete through the wiper lug. The volume pot on 10 has 0 resistance between the input lug and the wiper lug, but 250Kohm from the wiper lug to the ground lug (this is where the treble is bled to ground). With the blender pot, the third lug is not connected to ground, so the circuit is essentially broken there, so there is never any bleed, just a variable resistance between the two used lugs.

DONE! Plz feel free to correct me or add to my explanation if there is anything wrong with what I said.

***Corrected***