HELP with new jazz bass blend pot

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Hi, I just adquired a new Di Marzio set of PUP's for my Fender jazz bass, I also replaced the blend pot, but instead of blending the signals of the PUP's it works more like a volume control, in the center position there is no signal, and if you start to turn it either side for example clockwise the neck pickup's signal starts to be heard and viceversa.

What is causing this are the pickups out of phase?
 
Are you sure you replaced the Pot with the Right Value and Taper as Before and you conected it correctly......

I assume that this Pot would be a Linear pot and not a Log Pot and to create the Blend function each pickup would be connected to each side of the Pot with the output coming out of the wiper of the Pot, so with the Pot at 12:00 you would get an even blend of each Pickup, and when you turn it in either direction it would make one pickup louder and the other quieter....

Is this how you have it wired up???


Cheers


PS: it shouldn"t be out of Phaze if you have the hot wires of each pickup going to the Blend pot and both have a Common Ground...
 
Minion said:
Are you sure you replaced the Pot with the Right Value and Taper as Before and you conected it correctly......

Yes I replaced it with the recommended pot for this pickups its a 500k audio taper pot, I connected it like in the attached pic (from stewmac.com).

Minion said:

PS: it shouldn"t be out of Phaze if you have the hot wires of each pickup going to the Blend pot and both have a Common Ground...

Yes they share the same ground.
 

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Yes, it is definitely that... Ive removed the pot and measured resistance between the center lug and each other, at center detent position.

From center lug to left lug my tester measures 500k and from center lug to right lug it measures 0. My old pot measures 125k on each side.


What kind of pot is this? in which application one may want a pot having cero resistance at its center position?
 
I have personally never seen a Blend Pot like that...a 250K Linear Pot would measure 125k on each side at the 12: 0 Clock position.....

Most Blend Pots I have used were Linear Taper pots with each side going to each Pickup and the output being the wiper, so when the Pot is at 12: oClock each side sees equal resistance so each Pickup passes the same signal through the Pot but when you turn the pot the resistance increases on one side but decreases on the other side which which increases the Volume of one pickup and decreases the volume of the other pickup......

Try a Linear Pot and connect the hot wires from each Pickup to each side and the Wiper to output and the blend function should work.....

The pot in your drawing looks like a Dual Ganged Linear Pot that is wired in series so each gang of the Pot controlls the signal for each Pickup and they are mixed together by being wired in series and I believe the one side is wired in reverse or is a Reverse taper.... It seems that doing what I explained above does the same thing but with a less expensive pot and less wireing.....


Cheers
 
Stewmac makes mention that it is an audio taper pot, not a linear pot and that image is the recommended wiring for that pot,

I bought it from Allparts and the description they give is the same blend/balance audio taper pot.... I will have to buy another one to see what is wrong the pot or me.
 
You have the output and ground connections on the pot reversed. Switch them and it should work as normal.

In other words, when in the center, you have both sides shorted to ground, rather than shorted to hot.

Artie
 
I guess you already figured it out, but in a blend pot, the internal carbon trace only goes halfway around. In the center, its the same as being at either extreme on a regular pot. You can make that extreme either ground or "hot", depending on how you wire it.

You wired it "wrong". 😀

Artie
 
i use a similar wiring setup for a phase reversal pot. the difference is that the pots are linear taper with a center detent, and the "output" and "ground" connections go to the neck pickup, and the other 2 connections go to the bridge pickup. with the pot at one end, the pickups are in phase (really bassy), at the other end out of phase (really bright), and at the center detent, the bridge pickup is out of circuit. this, however, would not work with the type of pots you are describing.
 
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